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

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

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

Arduino and LED Matrix Display

I was asked to build a BIG LED display for a pedal powered cinema for a film group in Brussels (more about that in another post). I found these huge displays from Embedded Adventures and had wanted an excuse to have a play with one of them for a while. This is a post about … more

Arduino and Mobile Data

I’ve been wanting to play around with sending data via a mobile SIM card and, after needing to do it for another project, here is a short post on my attempts at getting it all going. I used an off the shelf GSM/GPRS module (the SIM900). I tried this using both the Arduino Uno and … more

8 x 32 LED display unit

I’ve been messing around with some 32 x 8 LED displays – as I have been wanting to create graphics. These LED displays are from Sure Electronics are available for around $13 and use the HT1632 LED driver IC, with an SPI-like control. I have previously used these displays for a couple of projects here … more

Minimus, Arduino IDE and USB

I have mentioned the Minimus AVR before on this blog. It is a very low-cost ATMEL micrcontroller board with a USB bootloader. This post describes using the device as a HID (Human Interface Device) such as a keyboard or mouse. A challenge was set by a friend to take serial commands and, depending upon the … more

Humidity sensors part II

Following on from my previous post on measuring humidity, I decided to test another couple of humidity sensors I had lying around. These were the DHT11 and the DYPTH01B. These are both low-cost capacitive sensors and both had been obtained when I put in an order with a Chinese supply website (Sun Tek Store). Neither … more

Humidity sensors

For a new project I am looking at measuring weather data in remote locations. This is for a low-cost, low-power wind data logging unit. The main parameter to record is, of course, the wind speed and I am doing this with ten minute averages from a pulse-output anemometer. While this data is useful, it would … more

Sleep Modes on ATTiny85

When using microcontroller in battery-based applications we really need to look at current consumption. This will affect the power consumption and hence the lifetime of the device. This post shows some tests I performed to try and reduce the current consumption of an ATtiny85 AVR microcontroller using sleep modes and switching off various aspects of … more