Sensory Impairment

This weblog post looks at impairments related to the senses, hearing and seeing, in particular. It is targeted at older (60+) readers. Younger people are more adaptive when it comes to using technology to reduce the consequences of their impairments. They quickly master technological innovations. Many will receive systematic, professional follow-up and assistance throughout their lives. Those with serious hearing impairments learn sign language and to lip-read. Those with serious visual impairments, especially the blind, learn Braille, and attend special classes. Both groups will have professional help to choose technology that will make their impairments less debilitating. Such is not always the case with people who develop impairments later in life.

Technological overload is a very real problem for older people, even those living without an obvious impairment. There may be several different ways in which such a situation can be improved using technology, but older people with an impairment frequently lack the (cognitive) ability and/ or will to use them all. There are too many choices. The key, then, is to select the one or two different technologies that will maximize their return on time invested.

Web accessibility is increasingly important. It involves making the use of the internet, and the World Wide Web in particular, easier. The World Wide Web’s ( Web Accessibility Initiative (WAI) provides not only resources but also web content accessibility guidelines and checklists. Here are links to some of the resources. The resources section is a good place to start. This can be followed up by consulting these resources: Strategies, standards, resources to make the Web accessible to people with disabilities; Web Content Accessibility Guidelines 2.0; Web Content Accessibility Guidelines 2.0 quick reference.


One major aid to sight impairment, is the use of eyeglasses. These are typically made to correct the specific imperfections of each user’s eyeballs. Glasses are made specifically for screen usage. This blogger used such a pair for several years. They do ease eye strain and the unnatural head contortions that result from using progressive lenses. Currently, the use of a large (27″) screen, appropriately positioned, is now allowing this blogger to avoid having to wear glasses at all.

As an aside, people wanting to make their own eyeglasses, from scratch, may want to consult this YouTube video. Those preferring to make just the frames would benefit more from this YouTube video. Otherwise, this topic will not be developed further, except to say that the French-Italian vertically integrated EssilorLuxottica Group, has been allowed to develop a near-monopoly when it comes to eye-care products.

Background lighting is another important consideration, when using a computer. General information about lighting has been presented in another weblog post written in 2018. Similarly, some of the factors that should be taken into consideration, regarding displays/ monitors/ screens/ televisions has been discussed more recently in yet another weblog post in this series, Media Player.

In terms of computers and hand-held devices, all (?) operating systems provide assistive features. For visual impairments these include switches to allow high contrast backgrounds, large text, and a screen reader. Usually, there are individual controls that allow each of these to be tweaked.

Many older users are unaware that their computers are equipped with a mechanism that will read screen content, and even allow voice commands . In Windows the reader is called Narrator, while the voice commands are part of Speach Recognition, which can be set up to use a microphone for system input.

Apple has an even more sophisticated product, VoiceOver, that is more than a screen reader. It is used on both MacOS and iOS products. It also provide status information (such as battery level) as well as information related to a specific app being used. Voice Control (and not Siri) is Apple’s equivalent program for voice control.

On Android systems the screen reader is an open-source app called TalkBack. However, it also appears under other names, including: Screen Reader, Voice Assistant, SoundBack and KickBack. Voice Access is the Android app for controlling a device with spoken commands.

Speakup is a screen reader for Linux. It allows users to interact with applications and the OS with audible feedback from the console using a speech synthesizer and to navigate around the screen. As usual for Linux, there are multiple programs for speach control. Those interested in this topic are directed to this introductory Wikipedia article.

There be other reasons than vision impairment, including dyslexia, that may require a person to use speech synthesis for text-to-speech (TTS) purposes. For example, an e-book/ e-mail/ web-page can be read to a person doing a menial task (or anything else that provides a cognitive surplus) on a handheld-device (hopefully in a pocket). It is left as an exercise for interested readers to find a suitable app for their purposes and equipment. This wikipedia article, may provide some hints.


For those people who have a hearing impairment that does not require the use of a hearing aid, or choose not to use one, one way to improve hearing is to use over the ear headphones. Recently, this blogger acquired a Logitech G Pro X headset. It comes with several cables and adaptors that allow it to be used with hand-held devices, such as a smartphone, as well as laptop/ desktop devices with assorted characteristics.

One of the first challenges is to keep and maintain order. This means that the headset as well as the cables and adaptors have to have specific locations where they are stored when not in use.

The relevance of the remainder of this webblog post assumes that the hearing impaired person is equipped with a hearing aid, and that it improves their ability to hear in real-life, physical situations such as conversations involving one to a few other people, or other situations such as a store checkout where there can be background noise.

A hearing aid is equipped with a microphone, an amplifier that increases the sound pressure, and a speaker. When the hearing aid is initially set up, or adjusted, the various frequency areas receive differing degrees of amplification.

In addition, many hearing aids contain a telecoil (t-coil) To use an induction hearing loop or the t-coil function on smart phones, a t-coil must be present and activated on the hearing aid.

