In this video I’m gonna show the second revision of my esp32, battery powered PIR motion sensor. This second revision contains some optimizations to improve deep sleep power consumption as well as to fix some of the errors I had the first revision of the pcb.
Tag: Espressif
Voltlog #247 – InTheMail
Welcome to a new InTheMail, the series that will touch both your passion for electronics and your bank account at the same time. We’re going to start with this small module, at first when I ordered it I didn’t fully understood what it does but now after doing a bit of research for this mailbag it seems this is an immobiliser emulator for the VAG group. So am immobiliser is a security component of your car that will not let the ECU start the engine unless a certain key or token is present. And there might be valid reasons why you might need this emulator, for example if the immobiliser is broken, you can supposably cancel it and start the engine with this emulator or if you exchange the motor/ecu combo once again it might not be possible to use the old immobiliser and so an emulator will help.
It talks over a K-line interface which is something specific to the automotive domain but it’s basically a form of serial interface. At first I thought this was going to emulate some kind of can bus and I was planning to play with it by scanning the bus but now I realize this is useless for me.
Voltlog #240 – ESP32 PIR Motion Sensor With Deep Sleep & MQTT
Welcome to a new Voltlog, in this video I’m gonna show you how I designed and built this board which functions as an esp32 based, battery powered PIR motion sensor. So I started by designing the circuit, I used some common building blocks, I added the ESP32 with it’s bypass caps, some test points and the programming circuit with auto-reset, I then added some connection points for the PIR sensor, an RGB LED because why not have a nice way to signal this is one of those very small digital RGB leds, it’s just 20x20mm, it’s connected to 3.3V even though it’s only rated for 5V so I’m hoping this is going to work even on 3.3, it’s also worth having a temperature/humidity sensor to also sense that in whichever room the node will be placed and finally the power supply circuit which is a simple low dropout regulator with an 18650 battery as the input.
I did not include a battery charger circuit on this module, because I wanted to keep things simple, I’ll have a battery socket so I can just remove the 18650 cell and charge it separately plus the whole circuit should run in sleep for extended periods of time giving me a long operating time so i wouldn’t have to charge the battery too often.
Once the schematic was finished I did the board layout in a hurry so it’s not exactly pretty or optimized
but I tried to move the esp32 antenna to the side, to place the PIR sensor in the top side as the module will probably sit vertically, I tried to place the temperature sensor in the bottom side to keep it away from any components that might get hot and also placed some isolation slots for the same reason.
You should check-out revB of this board, I made some improvements present in the video below.