Tag archives: electronics

Thursday, 6th July 2017 - 15:59:18


Today some cheapo eBay adapters arrived which were advertised as headset splitters, ie one socket for mic and one socket for earphones. These were not them. They were simply two way splitters. They were cheap enough not to complain about so I hacked the plug off and got to work. PS4 controllers use the CTIA standard of plug. So the tip is left, the first ring is right, the second ring is ground and the sleeve is mic. There are some other images if you click the thumbnail to see the gallery.

Monday, 19th June 2017 - 10:46:32

More eBay Loot

A bunch of stuff from eBay turned up at last. I probably won't have to buy a coloured SIL header ever again. More ESP8266s. Some teeny tiny PIR modules which only have a 10mm dia. Some soil moisture sensors and some USB to ttl serial converters.

Sunday, 11th June 2017 - 18:23:07


The new circular 7 way WS2812 boards arrived from eBay and they fit perfectly in the top of these solar lights with some small modifications. Click the image to see the other photos.

Wednesday, 24th May 2017 - 21:34:32

Roadrunner Coloured Wire

My Element14 order turned up with my Roadrunner pencil wire. RRW-A-105 0.19mm solderable enamel wire. The colours will help distinguish some different lines in some upcoming projects (garden lights) where I need to run vcc, gnd and a data line. They need to be fine so as not to obstruct the light.

Friday, 19th May 2017 - 08:11:42


Sonoffs have arrived from itead.cc to play with!

Saturday, 6th May 2017 - 19:30:32


At last the finished product! Fully soldered with paste and hot air, with terminals mounted and mounted in it's DIN rail enclosure ready to go.

Friday, 14th April 2017 - 14:04:00


I have upgraded the firmware and buck converter in the PIR plugpack project. The new code makes use of a ws2812 to display it's status. I have run the LED out on a very thin enamelled copper flywire so that I can use the inside of the PIR dome as a diffuser. It sits out of the line of sight of the pyroelectric sensor.

Friday, 31st March 2017 - 09:00:51


Level shifter powers up. No smoke. Unfortunately it doesn't work correctly because there is more current coming into the base of each transistor than I anticipated. It's enough to hold all transistors on. So I'll try getting some mosfets with the same pinout and seeing how they do.

Sunday, 26th March 2017 - 15:06:48


Playing with the battery powered ESP8266 project again. I've got it down to 9mA. Unfortunately the minium current draw is raised a long way by the buck converter board I have which is rated for 3A - it's much heavier duty than it needs to be and isn't very efficient.

Friday, 17th March 2017 - 09:10:47


I had a go at some SMD soldering with solder paste for the level converter board. It came out OK.

Wednesday, 8th March 2017 - 22:46:11


So I scored a failed Juniper SRX210 off eBay for $1. I figured it was worth a gamble. Well it paid off. After some testing I found that the system was not getting any juice. The input protection diode had failed short. My guess is that someone has plugged in the PSU for the POE version of this firewall (48VDC) into this non-POE firewall (should be 12VDC) and nuked it. I removed it temporarily and powered the unit up on a lab power supply to limit the current. It booted! Score!

Wednesday, 8th March 2017 - 10:49:17

12V to 24V Level Shifter PCB

The PCB for the 12V to 24V has arrived.

Wednesday, 8th February 2017 - 21:03:15


Prototype 12V to 24V level shifter.

Friday, 6th January 2017 - 14:01:08


Today I unpacked my electronics gear and got it set up on my updated bench.

Monday, 2nd January 2017 - 16:56:51


I started work on a sled / stand thing with casters to hold two sets of drawers which will store electronics bits for the lab. This will make them mobile and allow cleaning underneath.

Sunday, 11th December 2016 - 14:21:19


The shelves I built about two years ago received a coat of clear poly to make them look the part for their new home inside the house. They came up really nice and it also gave me the opportunity to redo some of the edge banding which was loose and allowing the shelf to sag (they are only mdf).

Friday, 25th November 2016 - 21:46:51


Lost or misplaced the the power supply for your HTPC? No worries, just fire it up on a lab power supply =)

Sunday, 9th October 2016 - 14:02:08


I decided to unwrap these old BP Solar panels and see what they could do. I built a basic SLA charging circuit that would allow an SLA battery to be charged and to supply power to an ESP8266. This will be for use outdoors as a weather station "or something". I haven't decided yet. Mostly I just wanted to see if the solar panels that I've had for over a decade still worked.

Wednesday, 24th August 2016 - 01:24:12


What's a Loxone and why does the stupid thing have such a low input impedance? The reason is this chip. HVS882. It's an industrial input serializer chip. The input impedance is only 10k. This chip operates in a "window" mode for detecting "on" vs "off". With the recommended 4.7k pullup on a 24V supply, this leaves things very close to the 16V threshold that the chip requires for an "on" state. So I've started using 3.9k pullups which gives a little more room for movement on longer cable runs where a few volts can potentially be lost bringing it under the required 16V.

Monday, 20th June 2016 - 11:38:01

Baby 200kW load bank

Toured the DC facilities today. We walked past one of the "smaller" load banks at 200kW.