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

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

Fast PWM on ATTiny85

This is a post about changing the PWM frequency of an ATTiny85 which has been programmed via the Arduino IDE. I wanted a faster PWM frequency to remove audible noise on a dump load controller I had been designing. This controls an output load using PWM and a FET. This produced audible noise when running. … more

Charge Controller prototype

Here are a few photos of the prototype of the open charge controller project. I have recently got the second version of the PCBs and have designed a simple case for it. I’m in the process of testing all the functions and finishing off the software algorithms for it. Its based around an ATtiny85 microcontroller … more

TFT LCD display

This is a post about getting a graphical full colour LCD screen running with an Arduino. The sample screen was the ITDB02 1.8″SP unit from iTead Studios. It is based upon the ST7735 control IC which uses serial data for the display.   … more