Replies: 2 comments 15 replies
-
|
Hi, since you have your oscilloscope already at hand, I'd probably start with probing pins 1-4 of the MCP3204 to check if any signal arrives there. This should rule out any issues with the analog part. You can also try shortly bridging Vref to one of those pins and check if this does trigger a hit. Maybe also check all Vcc pins for the correct voltages while you are at it, just to be sure. The next step would be changing to 'Debug' mode and connect via serial terminal. This will show you the ADC readings if a hit is detected, so I recommend lowering the thresholds for this. (Mind that the values are mapped to 16bit and a peak will stay for the duration of 'Hold Time'). If the analog part is good and you still don't get any output in 'Debug' mode, I'd suspect an issue with the ADC or level-shifter. Further, are you using the pre-built firmware or did you build it yourself? Anyways, cool project! I'd really be interested how well this performs with an actual arcade drum. |
Beta Was this translation helpful? Give feedback.
-
|
|
Beta Was this translation helpful? Give feedback.
-
|
Hmm, that's indeed strange. I don't see any obvious problems with your board. Since none of the analog inputs seem to yield any output, can you check the +12V and -12V rails on the TLC072 opamps? Further you try to 'trace' the signal through the circuit and see where it gets lost, basically follow the horizontal path between the '*_IN' and '*_ADC' labels in the schematic. It is further weird that you can't trigger the inputs directly. Maybe try to flash the pre-built firmware from the releases page to rule out any issues with you particular build, just to be sure. |
Beta Was this translation helpful? Give feedback.
-
|
I'm getting about 13V coming out of the converter and at all the rails of the Op-Amps-- is that normal? |
Beta Was this translation helpful? Give feedback.
-
|
I'm not sure what changed, but I am definitely seeing the signals coming into those MCP3204 pins that I have attached wires. What should I do to make sure the MCP3204 is "outputting" the right signal to the U7? |
Beta Was this translation helpful? Give feedback.
-
|
Just for reference, I'm measuring +/-12.6V, +3.33V and +5.1V respectively. Slightly lower, but your measurements should still be well within tolerance. U7 does the level shifting between 3.3V and 5V for the ADC's SPI communication. Pin 8 should be a constant 3.3V, the rest of the pins should mirror the signal of the opposing pin with a different voltage. Pin 5/10 should be a clock signal, Pin 2/13 should be pulled low in regular intervals. On Pin 4/11 and 3/12 you should see some data being exchanged. |
Beta Was this translation helpful? Give feedback.
-
|
I think I've gotten further than I've been before! I have it in DEBUG mode and its outputting:
repeatedly. Not sure what this means, as I'm having a hard time parsing the USB_DEBUG code. Any ideas what might be happening? |
Beta Was this translation helpful? Give feedback.
-
|
The debug line is constructed in DonCon2040/src/utils/InputState.cpp Line 370 in 58cf743 It's meaning is as follows: Since all your ADC inputs show the maximum value constantly, I suspect there either is an issue with the inputs to the ADC, it's reference Voltage, or the SPI MISO line being high constantly. |
Beta Was this translation helpful? Give feedback.
-
|
OK, that's helpful! Thank you. (And thanks again for being so helpful and patient with my questions!) At this point, I know that SPI MISO is not being high constantly (output shown here):
It looks like the 3.3V line looks OK on the 2040. I also confirmed that I'm seeing the drum signals arrive at the MCP. I see about a 1V spike for KA and a 4V spike for DON. How do you recommend I check the inputs to the ADC? I'm assuming it's something happening between U5 and U7, but I could be wrong. |
Beta Was this translation helpful? Give feedback.
-
|
Hmm, maybe check the pin pairs 5/10 4/11 4/12 and 2/13 to see if the signals are the same on both sides of U7 (with 3.3V/5V respectively) and if they look like valid SPI (clock is running, CS goes low for transfer etc.). If so and the drum signals and the reference voltage on U5 pin 13 looks correct, I'm somewhat out of ideas ... maybe the ADC is defective |
Beta Was this translation helpful? Give feedback.
-
|
What should VRef on U5 be showing? |
Beta Was this translation helpful? Give feedback.
-
|
VRef should be very close to 4.096V |
Beta Was this translation helpful? Give feedback.
-
Alright, I've got the board all assembled and I believe it's assembled correctly. I have my drum (actually an official Namco Bandai Arcade drum, so I'm essentially trying to retrofit a real arcade setup to work with the console games). I've also connected the outputs of the piezo's to an oscilloscope and can confirm that they're working.
I have the piezos from the arcade machine connected to the board, but I'm not seeing any "hits" or presses when I connect the board. Not sure where to start debugging here, if I should just start with changing the trigger thresholds? Or if there's an easier way to figure out what's going on?
Is there a way for me to output the ADC values from the Piezo's in this setup? Looking for any help or guidance on where to start debugging.
Beta Was this translation helpful? Give feedback.
All reactions