A t-coil, is a small copper coil in a hearing aid that acts as a wireless antenna that links to a sound system or PA system, delivering customized sound to the hearing aid wearer. It is an option on most hearing aids and is generally in all cochlear implant processors.

Originally used to hear better on the telephone, the t-coil is necessary to hear within a loop system. Just increasing the volume on a hearing aid or cochlear implant doesn’t necessarily improve the clarity. That is the “wow” factor of a t-coil in a hearing loop system. The clarity and understanding is unequaled when listening in a loop.

With a t-coil installed in the hearing aid, the user simply pushes the button or switch for the “T” setting – no additional headsets or receivers are necessary to hear clearly in the induction loop or on the telephone.

The loop system consists of a microphone to pick up the sound (e.g. spoken words) and an amplifier which processes the signal, which is then sent to a loop cable. A loop cable is a fixed wire that is placed around the perimeter of a specific area. This area can be quite large, e.g. a theatre or a church, or quite small, a person’s living room for example or even down to a chair. A loop can even be fitted around the person’s own head (neck loop). The wire then sends the signal directly to the hearing aids of those who are in the room when their hearing aids are set in T-mode.

The telecoil in a hearing aid (also called t-switch or t-coil) is a tiny coil of wire around a core that will induce an electric current in the coil when it is in the presence of an activated loop system. Normally, a hearing aid picks up sound with a microphone and then amplifies the sound. With a telecoil, the hearing aid “hears” the magnetic signal from the loop system and then amplifies that signal.

Other Embedded Systems

Josef Průša is appreciated for his open-source fused deposition 3D printers, He is shown here at the Prusa Research 3D printfarm, in Prague, Czech Republic. Being open-source means that the designs are available for anyone to use or modify. A 3D printer is a typical example of an embedded system, a product with a microprocessor inside. Photo Josef Průša.

In this weblog post, the focus is on you – as a user and maker of products containing microprocessors and software programs, and ensuring that these products meet your specific needs. While people may not currently have all of the skills they need to make what they want, skills can be learned.

Throughout my teaching career, I have had the fortune to meet many disillusioned pupils, both at a conventional secondary school, as well as in a Norwegian prison. While I find these pupils challenging, they have most often not failed themselves, as they have been failed by an educational system that is determined to compartmentalize/ standardize learning experiences, and create cookie cutter automatons out of living and feeling human beings. Thus, I delighted in taking on their specific circumstances to ensure that they could create for themselves something meaningful out of the limited educational opportunity I could provide them.

In particular, I remember two young women who were totally bored with the academic program imposed on them. They just wanted to get through it, so they could take higher education, become nurses and productive members of society. Instead, they were having to spend hours a week studying Norwegian literature, and other equally boring subjects. They decided to enroll in my technology class.

Since they both worked (part-time) at the municipal nursing home, they were well aware of the needs of live-in patients as well as out-patients. In the end they designed a prototype of an automated pill dispenser, for out-patients living at home. This prototype used an Arduino microcontroller. It is my belief that this experience allowed them to preserve their sanity, that had been seriously challenged by, for them, irrelevant writers of a long past, and forgotten age.

One of the most important elements in a technology workshop is the role of design. The essence of design is to specify how something is to be made, even if one cannot make anything oneself,

Suggestion: Spend today, or even longer, thinking of what you need, that is not being provided, or – if it is – has so many defects, that an improved version would suit you better. When you are ready, tomorrow or next year or ???,

STOP the Press! A pandemic has struck, and much of the content written for this post has become irrelevant!

Pre-pandemic considerations

The focus was to be on you using community based, technological workshops. These have many names, including hacker/ maker spaces. The one I know best is the Teknoverksted ved Spiren, the Technology workshop at Spiren = the Sprout.

They may be located inside a school or library. Alternatively, they may a separate entity, that is publicly or privately funded/ operated. Regardless, they provide facilities for learning and making, that use anything from no tech through old tech to high tech tools. These spaces are typically open to youth and adults. In alphabetical order, equipment may include 3D printers, CNC machines, laser cutters, knitting needles, scissors, sewing machines, soldering irons, table saws and welders.

They provide. a collaborative working environment. People spend their time learning and making. Hopefully, they then go on, teaching and helping others to make. Thus, over time, the skill base of the workshop improves, people with experience make more sophisticated products, when these are appropriate.

One of the first of these workshops was Fab Lab started by Neil Gershenfeld at the Massachusetts Institute of Technology (MIT). It is a small-scale workshop offering digital fabrication, or “a technical prototyping platform for innovation and invention, providing stimulus for local entrepreneurship.  It is also a platform for learning and innovation: a place to play, to create, to learn, to mentor, to invent.”One major problem with the Fab Lab concept, is the extensive and costly list of equipment these labs are expected to provide.

Pandemic considerations

During the pandemic, one main concern is mental health. Some people need more help than others to survive through it. Take the weaker sex, men, as an example. Compared with women, men live shorter lives, have worse health, suffer 70% of injuries, commit 75% of suicides, access health services less and delay seeking health services more, spend less time with doctors, focus on physical problems, avoid discussing mental and emotional problems and …. The Men’s Shed movement as a mechanism for resolving some of these issues has been discussed in a previous weblog post.

