And there it is!
Strangely, the toughest part of this job has not been the soldering, nor the programming (if you except the part where the transceiver did not work…) but the sewing. I did spend quite a significant amount of time trying to find the proper way to have the LEDs on the tshirt, not have them bother me when I run, be able to remove them to wash the tshirt.
Here is the result: I am using velcro to place the LEDs on the shirt, allowing me to remove them and/or reposition them whenever necessary.
Velcro is also there to secure an additional layer of fabric to hide the LEDs.
And here is the first proof of concept of the device. The display is not attached to the shirt yet, but you can see my real heart rate (a bit high, I must admit). You can see my heart rate increase as I move around a bit. Coming next: displaying speed and making the display wearable.
I can now interface properly with the Garmin sensors, and display the information on the LEDs !
The inside of the beast is complete. I have managed to cramp into an Arduino case the Arduino Uno, connectors to both the transceiver and the LEDs, as well as a 9v battery (no idea how long it will last). The LEDs and the transceiver are both getting 5v from the Arduino, allowing me to have simple power hanlding with one battery for all of it.
The aim of this project is to have my shirt display my heart rate and speed. To do this, I am planning on using the following hardware:
I have been having a hard time getting the transceiver to work: my Arduino is 5v, the transceiver 3,3v, and even with a logic level converter, it never communicated properly. I accidentally fed it 5v and realized it worked. I have no idea why, and it might decrease its life expectancy, but it will do for now…