ES8388 I2S pins wrong on A247 revision (plus addtional mods for larger screen and rotary encoder)

[benwaterson]

Been trying to get basic sounds out for a few days and tried the different config options in board_audio_kit_es388.h

Found another github page with definitions and it appears the DOUT and DIN pins are backwards

https://github.com/pschatzmann/arduino-audiokit/wiki/GPIO-Overview-by-Selected-Board

was previously

#define ES8388_PIN_DOUT 35
#define ES8388_PIN_DIN 26

Made a new option num 6 and now getting sound with them switched around.

/* reversed dout/din */
#define ES8388_PIN_DOUT 26
#define ES8388_PIN_DIN 35
#define ES8388_PIN_LRCK 25
#define ES8388_PIN_SCLK 27
#define ES8388_PIN_MCLK 0

[marcel-licence]

Thank you very much for sharing. Did you get audio input and output successfully working?

I've prepared the change in a branch: https://github.com/marcel-licence/ML_SynthTools/blob/Branch_discussion_37_I2S_A247/src/boards/board_audio_kit_es8388.h

[marcel-licence]

I've looked at the linked table. I think swapping the pins will not work. It depends if you say it is the ESP32 pin 35 is DOUT or the pin 35 of the ESP32 should be connected to DOUT of the audio codec.
It is like connecting tx to rx.
The names I am using is seen from ESP32 side. So DIN is used to receive data and DOUT is to send data to the audio codec. Hope this helps.

[benwaterson]

Yes, the config provided works perfectly for me (no sound otherwise)

#define ES8388_PIN_DOUT 26
#define ES8388_PIN_DIN 35

I understand how it could be confused (depending which chip inside it refers to in/out), all I know is it just comes out as noise otherwise.

[benwaterson]

I have also done the analog button mod, so running an ILI9341 240x320 screen on it now (modded the display code to support it) and also have a PCF8574 running on pins 19/22 to give me 8 more I/O as I am going to convert the menus to use a rotary encoder or two. This is because I want to mount the board into an AE Modular synth and the buttons are too fiddly.

Also, as a bonus I am running an FTP server as well so I can upload samples directly to a 32GB sd card - works nicely (uses code from here https://github.com/fa1ke5/ESP32_FTPServer_SD_MMC)

[benwaterson]

TFT (this one http://www.lcdwiki.com/2.8inch_SPI_Module_ILI9341_SKU:MSP2807)

#define TFT_MOSI 23
#define TFT_MISO -1 // not used as don't read back from screen
#define TFT_CLK 18
#define TFT_CS -1 // tie to GND on TFT
#define MCP_CS 5
#define TFT_RST -1 // Connected directly to ESP32 Audio Kit RESET pin
#define TFT_DC 21 //12 is for SD usally, 21 (not 0, as conflicts with ES8388_PIN_MCLK)
#define TFT_BLK_PIN -1 // not used

// this frees up IO 19 and 22 for additional I2C

Code mods include :
#include <Adafruit_GFX.h> /* requires library Adafruit-GFX-Library from https://github.com/adafruit/Adafruit-GFX-Library */
#include <Adafruit_ILI9341.h> // Hardware-specific library for ILI9341 from here https://github.com/adafruit/Adafruit_ILI9341

And referenced like this:

static Adafruit_ILI9341 tft = Adafruit_ILI9341(&DispSpi, TFT_DC, TFT_CS, TFT_RST);

And switched the colour names to the equivalent such as ILI9341_BLACK

I also inverted the colours so white text on a black background, as easier to read.

For the IO Expander:

PCF8574 SPI (using library here https://github.com/RobTillaart/rotaryDecoderSwitch)
SDA on 19
SCL on 22

// had to remove LED refs that use these pins

Had to modify the example code slightly to use Wire1 (instead of Wire) else it conflicts with the ES8388 I2C

[benwaterson]

[benwaterson]

I have updated the title of this item to reflect the other mods above. (for anyone else interested in adding more hardware)

[marcel-licence]

Hi that looks nice!
Does the rotary encoder use other wires than the ES8388? I would expect to be able to use one Wire SDA/SCL for multiple devices.
That's weird that DIN and DOUT are swapped. Do you use the unmodified audio driver?
The ILI9341 is a nice addition!
Thank you very much for sharing

[benwaterson]

I am using pins 19 and 22 for secondary I2C so i can put multiple devices on that bus.

Rotary encoder uses 3 pins (as it also has a push switch) and they go to the PCF8574 (I have 5 of these boards which can be plugged into each other and set to different I2C addresses to expand the I/O, 8 bits at a time)

Now I have secondary I2C I am adding DAC (mcp4728) and ADC (ADS1115) boards so I can interface with my AE Modular synth using CV. Will level shift the I2C bus from 3.3v to 5v (bi-directional) so I can run 5v signals into I2C (as esp32 is not 5v tolerant).

DAC and ADC are both 4 channel, so should give me enough i/o to do something interesting (https://www.tangiblewaves.com/diy-info.html) - hopefully there isn't too much overhead on I2C to cause sound issues.

I did try some ESP32 overclocking code, however it breaks the wifi so would need more investigation (as it affects all timing on the board) - https://github.com/markbirss/SIMPLE-ESP32-OVERCLOCK-EXPERIMENT

[marcel-licence]

Do you need a second I2C bus? I thought that attaching all devices to one bus should work in case there are driven from just one core.
Would the level shifter allow connecting 5V devices to a bus with 3.3V devices already attached?
I don't know if the I2C is fast and uses DMA within Arduino. I would be happy to hear about your experience.

I never tested overclocking.

[benwaterson]

Isn't the other I2C bus internal to the ESP32-A1S (connects under the EMF shield)? Either way, what I have set up now works.

#define ES8388_PIN_SDA 33
#define ES8388_PIN_SCL 32

I don't see those I/O exposed on the schematic?

All of the devices I will connect to the new I2C bus will run on 5v (including the rotary encoder(s)), so best to keep them all that way as the AE Modular synth system is purely 0-5v system.

In theory you should be able to mix and match, putting them either side of the txs0108 level shifter I will be using. Will report back when I have wired more parts up.

[benwaterson]

I then need to try and it it all in to this space....

[benwaterson]

Ok after some troubleshooting with the oscilloscope, I have the level converter and ADC set up and hooked the esp32 etc into the 5v power rail on the modular system. esp32 sees both i2c devices fine now (io expander and adc)

A quick test of one of the ADC channels is reading fine from the output of the envelope generator in the modular.

I am currently running in the Core 1 100hz loop, may experiment in the Core 0 task though - depends on how smooth i need the ADC values (once I work out what I am going to do with them :) ) - initial thought are to get the pitch/gate voltages to control sampler/synth engines in the ESP32. Pitch is 1V/Octave.

void loop_100Hz(void) {
static uint32_t loop_cnt;

loop_cnt += 1;
if ((loop_cnt) >= 100) {
loop_cnt = 0;
loop_1Hz();
}

/*
* Put your functions here which should be called 100 times a second
*/
#ifdef ESP32_AUDIO_KIT
button_loop();
decoderloop(); // get pcf8475 rotary encoder vals
adsloop(); // get ADC values
#endif
}

[benwaterson]

Update to confirm that ADC polling works far better if it's set to run inside the Core0TaskLoop - seriously affects audio playback otherwise

[marcel-licence]

Sounds reasonable. I observed similar issues and decided to run the audio core alone to avoid any interrupts. The ADC didn't provide the best signal that causes some more delays by having some kind of oversampling. Do you use internal ADCs of the ESP32 or just the external via I2C?