Single people are especially exposed. It may be hard keeping one’s sanity living with someone, but it is more difficult when one lives alone, and every effort is being made to eliminate social contacts at work and play. Zoom meetings are not a suitable replacement.

During the pandemic, there are also large groups of people who are suffering more than others because of poverty.

Teaching technical skills works best in small groups, ideally individually. Even if workshops are shut down, small groups can meet. The size of the group can vary from two to, say, five. Outdoor, socially distanced events should be possible, augmented with individual on-line meetings. Those who have the technical skills for making embedded systems, are encouraged to seek out those who are most impacted by the pandemic, and help them learn new skills, or provide them with relevant embedded products.

As noted below, the upcoming post, Tidepool (2020-12-15) is devoted to automated insulin dosing, much of it involving embedded systems designed and made by amateurs.

Post-pandemic considerations

As this is written (2020-11-10) an 90% effective C-19 vaccine has been announced by Pfizer. Its main disadvantage is that it has to be stored at extremely cold temperatures. Then (2020-11-16) Moderna announced a 95% effective C-19 vaccine, with significantly reduced storage requirements. This post will be updated with further information when it is , regarding a post-pandemic world.

Upcoming changes:

Originally, the schedule of weblog posts in this series was: 8. Visual impairment (2020-11-24); 9. Hearing impairment (2020-12-01); 10. Dexterity impairment (2020-12-08); 11. Mobility impairment (2020-12-15), and 12. Computing: A Summary (2020-12-22). This has been changed to the following: Sensory impairing 2020-11-24) – which combines hearing and visual impairment; Dexterity/ Mobility impairment (2020-12-01); Telemedicine (2020-12-08) – which looks at telemedicine generally; Tidepool (2020-12-15) – which examines automated insulin dosing.

Update: On 2020-12-13 at 12:30, Tidepool (2020-12-15) has been changed to Nightscout. It still examines automated insulin dosing.

James Bond

Len Deighton (left) teaching Michael Caine how to crack an egg, on the set of The IPCRESS File (1965). Michael Caine played the role of the spy Harry Palmer, who – in many ways – was the antithesis of James Bond.

Ian Fleming (1908 – 1964) did not provide readers with James Bond’s birthdate. Thus, one is forced to use John Pearson’s (1930 – ) fictional biography, James Bond: The Authorized Biography of 007 (1973), that gives it as 1920-11-11. Thus, the publication date of this weblog post is exactly one hundred years after Bond’s fictional birth, despite John Griswold’s attempt, in Ian Fleming’s James Bond: Annotations And Chronologies for Ian Fleming’s Bond Stories (2006), to put the date one year later, 1921-11-11.

Readers expecting a celebration of the life, books or films of James Bond will be disappointed. In this #MeToo age, James Bond films are simply inappropriate, especially regarding relationships between the sexes, and the use of violence to resolve disputes. In addition, there is no need for anyone with less than one million dollars in net worth to support the ultra-rich owners of the film franchise.

Instead, the pods many people are condemned to live in during this pandemic should be encouraged to make (and share) their own fun videos. Hopefully, some will involve suggestions for an improved post-pandemic world, with an emphasis on kindness and solidarity.

Since Margaret Thatcher (1925 – 2013) and Ronald Reagan (1911 – 2004) imposed a libertarian/ neo-liberal experiment on the world, the result has been the creation of a cadre of the super-rich that seem to be living in the spirit of James Bond, taking advantage of the vulnerable economically, as well as sexually. Not infrequently, they have been able to use the police, the courts, and the legislatures to impose their will, and their values that negatively impact the lives of the majority, leaving destitute the people most in need.

Hopfully, when the pandemic is under better control, people will develop their own scripts, find actors to play heros, and other talent to develop a small production team that can make very local films. Another hope is that an informal network will distributing these films freely through cyberspace, for the benefit of the many.

In the commercial film world of the past, the antithesis of James Bond was Harry Palmer. Periodically, I re-watch these films, and have even re-read some of the novels, upon which they are loosely based. Michael Caine (Maurice Joseph Micklewhite Jr., 1933 -) portrays a realistic character that is capable of living by his wits. Wikipedia writes, “Len Deighton [(1929-)] introduced the lead character in The IPCRESS File, his first novel, published in November 1962…. Deighton’s spy is described as working class, living in a back street flat and seedy hotels, and shopping in supermarkets. He wears glasses, is hindered by bureaucracy, and craves a pay rise.”

Who could ask for a better hero?

