Audio kit V2.2 ES8388: schematics for the USB host pcb

[heyudude]

I am starting my journey to enable the Audio kit and the USB host SPI interface to communicate to my USB MIDI keyboard.
I saw a dozen of video's already (thanks for all your efforts) but I am a bit lost in connecting the USB host PCB based on the MAX3421E to the ISP interface on the Audio kit. I know about the hardware modification, that will the first challenge to solder those tiny parts ;)

Can someone direct me to the USB host PCB connections overview to the Audio kit?
Is there a summary of all the steps to undertake in order to get the chain of hardware working?

[marcel-licence]

In https://github.com/marcel-licence/esp32_usb_midi there are 4 lines required for data (CS, SCK, MISO, MOSI). In addition to that 3V and GND connection is required. To supply a connected device an additional 5V supply needs to be attached to the USB breakout. I just connected it with jumper wires.

A little schematic is included in the video: https://youtu.be/Mt3rT-SVZww?t=56

Do you need some specific information? I would recommend to try the esp32 usb midi project first. You can use the serial monitor to check its operation

[marcel-licence]

Thank you, Happy Easter!

You should find also a backtrace. There is a mechanism where you can open the ESP32 Exception tool. It should be available by default. It will open a window where you can paste in the backtrace. After doing that it will show you the last current call stack before the reboot was initiated. That often helps to identify problems.

[marcel-licence]

Does this show the correct setup now?

[heyudude]

Stack decoded:
PC: 0x40091adc
EXCVADDR: 0xffffffff

Decoding stack results
0x400e129c: uart_read_bytes at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/driver/uart.c line 1315
0x400da125: uartRead at /Users/dude/Library/Arduino15/packages/esp32/hardware/esp32/2.0.3-RC1/cores/esp32/esp32-hal-uart.c line 260
0x400da77d: HardwareSerial::read() at /Users/dude/Library/Arduino15/packages/esp32/hardware/esp32/2.0.3-RC1/cores/esp32/HardwareSerial.cpp line 420
0x400d3b5d: Midi_CheckMidiPort(midi_port_s*) at /Users/dude/Documents/Arduino/esp32_basic_synth/midi_interface.ino line 359
0x400d416c: loop() at /Users/dude/Documents/Arduino/esp32_basic_synth/midi_interface.ino line 434
0x400db335: loopTask(void*) at /Users/dude/Library/Arduino15/packages/esp32/hardware/esp32/2.0.3-RC1/cores/esp32/main.cpp line 50

and this compiler error:
[Wire.cpp:313] beginTransmission(): Unfinished Repeated Start transaction! Expected requestFrom, not beginTransmission!
I just used git clone again to start fresh

[heyudude]

The mapping of the 4 lines from host to audio kit (no time yet to check what labels they have) this gives a correct midi dump codes

[marcel-licence]

I guess there is a pin conflict, means that you try to use the same PIN for different interfaces: SPI, I2C and UART/Serial.
You are using the USB interface so you could remove the Midi_Process call in your loop function. The cleaner solution would be to look up which MIDI_RX1_PIN, MIDI_RX2_PIN is defined by the included board header and remove the definition.
You can do that by adding
#undef MIDI_RX1_PIN
#undef MIDI_RX2_PIN
to your config.h

[heyudude]

Thanks that was the path to the next stable situation. no reboots: going to test the midi setup and see if I get some sound out of it :)

I used the Undef at the end of the config.h and remove the loop as directed.

[marcel-licence]

Sounds great. Usually I expect that you can keep the call in the loop. The undef should be the only required change to turn of the serial MIDI ports. Thank you for your feedback

[heyudude]

Went back tot the ESP32 setup
So the DAC works, a few seconds.
5 tones sometimes more or less then it is silent. Could be the different pcb that is causing this?
It needs 5v and gnd and 3 lines
Sck is not used

[marcel-licence]

The top row of your DAC might also require some proper connections. You can find some pinouts on the internet. There is also one pin for mute. I am not sure if some static charge might cause random behaviour.

[heyudude]

Thanks. On all the discussions on this purple board I only see the small row connected. This page (although not related to synths) provides more insights, http://tomeko.net/projects/esp32_rtp_pager/

It has 4 solder pads to enable some functions. I made it work on the esp32 with some internet radio code. Works great.

I expect that the soft mute is enabled somehow. I try this evening.

[marcel-licence]

I have 1, 2, 4 connected to GND and XSMT should be pulled up. I observed also random issues when pins are floating.

[heyudude]

I know, this board is different and also in how it should be coded / and maybe the library .
I try to get it going until the same as you have arrives. That is for sure compatible
My purple one works great with another es8388 library as internet / wifi radio, but no synth sounds for a long time
thanks for helping me

[marcel-licence]

The purple one contains the PCM5102a. The ES8388 is another codec which uses I2S for audio and I2C for configuration. The PCM5102a does not need any configuration and does not have any I2C interface which makes it usability a bit easier. Hope this information helps.