PDM support for I2S

[thiswillbeyourgithub]

All the text below is now irrelevant because of @Lana-chan 's PR. I'm now trying to merge it with @jeffmer 's GPIO commit. To keep track of the changes go to my fork

Hi,

So I made this draft PR to keep track and report on what I tried to get a recent micropython driver for the twatch V3 that supports PDM.

The idea came from this message from @devnoname120 where he mentions this repo by @lemariva which states:

This repository adds I2S support to MicroPython for the ESP32 family. The code was taken from the PR, and was updated and modified to include the I2S-PDM mode. This mode is required by some MEMS microphones e.g. SPM1423.

I first tried to build and flash the most recent micropython using @jeffmer 's commit for GPIO_WAKEUP.

Building the recent micropython

Steps I took to build and flash the recent micropython with GPIO_WAKEUP:
(The instructions to build then compile were from this README)

1. git clone -b v5.0.2 --recursive https://github.com/espressif/esp-idf.git
2. cd esp-idf && git checkout v5.0.2 && git submodule update --init --recursive && ./install.sh && source export.sh
   Note: I think all of this has to happen in the same terminal window because the esp-idf export.sh changes some PATH needed for the make command
3. cd .. && git clone https://github.com/jeffmer/micropython/
4. cd micropython && make -C mpy-cross && cd ports/esp32 && make submodules && make BOARD=ESP32_GENERIC BOARD_VARIANT=SPIRAM
5. python -m esptool --port /dev/ttyACM0 erase_flash
6. To flash using the commands from esp-idf you can use the command given as a final output from the make command. (something like /home/USER/.espressif/python_env/idf5.0_py3.10_env/bin/python ../../../esp-idf/components/esptool_py/esptool/esptool.py -p /dev/ttyACM0 -b 460800 --before default_reset --after hard_reset --chip esp32 write_flash --flash_mode dio --flash_size 4MB --flash_freq 40m 0x1000 build-ESP32_GENERIC-SPIRAM/bootloader/bootloader.bin 0x8000 build-ESP32_GENERIC-SPIRAM/partition_table/partition-table.bin 0x10000 build-ESP32_GENERIC-SPIRAM/micropython.bin). I think you can alternatively use python -m esptool --port /dev/ttyACM0 --chip esp32 write_flash -z 0x1000 build-ESP32_GENERIC-SPIRAM/firmware.bin
7. cd .. && git clone https://github.com/jeffmer/TTGO-T-watch-2020-Micropython-OS/ && cd TTGO-T-watch-2020-Micropython-OS/src
8. modify the path to mpy-cross in compile.sh to point to the one built in the micropython folder
9. ./compile.sh
10. ./install.sh

This was succesful and produced a build that flashed without issues on my V3 watch.

Now, to get the commit from @lemariva working without knowing any C I had to do some modifications to the commit code. As I don't know C I don't really know if some of my changes invalidated the commit or not but I got it flashing and booting as normal.

Trying to add PDM support

There are 4 files in @lemariva's commit:

modmachine.h

• I added all the missing lines from the commit to the micropython branch. That amounted to:

  +extern const mp_obj_type_t machine_hw_i2s_type;
  +extern const mp_obj_type_t machine_timer_type;
  +extern const mp_obj_type_t machine_wdt_type;
  +extern const mp_obj_type_t machine_pin_type;
  +extern const mp_obj_type_t machine_adc_type;
  +extern const mp_obj_type_t machine_pwm_type;
  +extern const mp_obj_type_t machine_hw_i2c_type;
  +extern const mp_obj_type_t machine_hw_spi_type;
  +extern const mp_obj_type_t machine_uart_type;
  +extern const mp_obj_type_t machine_rtc_type;
  

modmachine.c

• I needed to add + { MP_ROM_QSTR(MP_QSTR_I2S), MP_ROM_PTR(&machine_hw_i2s_type) }, \ in the section wake abilities but I ran into some issues so I ended up moving typedef enum and a declaration of is_soft_reset just a bit higher in the code.