In the British espionage novel/ spy fiction genre, Ian Fleming ranks no higher than the ninth best author, on my personal list. In addition to Deighton, other notable authors ranking above him are John Buchan (1875 – 1940), Compton Mackenzie (1883 – 1972), Graham Greene (1904 – 1991), Elleston Trevor (Trevor Dudley-Smith, 1920 – 1995), Alan Stripp (1924 – 2009), John Le Carre (David John Moore Cornwall, 1931 – ), Robert Harris (1957 – ). At the top is Erskine Childers (1870 – 1922), especially The Riddle of the Sands (1904). There are also worse authors in the genre, including Sapper (Cyril McNeile, 1888 – 1937).

James Bond works for MI6, which is concerned with overseas threats. Its retirement age is 60. This means that Bond should have retired in 1980. It is left as an exercise for the reader to determine if the world would have been a better place if he had.

Note: Since this post was written, Sean Connery (1930 – 2020), who portrayed James Bond in seven films from 1962 to 1983, has died. I will now admit that From Russia with Love (1963) is my favourite James Bond film. Perhaps, I should also confess that I was more enchanted by Ursula Andress (1936 – ) in her role as Honey Ryder in Dr No (1962), than I was by Connery.

Connery’s childhood in working-class Edinburgh probably had more in common with the fictional Palmer than the fictional Bond. In his autobiography, Being a Scot (2009), he recalls: “When I took a taxi during a recent Edinburgh Film Festival, the driver was amazed that I could put a name to every street we passed. ‘How come?’ he asked. ‘As a boy I used to deliver milk round here,’ I said. ‘So what do you do now?’ That was rather harder to answer.”

Connery was pre-deceased by; Barry Nelson (of Norwegian ancestry, born Robert Haakon Nielsen, 1917 – 2007), an American actor, who had the first Bond role, in the CBS television production of Casino Royale (1954); David Niven (1910 – 1983), who appeared as Bond in Casino Royale (1967); Roger Moore (1927 – 2017) who played Bond in seven films from 1973 to 1985; Honor Blackman (1925 – 2020) who depicted Pussy Galore in Goldfinger (1964); and, Diana Rigg (1938 – 2020), who had the role of Countess Teresa di Vicenzo, James Bond’s wife, in On Her Majesty’s Secret Service (1969).

Amendment: 2020-11-12. Only seven authors of Spyfi are listed as being better than Fleming. Alan Stripp (1924 – 2009) is missing in action. However, some people may regard William Somerset Maugham (1874 – 1965) and Alistair MacLean (1922 – 1987), as more appropriate for the list.

Smart Home Devices

This charming resident of Cliff Cottage, Hardy, could be taking on new responsibilities as a voice activated room controller. In this role, s/he would need to be fitted with a Raspberry Pi microcontroller, a Power-over-Ethernet circuit, microphone, speaker and other hardware,

Note: The content provided here is an updated, abridged and modified version of a weblog post titled, , that dealt mainly with the use of room controllers.

My preferred term for this subject area is not smart home, but domotics. Yet, not everyone appreciates Latin terms, when perfectly good Anglo-Saxon ones exist.

Part of the reason for my dislike of the term, smart home is the ascription of smart to basic electronic devices that are dependent on sensors and logical circuits, to actuate motors, lights and heaters. Another part of the reason is the use of home. For many people, this is an emotionally loaded term for a residence. I suspect some public relations/ advertising agency imagined that substituting home for residence, house or building would result in increased profits. Admittedly, there are other, more obnoxious phrases than smart home, such as the internet of things, a phrase I increasingly avoid.

Various dictionaries show the noun domus refers to house, home, family, household (with dependents), school (of philosophy). The adjective, domestic, is in common use in a variety of contexts. As a noun, it can refer to a hired household servant. Hopefully, in the future it will refer to a robot offering similar services, although dombot could emerge. If it does, expect puns contrasting dombot with dumbot.

MQTT Broker and clients

At the heart of any domotic device is communication. Andy Stanford-Clark and Arlon Nipper authored the first version of the Message Queuing Telemetry Transport (MQTT) protocol in 1999. The name is a misnomer, as there are no queues with MQTT. Typically, there are numerous clients, and at least one (and potentially more) message brokers. A broker receives all messages published by clients and then routes these messages to subscriber clients. In a household, a client is usually a micro controller, perhaps a Raspberry Pi, while the broker is typically software located on a Network Attached Storage (NAS) server.

In a home automation situation, publisher clients are attached to sensors, and they publish sensor data; subscriber clients are attached to actuators, typically motors, but also heaters, vents lights and much more, that they regulate, at the most basic level – turn on or off.

The two most common open source home automation systems using MQTT are: open Home Automation Bus (openHAB), a project started in 2010, with code written in Java; and, Homa Assistant, started in 2013, with code in Python. While Home Assistant has been praised for its privacy features, it has been criticized for its file-based setup procedure. Recently, it has become more user friendly and accessible, with a simplified, web-based graphical user interface. An iPhone or Android hand-held device, can also be used as controller. This is especially important when one wants to control features remotely.

Brokers and clients manage: lighting, temperature and humidity (indoor climate), audio and video (entertainment), unauthorized access, smoke/ fire detection (security) and related services. Here, it is only considered in terms of a residence, but almost all types of buildings can use these: barns, shops, manufacturing facilties, etc. While it might appear that micro-controllers are in charge, managing these services using algorithms, most systems can have their decisions overridden by humans.


