Archives 2018

Sunday, 27th May 2018 - 23:48:54

iTead Sonoff Logo

This evening after a session of DarkMatter great progress was made on the SonoffMQTT project. This project aims to replace the firmware on a Sonoff with custom firmware so that it is accessible via MQTT instead of the supplied eWeLink. Having it available on MQTT means it will plug directly into Home Assistant and will be cointrollable from there. After soldering some headers into the board, I was able to power it externally (not mains) and flash it using Arduino IDE.

Sunday, 27th May 2018 - 16:33:36

Arduino Logo

A pretty productive day. The code has now been refactored to accept simple non-json type commands on specific topics ie <uuid>/relay/0/set. This allows the relays to work with the "switch" function in Home Assistant.

Sunday, 27th May 2018 - 13:41:23

MQTT Home Assistant Sensors

After some refactoring of the dual relay board code, it's now reporting temperature, humidity on MQTT topics. This means it will work correctly with Home Assistant.

Saturday, 10th February 2018 - 10:21:46


I received a dodgy batch of DC-DC converters. These are pretty common 12-19V in and 3.3V out. The top one is a dodgy one from the supplier. The bottom one is working unit from another supplier. You can see that the resistor and capacitor (between inductor and chip and between chip and bottom left solder pad) are transposed. They probably just loaded the wrong reels. I can fix these but it's a pain in the butt. The seller ended up giving me a partial refund. The middle is where I've desoldered the R and C and swapped them to their correct positions. The issue, however, is that the R is incorrect also resulting in 3.6V... I'll need to buy some parts and fix them.

Saturday, 20th January 2018 - 20:54:34


This is the "Fairy Jar" night light that I created for my Daughter's birthday. I used some nichrome wire to make a hot wire cutter which allows styrofoam to be easily cut leaving a smooth(ish) edge. On top of that went some artificial grass. The foam and grass was banded with some unicorn ribbon to make it look neat and hide the edges. The mushrooms and lillypads came from an eBay China night light (that you'd never in your right mind actually plug into mains!).  There are also some strings of copper wire with LEDs on them. The fairy and the mushrooms came from eBay. I drilled some 1mm holes in the bottoms of those (they are resin) - Into there I epoxied some pins with the heads cut off. This secures them into the grass/foam. It's all electrically joined up under the foam in the middle. There is a hole which goes through the base and pops up in the middle for the cord. More pics in the gallery.

Monday, 15th January 2018 - 20:37:46


Today I built a prototype relay controller which can be controlled via MQTT, but also has built in temperature and humidity sensors. It uses the temperature data to act as a thermostat turning one of the relays on and off at a temperature set point with a few degrees hysteresis (so that it doesn't go nuts switching on and off if it's fluctuating over the set point). Hysteresis "time" can also be added so that I can use the same code for another controller which will control a fridge. You don't want to be turning the compressor on and off rapidly. To get the temperature, the values from two ds18b20s and a dht22 (not pictured) are averaged.

Friday, 12th January 2018 - 11:27:34


About time for a new cabin air filter on the Barina. I don't think it's supposed to be black like that!

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