1202 ALARM

 I have been a bit lax about putting stuff up here so this is just a link to a YouTube video showing the classic car data streaming system I have been working on in another format from this previous one. Classic Car Data Stream System

  During the first Covid-19 lock down, I bought my son a new Acer Chromebook for home learning, but he decided he preferred the 10-year old Linux Mint laptop he'd been using (and still is, teenagers eh?), so the new computer went to his mum meaning that her 2014 Acer C720 Chromebook was now surplus. I played about with it for a bit, but as Google stopped supporting it with security updates in late 2019 I reckoned it would be worth investigating putting a proper Linux OS onto it. A bit of research led me to the Fascinating Captain's blog http://www.fascinatingcaptain.com/projects/dual-boot-chrome-os-and-linux/ and trial running using live flash drive versions of a couple of Linux distros and I was convinced the laptop was worth upgrading. I bought a 128Gb M.2 SDD for £25 (eBay) to replace the 16Gb one in the C720 and removed the write-protect screw while I had the case apart so that the BIOS could be fully flashed with the excellent update scripts courtesy of MrChromebox. https:...

Just a quick post showing the repaired Acer Iconia tablet in its snappy red cover. In the foreground is a pair of Bluetooth earphones that were another repair job. I moved a 32Gb SD card from another tablet to this one and added a matte screen protector to make the screen easier to read. All in, a great upcycle which I can use for the next few years.

This is just a quick post, really to link to the short video I made below showing my latest data-logging experiment, which takes in a number of technologies. At the core is an Arduino Nano doing the actual logging with code derived from work I did using PIC microcontrollers a few years ago. There are two parts to this - Reading up to 8 10-bit analogue values (range 0-1023); Reading the frequency of a PWM signal. These values are output serially 10 times per second (at 115200 bps) in what I call a data 'frame' which looks like - <AABBCCDDEEFFGGHH> Each frame has 18 bytes terminated by '<' and '>'. The pairs of letters represent a 10-bit value split into 2 5-bit nibbles and these values (0-31) have 64 added to them so that they are displayable ASCII characters to make debugging easier (range is decimal 64-95) Putting these together gives the basis for a data-logging and dashboard display system for my (currently ignored) 1988 Toyota MR2, but it needs a...

My son's Trust gaming headset developed an intermittent fault with the left earphone. Quick investigation revealed one of the connections had come loose. It didn't appear to have been very well soldered originally. A quick 5-minute repair and they are working good as new.  This type of wire is what my father called Litz wire, but reading up on it that might have been incorrect on his part. My grandfather was a pioneering amateur radio operator and almost certainly used proper Litz wire for radio frequency working on shortwave. Anyway, it is a strong and flexible wire suited to applications such as headphones and microphones, but needs the lacquer removed and to be tinned before soldering otherwise you get a poor joint. 

 I received another haul of old electronics from kind Freegle lady Margaret who was having a clear out. There was an old Asus netbook which had died, but it gave up another useful 10.1 inch LCD panel so I have ordered a control board for it on eBay. There were two tablet computers with cracked touch panels, an Asus Nexus 2 and an Acer Iconia. Both tablets booted up and could be reset and used with my Bluetooth combination keyboard and trackpad. A bit of research revealed that the Nexus would be much harder to repair and probably was too low spec to be worth the trouble, whereas the Acer would be an easier repair, was still had a decent spec (Intel CPU and 2Gb or RAM) and had received a final update to Android 7 only 2 years ago. Decision made, I purchased a replacement touch panel for £12 on eBay. Acer Iconia with cracked touch panel (Bluetooth keyboard) While the new touch panel was on its way, I decided to sacrifice the Nexus in the spirit of learning and had a go at removing its...

Over 20 years ago, when we were first getting into PCs, my dad got a Chicony KTP-7903 keyboard in a 'goody' box from Bull Electrical. These were large cheap boxes of surplus gear and could be anything, but always had some interesting stuff in them. We even got parts of the duff Rabbit phone system in one. The keyboard was an odd-shaped thing that was supposed to be ergonomic, but it had a touchpad on the removable wrist rest which was pretty unusual. The device had a full-size 5-pin DIN PS/2 connection for the keyboard and a separate serial (RS232) connection for the touchpad. Pretty soon my dad got bored with the weird keyboard but he had the genius idea of carefully cutting the touchpad off the end of the rest and using it separately. It turned out to be really useful anywhere where a mouse was going to be hard to use. The only problem was that it had a serial connection and by about 5 years ago it was obsolete as even the older computers I use no longer had a serial port. I ...