Wireless communication, using Bluetooth or WiFi, should be avoided, if possible, for most domotic/ smart home automation hardware, because there will always be throughput and power issues with these technologies. The one exception to this rule is the use of hand-held devices, including mobile phones and tablets, that use apps to function as remote controls for the system. These apps can be downloaded from the appropriate device app provider.

In the previous millennium, it was not uncommon for people to wire their houses with Ethernet cable. People who did so, and have not removed them, are the real winners. The reason for this is that room controllers need to communicate, and to communicate they need power.

The various Ethernet cables were standardized for different speeds. Cat 3 provided 10 Mbit/s in a standard presented in 1990. Cat 5 increased throughput to 100 Mbit/s in 1995, and then to 1 Gbit/s in 1999. Cat 5e offered 2.5 Gbit/s in 2016, while Cat 6 increased it to 5 Gbit/s, the same year. The Cat6A standard, is actually ten years older, dating from 2006, but provides 10Gbit/s.

The advantage of Power over Ethernet (PoE) is that it eliminates the need to install separate power cables. PoE technology sends the above mentioned 10/100/1000 Mbps of data and 15W, 30W, 60W, and up to 90W of power to devices over Cat5e, Cat6 and Cat6A Ethernet cables for a maximum distance of 100m. Cat3 and Cat5 cable can also be used with restrictions, They supply of 48 V with a maximum current of 400 mA using two of the available four pairs of wires on Cat 3 or Cat 5 cable. While this appears to provide a maximum power of 19.2 W, system losses will normally reduce this to under 13 W.

MQTT Software and supporting hardware

The household’s MQTT broker is typically a software program, housed in a server. Wifi-based handheld devices connect to the broker using Wifi, while Ethernet-based room controllers connect to it through cables, and a switch.

A switch is a box that allows multiple other devices in a local area network to be inter-connected. A typical commercial switch may have up to 48 different ports for cables connected to 48 separate devices. Home oriented switches typically have 8 ports.

Business users commonly sell off their equipment once the warranty period has expired. Servers as well as switches can be purchased by private individuals inexpensively, because businesses won’t buy used (read: out of warranty) equipment, and most people don’t know what the equipment can be used for.

Cables usually run between the switch and other devices through the walls of the house, although there is nothing to prevent more visible wiring, along walls/ ceilings/ floors. If people are considering remodelling their house, adding Ethernet cable is no real issue. Whatever cable is used, it will ultimately pay to use the fastest Ethernet cable type currently available that supports PoE. Cat 6 is more readily available than Cat 6A. Using either means that the cable won’t have to be replaced anytime soon. Hopefully, the cables will last 30 years, or more.

Room Controllers

Control units, like all devices, needs power. Power over Ethernet (PoE) is an ideal way to provide power, since Ethernet connectivity is the preferred approach to wired data communication. PoE eliminates the need to install separate power cables. Each controller is provided with power from the switch itself.

Several different types of microprocessors can be used in controllers, including Arduino, ESP and Raspberry Pi. At Cliff Cotttage, Raspberry Pis are used.

Room controllers, and similar devices, are one of the main categories of devices that need PoE connections. A typical unit could use a Raspberry Pi Model B 3+, sensors connected to general purpose input-output (GPIO) pins. with a PoE hat (hardware on top, which provides extra capabilities) to provide power and cooling, and – in addition – a Pimoroni Automation HAT to provide support for actuators. Some room controllers would have a 7″ touch screen. Others would be fitted for voice communication with microphones and speakers.

A Pimoroni Automation HAR on top of a Raspberry Pi Model B (Photo: Piomoroni)

Controllers need to be placed in the following locations: 1) access control at entrance doors; 2) living room; 3) dining area; 4) kitchen; 5) bedrooms; 6) study, studio and workshop areas. A few people may want to have controllers in 7) bathrooms and/or laundry rooms, while most prefer to avoid this. In addition, there shouldl be 8) PoE access points for WiFi. This allows WiFi connections in parts of the house that are inaccessible for direct signals to and from the server.

Other switches, without PoE, can be used for other devices dependent on higher power levels. These include: 1) a home theatre connections; 2) a printer and/ or scanner; 3) clothes washer and/ or dryer; 4) dishwasher; 5)  refrigerator and/ or freezer; 6) stove top and/ or oven; 7) microwave oven; 8) kettle; 9) hot water tank; 10) heat exchanger; 11) heat pump or solar thermal controller; 12) greenhouse controller. Not everyone has appliances with Ethernet connections, but they are increasingly available.

A front-door access controller will typically have an infra-red camera, proximity sensor and infra-red light connected to it, that will be activated as someone approaches. Video of each event will be sent to an external location, that could be located anywhere in the world. A room controller may have proximity sensors as well as other sensors to register temperature, CO2, humidity levels and more. Data gained from these sensors and others throughout a house, can be used to activate lights, or heating, display time, temperature and other data on a touch screen. It can even listen to verbal instructions with a microphone and answer using a speaker.