Makefile

• apparently I needed to add a line to make sure that make would compile machine_i2s.c but the Makefile changed at lot between the recent micropython and the one for @lemariva so I ended up ignoring this step as I think the Makefile was using a glob to compile all *.c files. Given that I add compiling issue in machine_i2s.c I think this was true.

machine_i2s.c

• so apparently this file did not exist in micropython at the time of lemariva so at the time I just needed to add it directly. But now there is a machine_i2s.c file in micropython so I needed to somehow merge the changes.

• What I did was paste the whole machine_i2s.c file from lemariva at the end of the recent one, try to compile then make sense of the errors.

• I also added at the top some #include statements.

The first change was fixed by @DonvdH in this message
* The first notable change was that in lemariva there is a line:

STATIC machine_hw_i2s_obj_t machine_hw_i2s_obj[I2S_NUM_MAX] = {
        [0].used = false,
        [1].used = false };

that returned error:

/home/USER/twatch_microphone/jeffmer_micropython/ports/esp32/machine_i2s.c:510:48: error: 'I2S_NUM_MAX' undeclared here (not
 in a function); did you mean 'I2S_NUM_1'?

So I changed I2S_NUM_MAX to I2S_NUM_1 and got:

In file included from /home/USER/twatch_microphone/jeffmer_micropython/extmod/machine_i2s.c:128:
/home/USER/twatch_microphone/jeffmer_micropython/ports/esp32/machine_i2s.c:512:10: error: array index in initializer exceeds
 array bounds                                                                                                                        512 |         [1].used = false };                                                                                                      |          ^

So I tried I2S_NUM_0 and got the same.
Finally tried with I2S_NUM_AUTO and got it passed that line.
I have no idea what I'm doing.

• The second most notable change was that at the end of the file, lemariva ended up with:

const mp_obj_type_t machine_hw_i2s_type = {
{ &mp_type_type },
.name = MP_QSTR_I2S,
.print = machine_hw_i2s_print,
.make_new = machine_hw_i2s_make_new,
.locals_dict = (mp_obj_dict_t *) &machine_hw_i2s_locals_dict,
};

which returned errors like error: 'mp_obj_type_t' {aka 'const struct _mp_obj_type_t'} has no member named 'locals_dict' also for .make_new and .print.
Noticing that the end of machine_i2c.c ended up with a similar looking bunch of lines I intuitively merged it to:

MP_DEFINE_CONST_OBJ_TYPE(
machine_hw_i2s_type,
MP_QSTR_I2S,
MP_TYPE_FLAG_NONE,
make_new, machine_hw_i2s_make_new,
print, machine_hw_i2s_print,
locals_dict, (mp_obj_dict_t *) &machine_hw_i2s_locals_dict
);

which produced a build that apparently worked and successfuly built.

I think it was successful in the sense that it resulted in a flashable build, but I got many warnings and no errors, but all from machine_i2s. Here are the warnigs I got:

