Measuring strain using strain gauges.
I tested the strain indicator unit with a rosette, next step would be calibrating the readings with a commercial strain indicator at college.
The readings shown on display are just the raw voltage from the Wheatstone bridges in milli-Volts, Later I'll add the rosette as well as the linear gauges equations to calculate strain using these readings, GF (gauge factor or sensitivity) which is dependant on gauge material/type and finally the orientation and bridge configuration (Full-Bridge / Quarter-Bridge).
In my case all the channels are quarter bridges with 120 Ohm SMD resistors.
Awaiting feedback =)
I just finished soldering all of the components to the PCB and I found out I missed a track from Teensy's VIN to the VCC of the display and all I got was the backlight LED, after a little troubleshooting with the multimeter continuity mode and reviewing my designs I added a wire (the yellow one in the photos below) going from VCC to VIN and it worked!
Btw this is my 1st try with a hot air soldering station and it went great, I used it to solder the 120 Ohm SMD resistors on the board. The rest of the components were soldered using a normal iron.
Here are some photos along the way, enjoy!
Just received my PCBs from SeeedStudio Fusion PCB service, the finish and the silkscreen are great. This is my first order with them.
Here is a photo of the PCBs and next to it is the home made version (using photoresist method).