Recently, a Compute Module (CM) 4 was released. Unlike more conventional Raspberry Pis, the CM is totally flat, but uses the bottom edge for connection. In the future, I hope to acquire a Compute Module 4 Development Kit to develop suitable applications based on these modules. CM boards are used because they avoid unnecessary components, making products potentially cheaper and smaller.

Update of content in Printers, published 2020-03-24:

Owners of H-P and other ink jet printers, are advised to read what Cory Doctorow has to say in Ink-Stained Wretches: The Battle for the Soul of Digital Freedom Taking Place Inside Your Printer (2020-11-05).

Raspberry Pi 400 Personal Computer Kit

The Raspberry Pi (RPi) 400 Personal Computer kit. The keyboard contains a RPi board running at 1.8 GHz (faster than the 1.5 GHz found in the RPi 4 Model B). There is also a mouse/ rodent, a RPi operating system (OS) on a micro-SD card, a (UK, shown here) USB-C based power adapter, an HDMI cable to connect the video and audio output to a display/ monitor/ screen/ television, and an official RPi Beginner’s Guide. Price, about £/ $/ € 100. Photo: Raspberry Pi Foundation.

The pandemic has increased hunger and homelessness, and prevented some people from attending a physical school. This might be because of a legitimate health reason, but in some cases it might just be political. Affected students need digital equipment to access online schooling. Hopefully, this is being provided by the educational authorities, but where it isn’t an inexpensive solution may be needed.

The Raspberry Pi 400 Personal Computer Kit, may be precisely what the teacher ordered. Of course, the machine can also be used for work and entertainment purposes, in addition to education. At a cost of about £/ €/ $ 100 it contains everything one needs in a basic personal computer (except the display/ monitor/ screen/ television). As long as a proposed display supports a high definition multimedia interface (HDMI) connector, it can be used. Unfortunately, even an inexpensive machine like this will not help if the real problem is a lack of broadband infrastructure.


  • Processor: Quad-core 1.8GHz Cortex-A72 (ARM v8) 64-bit (BCM2711)
  • Random-access memory (RAM): 4GB (LP DDR4-3200)
  • Dual-band (2.4GHz and 5.0GHz) IEEE 802.11b/g/n/ac for wireless local area network (LAN) connectivity,
  • Bluetooth 5.0, BLE
  • Gigabit Ethernet for wired LAN connectivity.
  • 2 × USB 3.0 and 1 × USB 2.0 ports
  • Horizontal 40-pin general-purpose input/ output (GPIO) header
  • 2 × micro HDMI ports (supports up to 4Kp60) for video display
  • Video decoders: H.265 (4Kp60) / H.264 (1080p60 decode, 1080p30 encode)
  • OpenGL ES 3.0
  • microSD card slot for operating system and data storage
  • 78- or 79-key compact keyboard (depending on regional variant)
  • USB-C power connector
  • Dimensions: 286mm × 122mm × 23mm

Currently, the English (UK) keyboard (with UK power supply) is available as is an English (US) keyboard with a North American power supply, and a French keyboard with a European power supply. Soon, these will be augmented with German, Italian and Spanish keyboards, with an EU power supply. Beginner’s guides are provided in the same language as the keyboard type: English, French, German, Italian or Spanish. There is no mention of an official Nordic keyboard.

For the first time a RPi has an on/off power switch, activated by pressing Fn+F10 simultaneously. Pressing these for two seconds will turn on power.

Unusually, the mouse plugs into a USB-port at the back and to the left of the keyboard. This makes it ideal for left-handed people. This appears to be a design issue (read: flaw).

A wireless, Bluetooth mouse will not have any such challenges. These cost about £/ €/ $ 7. If this is needed, then one should probably buy all of the components separately. A universal USB-C power supply costs about £/ €/ $ 9. The keyboard module is about £/ €/ $ 67. The Beginner’s guide can be freely downloaded. This results in a total price of about £/ €/ $ 83.

The RPi 4 series is noted for having temperature issues. The RPi 400 contains a heat spreader to dissipate heat from the entire machine, so no part will be too hot. It is claimed that there is enough thermal capacity to overclock = run faster than the design speed.

The RPi’s GPIO header/ interface/ connector is often used for interacting with electronic components placed on a breadboard = electronics test circuit, such as sensors or actuators (motors, for example). This may be only for educational purposes, or it might even serve real-world needs. It is this capability that makes the RPi a much better machine for learning about computers than a laptop or desktop machine.

The smallest and cheapest RPi model, the Zero, at about £/ €/ $ 5, is being used to provide computing power to ventilators being produced from locally available parts in Columbia, South America. The RPi 400 could also do this, but its capabilities far exceed the computing needs of a ventilator.

