Sinclair C5duino - Journey Data Logger

With the C5duino control box and LCD display completed I've been looking at the possibility of recording data from the C5 whilst in use. By data I mean useful information like battery use, motor temperature changes, motor/pedal usage etc.

A primary requirement to do this is to have some sort of mass storage device attached to the system to record the data.

SD Card

Enter the SD card slot that can be found on the back of the LCD touchscreen.

The C5duino PCB plus LCD Touchscreen

This has been unused so far in my C5/Arduino projects but now I have decided to put it to good use.

One major problem trying to use the SD card is the shield PCB that sits between the screen and the Arduino Mega (made by Sainsmart). Some of the connections are wrong!

After a bit of searching and testing the connections with my multimeter it became clear 4 of the small resistors need to be removed and the connections need changing.

Out on the Road

To create some sample data I took the C5 out for a short 15 minute 2-3 mile ride with the motor on pretty much constantly apart from 2 instances where I pulled into a lay-by‎ for a few moments. The time into the ride runs along the bottom and is measured in seconds (x10).

Motor Temperature Changes Chart showing motor temperature changes

Motor Current (Amps) Chart showing motor current changes

Speed Changes Chart showing speed changes

Voltage Changes Chart showing voltage changes

The battery I used was in need of a charge, hence the sudden drop in voltage at the start in the final chart. But it's still useful to see all the above data for the journey.

On the Road Part 2

With the recent addition of a reed switch on the pedal crank we can now track how much pedalling the C5 driver is doing. Here is the data for a 26 mile, 2.5 hour drive:

Chart showing pedal/motor/coasting times on a recent trip

Chart showing pedal/motor/coasting times on a recent trip


The software to record all this data is built into the LCD touchscreen Arduino project. Any changes on any of its display data is also entered into an XML log file on the SD Card. After a trip I remove the SD card and insert it into my laptop and, with a bit of software, can convert the data into line charts.

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