Tag archives: electronics

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

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Prototype 12V to 24V level shifter.

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

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

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

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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

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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

HTPC Lost PSU

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

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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

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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.

Sunday, 24th April 2016 - 22:46:46

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Internet Enabled Night Light. I made this out of an old wall wart and an ESP8266 SOC module. Basically took the guts out of the wall wart and replaced them with the contents of a much more modern wall wart (smaller) which left space for the ESP8266 module, the PIR sensor and other bits. The device uses MQTT to communicate trigger events and periodic measurements to a custom cloud service.

  • Temperature - DHT11
  • Humidity - DHT11
  • Brightness - LDR (Light Dependent Resistor)
  • Movement - PIR Module (DSN-FIR800)

Gallery

Monday, 11th April 2016 - 09:01:21

ESP8266 Prototype Breadboard

Here is a small ESP8266 prototype using a DHT11 and an LDR for light level sensing. This module is super convenient; it has USB to RS232 integrated and also has standard spacing so it can be put into a bread board.

Saturday, 2nd April 2016 - 11:42:45

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The kids broke their iPad charge cable. They are not too hard to repair. I backed up the connector with a piece of cable tie as strain relief and heat shrunk it all together.

Tuesday, 12th January 2016 - 20:00:00

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Lots and lots of pigtails soldered onto LED strips!

Monday, 4th January 2016 - 19:06:55

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I am helping out with a project at work to install LED lighting in our DC. Should be awesome.

Sunday, 3rd January 2016 - 20:37:10

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Had a mate around today for a BBQ and we built some sensors and wrote some code for the ESP8266.

Friday, 18th September 2015 - 20:57:14

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Cleaned out and tested my mates tropical fish tank light. These are really nice. You can adjust blue / white proportions of lights.

Friday, 21st August 2015 - 20:16:32

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eBay score - direct from China of course. Got a bunch of jumpers and also matching 2,3,4 and 5 way connectors.

Sunday, 16th August 2015 - 16:01:21

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I bought a few of these cheap ESP8266-12 modules from eBay. I'm pretty impressed so far with how easy it is to get a simple web server up and running.

Key learnings:

  • The module has a number of IO pins which must have set state to run and another state to flash. GPIO0 needs to be tied low to flash.
  • Needs hundreds of mA - can't run from USB->RS232 converter power.
  • minicom (linux) doesn't send the required CRLF to the module. Have to manually use CTRL+M, CTRL+J
  • Needs to be flashed with NodeMCU firmware to use LUA
python esptool.py --port /dev/ttyUSB0 write_flash 0x00000 ../Downloads/nodemcu_integer_0.9.6-dev_20150704.bin

Saturday, 20th June 2015 - 15:36:16

Philips DLS10 Delay Tube 01

I was given this interesting tube. The Philips DLS10. It's a thermal delay tube designed to delay the switch on of the HT (High Tension) section so that tubes are at temperature before HT is applied. This one is operational.

Saturday, 13th June 2015 - 13:39:20

Bluetooth FM Transmitter

I created this Bluetooth FM tranmitter thingy from two cheap eBay items. Combining them reduces the crap hanging around in the car and means just one cord freeing the USB socket for charging.