The RPi 400 PC kit is following a tradition that emerged in the early 1980s, with Acorn’s BBC Micro (1982), Sinclair’s ZX Spectrum (1982), Commodore’s Amiga 1000 (1985) , and others that integrated the motherboard directly into the keyboard. There was no separate system unit or keyboard cable. Just a computer, a power supply, a cable to a display, and (sometimes) a mouse.

The first RPi was launched 2012-02-29. According to the RPI Foundation, this new RPi 400 model, launched 2020-11-02, is about 40 x more powerful than the original. On launch day, Chris Barnat, on his Explaining Computers YouTube channel, made a video describing the RPi 400 in detail. Other single board computer (SBC) influencers, released similar videos.

Vehicle Devices

The Fisker Ocean will be contract manufactured by the Canadian owned, Austrian located, Magna Steyr facility in Graz, Austria. Photo: Fisker, Inc.

While many Americans will be focused on their presidential election taking place today (2020-11-03), this observer is awaiting the result of the Massachusetts Right to Repair Initiative (2020), a referendum appearing on today’s Massachusetts general election ballot. This could update the state’s right to repair laws to include telematic electronic vehicle data. This was specifically excluded on the 2012 referendum that passed with 86% of the vote.

It comes as no surprise that Elon Musk is opposed to the Massachusetts Right to Repair Initiative (2020), and is actively encouraging people to vote no. Right to repair legislation is generally supported by consumers, independent repair/ after-market companies and associations. It is generally opposed by original equipment manufacturers (OEMs), such as Ford or GM, and dealerships.

The Clean Air Act of 1963, is a United States federal law that with the purpose of controlling air pollution. It has been amended several times since then. The 1990 amendments required all vehicles built after 1994 to include on-board computer systems to monitor vehicle emissions. The bill also required automakers to provide independent repairers the same emissions service information as provided to franchised new car dealers. California further passed legislation requiring that all emissions related service information and tools be made available to independent shops. Unlike the Clean Air Act, the California bill also required the car companies to maintain web sites which contained all of their service information and which was accessible on a subscription basis to repair shops and car owners.

Today, microprocessors control operation-critical vehicle systems: brakes/ ignition (on internal combustion engine (ICE) vehicles) / air bags/ steering/ and more. Repairing/ servicing requires computer diagnostic tools. At the same time, OEMs have taken on gatekeeper roles to control information and parts necessary for service/ repairs. Control, in the above sentence, is particularly aimed at restricting access.

Most ICE vehicles use a controller area network (CAN bus) to manage microcontrollers, smart sensors and other devices to communicate with each other without a host computer. Each of these components is referred to as a node, with a hierarchical structure in relation to each other. No two nodes are equal, one always ranks above or below the other. The network features a message-based protocol. When two or more nodes transmit simultaneously, it is always the highest ranking node that is allowed to continue.

The electronic control unit (ECU) is typically based on about 70 nodes, each featuring, say, a 32-bit, 40 MHz microprocessor with about 1 MB of memory. This is orders of magnitude less powerful than those used in laptop or desktop computers.

Each node has to be able to handle a large set of processing tasks. These include: Analog-to-digital converters (ADC) – where a physical property usually measured in volts is converted into a digital number; Digital-to-analog converters (DAC) – provide an analog voltage output to drive some component, with a digital number telling the system what analog voltage to supply; signal conditioners make adjustments to input or output data so that it aligns more correctly with real-world needs; communication standards are implemented capable of sending appropriate signals to other nodes. The CAN-bus communication standard allows for speeds of up to 500 kilobits per second (Kbps) using two wires.

The CAN-bus, and similar devices, simplify vehicle wiring through the use of smart sensors and multiplexing. In ancient times (prior to about 1990) a wire ran from each switch to the device it powered. The circuit was completed by grounding one terminal of the battery to the chassis.

Smart sensors are integrated components, that include not only the sensor, but an ADC and a microprocessor. This allows it to read a voltage, make compensations for temperature, pressure or other factors using compensation curves or calculations, and then send digital output signals onto the CAN-bus.

With multiplexing a microprocessor monitors sensors in one area of the vehicle, such as a door. When that a specific window button is pressed “downward”, the microprocessor will activate a relay that will, in turn, provide power to the window motor so it moves downward.

Among the parts carmakers buy assembled from external suppliers are instrument clusters. These are designed by the supplier to the vehicle maker’s specifications. This is advantageous for both for the maker and the supplier. However, it also takes power away from the OEMs, and gives it to suppliers, such as Bosch or Continental.

Some of the nodes include: Battery Management System (BMS); Brake Control Module (BCM) which may also incorporate an Anti-locking an Braking System (ABS) and Electronic Stability Control (ESC); Door control unit (DCU); Electric Power Steering Control Unit (PSCU) or a Motor-driven Power Steering Unit (MPSU); Human-machine interface (HMI); Powertrain control module (PCM): which may combine an Engine Control Unit (ECU) and a transmission control unit (TCU); Seat Control Unit; Speed control unit (SCU);Telematic control unit (TCU).

