Sanyo 1970’s LED clock / radio resurrection (well sort of)

In the quest to make something useful out of a load of old junk I’ve found in my cupboards I came across my old clock radio I’ve had since 1978 a while back and decided to do something with it rather than throw it out. It actually worked but it had an ‘accident’ with the floor a few years ago which had broken the casing and cracked the main PCB.

1970’s clock in new casing with Arduino based temperature display on 7 segment LED’s

I have no idea why I just didn’t throw it out then but I had replaced it with a cheapo clock off ebay which projected the time onto the ceiling with some superbright LED’s and mini LCD’s. Quite innovative but that piece of crap lasted a few months before breaking prompting me to replace it yet again. Well the second replacement failed by randomly corrupting the display and resetting itself. Not ideal if you want to set up an alarm that can reliably wake you up. Acctim? Craptim more like.

On one of my earlier posts I made an alarm clock using an 8051 microcontroller but the alarm was unsatisfactory so in order to avoid more cheap Chinese electronics that doesn’t work I decided to make something out of what remained of the 1970’s alarm clock. The clock PCB was functional as was the LED display but it was very dim and had small segments. It also drew a lot of current (nearly 600mA) and the clock IC, TMS1944AN2L got very hot. I had a Fairchild Semiconductor FCS8000 LED module which is also 1970’s vintage salvaged from another clock but I had a datasheet for this which showed that it is a low current, high brightness module. It draws much less current (and has a bigger display) than the old LED display.

Continue reading

Ebay transistor tester testing

I bought myself one of those cheap transistor testers off ebay based on the Ardutester at https://forum.arduino.cc/index.php?topic=164112.0 which basically is an Arduino project that someone made which the Chinese commercialized and ripped off. It’s actually a great bit of kit but it’s clearly based on an Arduino project that was never intended to be a commercial product.

The Ebay ‘transistor tester’ which does a whole lot more than just test transistors

With the Arduino and good programming and electronics knowledge you can make an end product that rivals a commercial product. Take for example the Ardutester; an open source project that tests electronic components and displays the results on a character LCD. It’s a fantastic project and the designer made all the source code and hardware schematics available for others to make. Seemingly someone in China saw this as a potential to make money, took the source code and improved it then sold it as a commercial product. I’d imagine the creator of the original product would be pissed but I guess there’s nothing you can do about it.

Continue reading

Playing with an 8051 microcontroller

I’ve been using the Arduino for a while now and made a few projects but at work we use the 8051 as the primary micro for our in house equipment. Yeah it’s outdated but Silicon Labs have taken the original 8051 design and vastly improved it with clock speeds of 100Mhz. It can easily outperform an Arduino and technically is a more capable processor.

However support is limited and its for professional programmers only whereas the Arduino is more for hobbyists. Knowledge of the CPU and in depth knowledge of C is required to get anywhere with this. I decided to buy an Atmel version which is more or less based on the original Intel design but it does run at 24Mhz. It also comes in a DIP package too so is ideal for breadboard and veroboard projects.

I found that development kit and software was expensive unless you used the outdated SDCC compiler or BASCOM. Support was lacking and I struggled to make anything useful with it. Compared to the Arduino with it’s libraries etc you don’t need to know how the AVR chip works and there’s loads of help out there.

Continue reading

A WIFI spectrum analyzer and Talk-Talk routers suck A$$

A close relative of mine has been having lots of wifi connection issues over the last few months but just on a couple of devices. A scan of the wifi neighborhood showed only a couple of signals from adjacent houses which were too weak to cause a problem.

I tried changing the channels, 150 or 300 bandwidth modes and even tried dropping to 54G compatibility. The problem would be fixed but return a few days later. I tried disabling the wifi adaptor in one of the affected laptops and used a USB adaptor instead. I couldn’t swap the router as this was needed for IPTV (talk talk) and my replacement didn’t support it. Same problem with different adaptors. What was going on? Mobile phones and tablets were fine; just the two Windows 7 / 10 devices refused to work. I needed to scan for interference and here’s where the Arduino came in.

Continue reading