I have a SIM800L based data logging unit. This is part of a LilyGo T-Call 1.4 unit with an ESP32 controller. I wanted to find the location of the device using the GSM network and this post gives information relating to my attempts at doing this. Spoiler alert – you cannot easily get longitude and … more
This page covers the design of a unit to monitor an anemometer (wind speed sensor) and also a wind vane (for wind direction). … more
This post covers the design of a low-cost solar irradiance sensor. This type of sensor is called a ‘pyranometer‘, (from the Greek “pyr” (fire) and “ano” (sky/heaven)) and there are a wide range of units available, typically very expensive, but accurate! I wanted to design a lower cost unit which can be easily interfaced with … more
I had obtained three samples of a DDM18SD DIN rail mounted energy meter unit. I got mine from a UK supplier on eBay, but they are available here at AliExpress and in many different places. The unit I obtained was a single phase unit for directly measuring up to 5A and 240V AC, but up … more
I’ve had a low cost carbon dioxide (CO2) sensor sitting on my desk for over a year! I thought why not get this thing recording, as I have already done a load of work sending data to MQTT feeds. The CO2 sensor I purchased was the MH-Z14A. The datasheet is available here. I did a … more
I wanted to produce a small display for simple items of data streamed/taken from the internet. My initial plan was to look at environmental monitoring, but this was Feb 2020 and covid-19 hit the UK about this time. I saw that the UK government were making the cases data publicly available & so I set … more
This post covers making an E-Paper display to show me the daily weather forecast. Obviously I can just use my phone to do this, but I wanted a free standing, battery powered display to show me this info quickly and easily. E-Paper is perfect as I can just get this info every few hours and … more
I picked up a really nice and low priced E-Paper display, called the TTGO E-Paper Series. Mine is the T5 V2.3, which uses a 2.13″ E-Paper display, has an SD card slot, a bit of flash memory, one I/O button and some clever power management ICs. It uses the ESP-32 WiFi System on a Chip … more
I have built an environmental monitoring unit for my workshop. This measures: Air Temperature, Humidity & Pressure PM2.5 and PM10 Particulate values Radiation levels It shows the data on a small OLED screen. There is a large LED RGB display which changes colour if data goes above warning levels. This unit sends data to AdafruitIO via MQTT messages. This … more
We worked recently with our friends at T4 Sustainability to produce some Raspberry Pi breakout boards for their Open Source Building Energy Management System (oBeMS) project. … more
The Latrine Logger was developed for Water For People. Water For People is an international non-profit working across 9 countries to bring safe water and sanitation to 4 million people. Water for People want to see communities break free from the cycle of poverty and spend time growing, learning, and thriving, instead of walking for … more
Monitoring the rotational speed of the wind turbine blades can help with power performance measurements. This post shows various techniques to measure the rotational speed of a ‘wild AC’ output small wind turbine. In this system, the wild AC is rectified into DC and either delivered to a battery or to a grid-connected inverter. The … more