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Detecting power export.
There are devices that detect when your PV panels are exporting power to the grid - so that you can divert it to heat water or a thermal store, for example. These rely on a sensor...
Wednesday, 2 February 2022 - 11:16
Difference between SSU and SSF parts
I need some more ATTiny44 devices. Farnell have ATTiny44A-SSF, but this product in the past used the SSU part. Am I right in thinking that this is merely a temperature grade...
Thursday, 25 February 2021 - 10:36
Contactless payment card failure mode.
My contactless debit cards seem to stop working after a while. Not for any account related reason, just functional failure. My AmEx card degraded quite slowly, there were a couple...
Friday, 25 September 2020 - 10:02
Handheld ultrasound scanners
Nothing to do with AVRs, but can someone explain to me how the handheld ultrasound scanners detect position/motion? The ones they use on pregnant women, or old farts like me, when...
Wednesday, 29 July 2020 - 08:59
Safely measure 12v boat battery voltage with AVR
I'd like to monitor a 12V boat battery. I don't want to risk damage to the ADC input, what with pumps and things kicking in and out. Would a 50k resistor from the bat+ and a 10k...
Wednesday, 15 July 2020 - 11:50
Dumb MPPT question
I have a couple of small solar panels gathering dust. They have an OC voltage of around 20V. I would like to use them to charge some NiCads, maybe 3 or 4 in series. I have read...
Sunday, 17 May 2020 - 09:40
USART in SPI mode for reading 128 bit stream at 25,000 bps
I will be trying to capture a stream of 128 bits at aprox 40uS intervals. I know I can do this easily with counter/timer interrupts, although the interrupt latency could introduce...
Wednesday, 13 May 2020 - 10:26
Reflow with hot air gun or kitchen oven?
I have a Toyota key fob that seems to have a dry joint or similar. It only works if I twist the PCB slightly. Since these things cost hundreds to replace, is there any mileage in...
Tuesday, 30 July 2019 - 09:55
PIC programming
I expect I'll be Blynched, but here goes anyway... It's all the same happy bunch of pals company now, right? An old client of mine has a bunch of PCBs that I designed several...
Friday, 22 March 2019 - 13:27
Strange Alexa Bluetooth problem.
My wife's Echo dot is usually connected via Bluetooth to a little BT receiver that plugs into the aux input of our dining room "HiFi".   After it's been connected for some...
Friday, 8 March 2019 - 11:12
XMEGA-A3BU XPLAINED yours for postage.
Found this whilst looking for something completely different. I'm probably never going to use it, so yours for postage cost(which I guess limits it to UK).  
Saturday, 2 March 2019 - 14:48
Hi side FET switch for low voltage
I'd like to switch the power to a small OLED display, it draws under 50mA, could be a lot less, but depends on active pixels. It is, however, too much for me to supply the Vdd...
Friday, 18 January 2019 - 08:00