Week 11: Input Devices
This week assignment was to add a sensor to a board and read something.
Tools
- Fabmodules: We have it already installed on a laptop at the lab. Used to send the .png traces design to the milling machine.
- Roland MDX-20 Milling Machine: To mill and cut the PCB boards.
- Soldering Iron and tin: The basic tools for soldering.
Process
As my final project requires using sensors to get data from the weather I chose to make the light(reflect) and temperature sensor examples for the assingment.I used the already known process to mill the boards, although I had a little problem while doing the final cut with the 1/16 mill: the mill didn't went though the board, using both fabmodules versions, changing depth settings, rebooting the laptop, turning on and off the Roland, etc. Nothing seemed to work, not even manually lowering the mill. After a while of struggling, it finally worked out, although I did not find any explanation behind.
Afterwards, soldering the components was no problem.
I programmed using the uploaded code (.c , .make)the light (reflect) sensor. For some reason, programming is done successfully, but when executing the python file it doesn't detect anything. I tried with the temperature sensor but I couldn't even program it.
At the point of almost remaking the sensor boards, we tried programming them with the AVRISP. It could program both without hesitation, so the problem was my FabISP back from week 4.
As I intend to use my Raspberry Pi 2 for my final project (or at least know a bit more about it) I tried to hook up the sensors to the raspberry's pins, using serial connection. Raspberry uses pin 8 for TxD (Transmit) and pin 10 for RxD (receive), pin 2 and 4 for 5v power (VCC) and several as ground.
So the connection would be the following:
TxD doesn't need to be connected as no data would be sent to the sensor (also that pin on the FTDI is not used). Raspberry only needs to read data from RxD. Plus send power over VCC and GND.