twatch_microphone/jeffmer_micropython/py/mpstate.h:35,
             from /home/USER/twatch_microphone/jeffmer_micropython/py/runtime.h:29,
             from /home/USER/twatch_microphone/jeffmer_micropython/extmod/machine_i2s.c:28:
/home/USER/twatch_microphone/jeffmer_micropython/ports/esp32/machine_i2s.c:770:63: warning: initialization of 'void * (*)(size_t,  void * const*, mp_map_t *)' {aka 'void * (*)(unsigned int,  void * const*, struct _mp_map_t *)'} from incompatible pointer type 'void * (*)(mp_uint_t,  void * const*, mp_map_t *)' {aka 'void * (*)(long unsigned int,  void * const*, struct _mp_map_t *)'} [-Wincompatible-pointer-types]
  770 | STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_hw_i2s_init_obj, 1, machine_hw_i2s_init);
      |                                                               ^~~~~~~~~~~~~~~~~~~
/home/USER/twatch_microphone/jeffmer_micropython/py/obj.h:391:104: note: in definition of macro 'MP_DEFINE_CONST_FUN_OBJ_KW'
  391 |     {{&mp_type_fun_builtin_var}, MP_OBJ_FUN_MAKE_SIG(n_args_min, MP_OBJ_FUN_ARGS_MAX, true), .fun.kw = fun_name}
      |                                                                                                        ^~~~~~~~
/home/USER/twatch_microphone/jeffmer_micropython/ports/esp32/machine_i2s.c:770:63: note: (near initialization for 'machine_hw_i2s_init_obj.fun.kw')
  770 | STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_hw_i2s_init_obj, 1, machine_hw_i2s_init);
      |                                                               ^~~~~~~~~~~~~~~~~~~
/home/USER/twatch_microphone/jeffmer_micropython/py/obj.h:391:104: note: in definition of macro 'MP_DEFINE_CONST_FUN_OBJ_KW'
  391 |     {{&mp_type_fun_builtin_var}, MP_OBJ_FUN_MAKE_SIG(n_args_min, MP_OBJ_FUN_ARGS_MAX, true), .fun.kw = fun_name}
      |                                                                                                        ^~~~~~~~
In file included from /home/USER/twatch_microphone/jeffmer_micropython/extmod/machine_i2s.c:128:
/home/USER/twatch_microphone/jeffmer_micropython/ports/esp32/machine_i2s.c: In function 'machine_hw_i2s_readinto':
/home/USER/twatch_microphone/jeffmer_micropython/ports/esp32/machine_i2s.c:800:66: warning: passing argument 4 of 'i2s_read' from incompatible pointer type [-Wincompatible-pointer-types]
  800 |     esp_err_t ret = i2s_read(self->id, bufinfo.buf, bufinfo.len, &num_bytes_read, timeout_in_ticks);
      |                                                                  ^~~~~~~~~~~~~~~
      |                                                                  |
      |                                                                  uint32_t * {aka long unsigned int *}
In file included from /home/USER/twatch_microphone/jeffmer_micropython/ports/esp32/mpconfigport.h:12,
                 from /home/USER/twatch_microphone/jeffmer_micropython/py/mpconfig.h:91,
                 from /home/USER/twatch_microphone/jeffmer_micropython/py/mpstate.h:31,
                 from /home/USER/twatch_microphone/jeffmer_micropython/py/runtime.h:29,
                 from /home/USER/twatch_microphone/jeffmer_micropython/extmod/machine_i2s.c:28:
/home/USER/twatch_microphone/esp-idf/components/driver/deprecated/driver/i2s.h:208:73: note: expected 'size_t *' {aka 'unsigned int *'} but argument is of type 'uint32_t *' {aka 'long unsigned int *'}
  208 | esp_err_t i2s_read(i2s_port_t i2s_num, void *dest, size_t size, size_t *bytes_read, TickType_t ticks_to_wait);
      |                                                                 ~~~~~~~~^~~~~~~~~~
In file included from /home/USER/twatch_microphone/jeffmer_micropython/py/mpstate.h:35,
                 from /home/USER/twatch_microphone/jeffmer_micropython/py/runtime.h:29,
                 from /home/USER/twatch_microphone/jeffmer_micropython/extmod/machine_i2s.c:28:
/home/USER/twatch_microphone/jeffmer_micropython/ports/esp32/machine_i2s.c: At top level:
