ADAU1701 comms failed
Apologies in advance, I'm inexperienced. I'm following this project (relevant timestamp linked): youtu.be/XEspOD1NHr0
I've already successfully connected to one of these ADAU1701 boards and compiled a program to it. The four connected drivers play sound as expected.
The second board I programmed before connecting any drivers, and followed the same process (the first board was connected to drivers to run a channel tester project and ensure correct mapping). The compilation was successful, and writing and checking were successful.
Once the drivers were connected, I tested and found that none were receiving signal from the second board. At first I thought this was because I reversed the polarity of power sent to my amplifier (since my power source had swapped colors for positive and negative). Power was very briefly connected, I don't know if any damage occurred. I corrected that mistake, and the LED's on the amplifier, DSP, and voltage regulator all illuminate, so I expect that no damage occurred. The DSP gets power from the regulator which shares the amplifier's input power. I don't know if it's correct to say that the DSP should have been protected from damage, but it seems to be fine, other than the original issue of not getting any signal to the drivers.
I wanted to run a channel tester project on the board to see if this was an issue with the input to the board or the board itself. The input wires seem to be correct, and I used my meter to check the connections.
Now when I connect to the board, and try to compile and download, the lower status bar says "compiled, Comms Failed"
I can't find much relevant info on this and would really appreciate some help. Again, I've already compiled to this board, the only change since then was the reversed polarity. The green LED is on, I'm just not sure how to diagnose if the board is broken, or needs some kind of reset, or something else.
Audio Signal Processors
Audio Products
software
SigmaDSP Audio Processors
adau1701
Hello,
The following tests may help you trace the source of the "no sound" condition:
Obtain all the info you can from the manufacturers' Web sites for the DSP board, amplifier, and voltage regulator boards. The DSP board's manufacturer may have troubleshooting tips or a support forum where you can find help from other hobbyists using this board.
Perhaps the voltage regulator board has been damaged, as it's the first thing the reverse-polarity hit. Measure the voltage of each regulated output. Although all the various system LEDs are lit, that doesn't mean that the boards are getting their correct voltages. Typically, readings within 5% of nominal are good enough. If the voltage regulator is set up to output 5 volts to the DSP board, the board itself has a 3.3V regulator to run the -1701. Might as well find this part on your DSP board -- it usually is a rather larger part with a metal tab and three pins -- and measure its output. The tab is usually ground (zero volts). Be very careful not to short any pins together when making any on-board measurements. Such shorts cause further damage.
With the programmer connected to the suspect DSP board and your computer, and power ON, open your SigmaStudio project and view the Hardware Configuration tab as shown below. With the programmer attached, the USB block should appear green, as shown below. If it's orange, your computer is not seeing the programmer. Test the programmer by using it with your other speaker system (the one that works).
The -1701 DSP operates at 49.152 Mhz. Double this frequency (the second harmonic) is 98.304 Mhz. If you bring the antenna of a portable radio tuned to FM 98.3 Mhz. near the DSP board, you should hear some effect upon the radio. Although this signal has no audio modulation, it typically quiets the "hissing" that the radio makes without a station, or else interferes with the station on that frequency. If you hear no effect at all, the DSP may be dead.
The DSP, the programmer, and SigmaStudio perform a coordinated "dance" to load the DSP program. Any problem with the DSP or programmer stalls this operation, resulting in the "Comms Failed" error. I'm assuming that the board is equipped with an EPROM which can store and then load the -1701 upon power-up, so your speaker system can operate without a computer and programmer connected. Some manufacturers of these boards pre-program the EEPROM with a default program which simply routes all inputs to all outputs (etc.). If the first speaker system gave sound even before programming, then this one should also.
Since you have one speaker system that works, you can compare the results of any of these tests with that of the "good" system.
If all ese fails, you could disconnect the suspect DSP board from the "bad" system and substitute it into the "good" system, to see if it works there. This should definitely determine if this board is OK or has been damaged in the reverse polarity event.
Hope this helps.
Bob
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