Lukas Fassler has designed and built an Ultrasonic Anemometer project with Dirty Board PCBs.
Tests performed so far
- The PIC32 can be programmed from a PICKit3 via the ICSP header without any issues.
- Power consumption is as expected. Like the previous version it draws 45mA@12V (programmed) and the other two rails come up with +3.310 and -3.279V, respectively. Also as expected. Regulator stays cool.
- With the PIC controlling the AXIS, DIRECTION and SIGNAL pins, the transducers receive the 12V signal from the mosfet drivers. HOWEVER: the signals AXIS and DIRECTION are incorrectly labeled both in Eagle as well as on the silk screen. Electrically everything is fine but the names have been confused.
- The signal from the transducers is properly received (Rec pin on the board) and amplified by a factor of 11 by the first stage of the amplifier (S1 pin on the board).
- The PIC is able to control the digipot over the internal I2C bus and the second amplifier stage also performs as expected.
- The zero-crossing detector (ZCD) works.
- The input to the PIC’s ADC (ADC+ and ADC-) look fine, too. HOWEVER: the labeling on the silk screen is wrong. Eagle is correct, it’s just the silk screen. Plus should be minus and vice-versa. Again, electrically everything is fine.
- The PIC can communicate (as a slave) with an Arduino UNO connected to the external I2C bus.
- Communication over USB to a YAT-terminal under Win 7 works.