Voltlog #257 – ESP32 PIR Motion Sensor With Deep Sleep & MQTT (revB part2)

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.

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.

Voltlog #230 – Guidelines For Board Level Temperature Sensor Layout & Placement

Welcome to a new Voltlog, today I’m gonna show you some techniques that you can use when doing temperature measurements. Typically you will want to measure either the ambient temperature or the system or component temperature. Depending on one of these goals you are going to follow different design rules to achieve that. And to better illustrate the problems, I have these 3 pcbs which have exactly the same electrical circuit but with different layouts on the pcb.

The boards consist of an esp8266 and a digital temperature sensor and you might expect that since all 3 boards are placed so close together, they should all indicate the same temperature but that is not the case as we can see on this graph we are getting 3 different temperatures and only one of them is close to the actual ambient temperature measured with another thermometer, so why is that happening? Well the answer lies in the layout of the PCB and that includes component placement, copper planes and various other elements on the PCB.

Voltlog #150 – Quick Update

Welcome to a new voltlog, in this video I’m gonna give you guys a few updates on what’s going on. So I’ve been working on the bigclown review, I’ve built my project which is collecting data and I am visualizing the data with Grafana which is very nice but I’m gonna wait a few more days before I collect more data and then I’m going to release my review of the bigclown kit.

Voltlog #149 – BigClown Premium Multi Kit Unboxing

Welcome to a new voltlog, today we are doing an unboxing of the BigClown multi kit which comes in this rather interesting red clown suitcase. I’ve tweeted a photo about this and said that it’s one of the more interesting packaging methods I’ve seen in a while, it just looks good and it’s original.

→Checkout their Indiegogo campaign here.

→Checkout their online shop here.


Voltlog #40 – InTheMail

Once again too many mail items to fit into a single video, so we have a two parts upload. In the first video I only had time to show two items the SONOFF from ITead and the SP mini from Broadlink but that is including teardowns and discussions on the internals.  Surprisingly the SP mini doesn’t use the ESP8266 as expected but instead it uses the MT7681 from MediaTek.