Find Location with SIM800L

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

Low-Cost DIY Solar Irradiance Sensor

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

Talking to a DDM18SD Energy Meter

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

CO2 Monitor

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

COVID Cases Monitor

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

Creating a Weather Display

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

TTGO E-Paper Display

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 2.19″ 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

Workshop Environment Monitor

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

Latrine Logger Unit

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

RPM sensor for Wind Turbine

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