Martin's corner on the web

Just received one of these optical fluid sensors after 2 months in transit.. No documentation at all, wondering what is the fourth wire for..

Drive your car by any of my home security cameras and they will log your license plate and timestamp. Not sure it is proper or even legal, but it took me 10 minutes to do it with Node-RED and openalpr #security #IoT #AI

Updated a 2014 wireless power consumption monitor project of mine to be compatible with my latest generation project hardware and backend #homeautomation #IoT #esp32

Experimenting with #Samsung #smartthings capable #esp32 smart switch using their SDK and ESP-IDF. There is no need for a hub, works directly with the Smart Things app.

Connected my home alarm system to a secured #MQTT channel and am able to arm/disarm/read state remotely via Node-red powered UI #IoT #IoT #arduino #homeautomation Used the code by https://github.com/maragelis/ParadoxRs232toMqtt

#raspberrypi #flightradar24 monitor using @adafruit 3.5" PiTFT and Chromium in kiosk mode

#ncdu saves the day when my blog VPS goes crazy due to running out of disk space. Turns out a pesky log not being truncated and yours truly not setting an alert for situations like this 😉 https://dev.yorhel.nl/ncdu

Using a 3.5" PiTFT as security camera monitor with a ffmpeg one-liner #rtsp #raspberrypi ffmpeg -rtsp_transport udp -i rtsp://192.168.1.123:554/12 -pix_fmt rgb565le -s 480×320 -f fbdev /dev/fb1

I just activated a http://luftdaten.info air quality sensor, will be contributing from my home in the suburbs that was missing air quality info. Where I live I measure PM2.5 to be 7.8 µg/m³, but overall air quality in Sofia right now is outrageous.

Added FreeRTOS CPU (both cores) load monitoring (for power management strategy implementation) from my TFT32 project. Pleased to see how efficient the code is, CPU load at 8% and 10% respectively for core 0 and 1..

Committing three weeks' worth of changes..phew

Added GUI visualization of a 424-510MHz spectrum scan using RFM69 and ESP32. Note the peak at 433MHz, I was holding a 433MHz door opener keyfob to test it

Picking a free RF channel is fundamental for good link quality. Working on a RFM69 spectrum scanner that will suggest free channel upon pairing a wireless sensor with the gateway. The RSSI spectrum looks like this where I live (suburban), there is an obvious band to avoid:

Experimenting with Atmega328 OTA update over RFM69 wireless link, works fine. Remaining is to implement this+GUI on the TFT32 esp32-rfm69 gateway project, so it can reflash the relay actuators if needed.

Don't trust the 3D model 😉

I rarely use Arduino nowadays, one reason is its amateur-ish IDE. Thankfully there are alternatives like using it within Eclipse C/C++ IDE, which partially deals with my Arduino intolerance in the rare cases I resort to it.

Had to increase a WiFi AP association timeout on an ESP32 project, it was failing to connect in <15 sec. What is the recommended time to wait before considering a connection attempt timed out?

Dealing with bugs..

Added a software low-pass filter on a remote humidity sensor's readings, the result is quite obvious