Browse over 10,000 Electronics Projects using the Page Numbering provided at the bottom of each Page.
Ultrasonic Anemometer Part 28: New hardware tested
I last time proudly presented the new RevB board and got a lot of feedback from people who want one, too. As mentioned I have all the components here to ship up to 10 kits but I was reluctant to send anything until I had the chance to do some hardware testing. Not much had changed since the last revision but I don’t like taking chances on things like this.
In the mean time I managed to do some rudimentary testing and now feel confident to take orders. These tests concern the hardware only. What I said last time about the state of the software still applies. But let me tell you what I’ve been able to test so far.
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 [email protected] (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.
The following has not been tested so far
For my tests I still used the transducers already used previously. I believe the ones I ordered last week are of the same type but I haven’t tested them.
EEPROM. I haven’t tried the newly added memory yet. I have confirmed that it has power and is connected to the same bus as the digipot so I have no reasons to assume there are issues with it. But testing it would require some software first.
The external SPI bus has never been tested, neither on the Rev A board nor with the new one. I don’t expect any problems but I haven’t done any testing so far.
Is there anything important that I forgot to mention? In that case just ask. A lot still needs to be done but at this point I’m confident that the board has no major flaws and performs much like the prototype. Want to give it a try? I have some kits left for you.