Confusingly, ECU is also used as an abbreviation for the Engine Control Unit, which is one specific node. Here, and in many other circumstances to avoid confusion, it will be referred to as an ECM = Engine Control Module. It uses closed-loop control. Depending on the intended usage of the vehicle, the ECM will optimize specific goals: maximum torque, maximum fuel efficiency, minimum emissions, etc.

The CAN-bus allows module to communicate faults (errors) to a central module, where they are stored, then sent onwards to an off-board diagnostic tool, when it is connected. This alerts service personnel to system errors.

With electrification already a reality, and autonomous driving becoming one soon, the CAN-bus methodology will be unable the flow of data. Tesla uses a dual (read: duplicate/ redundant) artificial intelligence (AI) based, Samsung produced microprocessor system, running at 2 GHZ, to control vehicles. Compared to the CAN system, these are extremely powerful,

Volkswagen’s ID3 is going the same route, where it is using high-performance computers (HPC) supplied by Continental for control purposes.

Some vehicle designers do not have the capability to set their designs out in life. A notable example is Fisker. Danish-American Henrik Fisker (1963 – ) has made some exciting vehicle designs, but not all of the businesses he has started have survived. The latest manifestation is Fisker Inc., which was started in 2016. It has presented a SUV EV, Ocean, and a pickup proposal, Alaskan. With the Ocean’s design finalized, it is outsourcing vehicle production of its Ocean to Magna Steyr, a Canadian-Austrian contract vehicle manufacturer. For Fisker, this will reduce manufacturing complexities and costs, in contrast to building and operating its own factory. Magna’s electric vehicle platform, Partial payment for this will be in the form of (up to) 6% stake of Fisker Inc.’s equity, currently valued at $3 billion.

Returning to the Massachusetts Right to Repair Initiative (2020), a yes vote can have dramatic consequences for the computing equipment put on vehicles (ICE as well as EVs) in the future. Starting with the model year 2022, all vehicles with telematic systems, sold in Massachusetts (but more likely throughout the United States, if not the world) will have to be equipped with a standardized open access data platform.

On 2020-10-15, Foxconn, the Taiwanese multinational electronics contract manufacturer, responsible for production of an estimated 40% of all consumer electronics sold worldwide, announced its MIH open platform for electric vehicles. If Tesla is the iPhone of electric vehicles, Foxconn wants to be its Android. Foxconn has been involved in automotive manufacturing since 2007.

Currently, according to Foxconn, the battery pack accounts for 30 to 35% of the total production cost of an EV; powertrain = 20 to 25%; Embedded Electronic Architecture (EEA) = 15 to 20%; body = 13 to 15%; otheto develop and establish an open industry standard for automotive electrical-electronic (E/E) architecturer, including wheels & tires = 10 to 12%.

The MIH platform would be prepared for 5G and 6G, comply with AUTomotive Open System ARchitecture (AUTOSAR) and ISO 26262, and be ready for OTA (over-the-air) updates and V2X (vehicle-to-anything) communication.

AUTOSAR has been in operation since 2003 Its founding members include: Bavarian Motor Works (BMW), Robert Bosch GmbH, Continental AG, Daimler AG, Siemens VDO (until its acquisition by Continental in 2008), and Volkswagen. Later members include Ford Motor Company, Groupe PSA, Toyota Motor Corporation (all 2003), General Motors (2004). Thus, it represents a very large proporttion of the automotive industry. Its objective is to create/ establish an open and standardized software architecture for automotive electronic control units (ECUs). Other goals include “the scalability to different vehicle and platform variants, transferability of software, the consideration of availability and safety requirements, a collaboration between various partners, sustainable use of natural resources, and maintainability during the whole product lifecycle.”

ISO 26262, Road vehicles – Functional safety, was defined in 2011, and revised in 2018.

The MIH platform can accommodate wheelbases from 2 750 to 3 100 mm, with tracks from 1 590 to 1 700 mm, ground clearance from 126 to 211 mm. Three battery packs will be available. Vehicles can be rear wheel drive (RWD), front wheel drive (FWD) or all wheel drive (AWD). Motors on the front axle can be: 95 kW, 150 kW or 200 kW. Motors at the rear can be: 150 kW, 200 kW, 240 kW, and 340 kW. This allows a range of vehicles from a FWD with 95 kW to an AWD with 540 kW.

Part of the MIH strategy is to use mega castings. Foxconn cites one example, where they reduced 7 front suspension body panels to a single cast part and 27 rear longitudinal rail components to yet another single cast part, using a 4.2 Gg = 4 200 Mg (commonly called a ton) die-cast machine.

This post will end with a rhetorical question: What is a vehicle device? There may be many answers, but there are three I would like readers to consider. The first, is that there are subcomponents on a vehicle that could be regarded as devices. Second, the vehicle itself is also a device. Indeed, unlike a so-called mobile phone, which is a hand-held device, a vehicle is a true mobile device. Other potential members of this category include robot lawnmowers, electric airplanes and exoskeletons that are sometimes used by people with mobility issues. The third, is that the production platform is the device.