/home/USER/twatch_microphone/jeffmer_micropython/ports/esp32/machine_i2s.c:815:67: warning: initialization of 'void * (*)(size_t,  void * const*, mp_map_t *)' {aka 'void * (*)(unsigned int,  void * const*, struct _mp_map_t *)'} from incompatible pointer type 'void * (*)(mp_uint_t,  void * const*, mp_map_t *)' {aka 'void * (*)(long unsigned int,  void * const*, struct _mp_map_t *)'} [-Wincompatible-pointer-types]
  815 | STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_hw_i2s_readinto_obj, 2, machine_hw_i2s_readinto);
      |                                                                   ^~~~~~~~~~~~~~~~~~~~~~~
/home/USER/twatch_microphone/jeffmer_micropython/py/obj.h:391:104: note: in definition of macro 'MP_DEFINE_CONST_FUN_OBJ_KW'
  391 |     {{&mp_type_fun_builtin_var}, MP_OBJ_FUN_MAKE_SIG(n_args_min, MP_OBJ_FUN_ARGS_MAX, true), .fun.kw = fun_name}
      |                                                                                                        ^~~~~~~~
/home/USER/twatch_microphone/jeffmer_micropython/ports/esp32/machine_i2s.c:815:67: note: (near initialization for 'machine_hw_i2s_readinto_obj.fun.kw')
  815 | STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_hw_i2s_readinto_obj, 2, machine_hw_i2s_readinto);
      |                                                                   ^~~~~~~~~~~~~~~~~~~~~~~
/home/USER/twatch_microphone/jeffmer_micropython/py/obj.h:391:104: note: in definition of macro 'MP_DEFINE_CONST_FUN_OBJ_KW'
  391 |     {{&mp_type_fun_builtin_var}, MP_OBJ_FUN_MAKE_SIG(n_args_min, MP_OBJ_FUN_ARGS_MAX, true), .fun.kw = fun_name}
      |                                                                                                        ^~~~~~~~
In file included from /home/USER/twatch_microphone/jeffmer_micropython/extmod/machine_i2s.c:128:
/home/USER/twatch_microphone/jeffmer_micropython/ports/esp32/machine_i2s.c: In function 'machine_hw_i2s_write':
/home/USER/twatch_microphone/jeffmer_micropython/ports/esp32/machine_i2s.c:845:67: warning: passing argument 4 of 'i2s_write' from incompatible pointer type [-Wincompatible-pointer-types]
  845 |     esp_err_t ret = i2s_write(self->id, bufinfo.buf, bufinfo.len, &num_bytes_written, timeout_in_ticks);
      |                                                                   ^~~~~~~~~~~~~~~~~~
      |                                                                   |
      |                                                                   uint32_t * {aka long unsigned int *}
In file included from /home/USER/twatch_microphone/jeffmer_micropython/ports/esp32/mpconfigport.h:12,
                 from /home/USER/twatch_microphone/jeffmer_micropython/py/mpconfig.h:91,
                 from /home/USER/twatch_microphone/jeffmer_micropython/py/mpstate.h:31,
                 from /home/USER/twatch_microphone/jeffmer_micropython/py/runtime.h:29,
                 from /home/USER/twatch_microphone/jeffmer_micropython/extmod/machine_i2s.c:28:
/home/USER/twatch_microphone/esp-idf/components/driver/deprecated/driver/i2s.h:155:79: note: expected 'size_t *' {aka 'unsigned int *'} but argument is of type 'uint32_t *' {aka 'long unsigned int *'}
  155 | esp_err_t i2s_write(i2s_port_t i2s_num, const void *src, size_t size, size_t *bytes_written, TickType_t ticks_to_wait);
      |                                                                       ~~~~~~~~^~~~~~~~~~~~~
In file included from /home/USER/twatch_microphone/jeffmer_micropython/py/mpstate.h:35,
                 from /home/USER/twatch_microphone/jeffmer_micropython/py/runtime.h:29,
                 from /home/USER/twatch_microphone/jeffmer_micropython/extmod/machine_i2s.c:28:
/home/USER/twatch_microphone/jeffmer_micropython/ports/esp32/machine_i2s.c: At top level:
/home/USER/twatch_microphone/jeffmer_micropython/ports/esp32/machine_i2s.c:860:64: warning: initialization of 'void * (*)(size_t,  void * const*, mp_map_t *)' {aka 'void * (*)(unsigned int,  void * const*, struct _mp_map_t *)'} from incompatible pointer type 'void * (*)(mp_uint_t,  void * const*, mp_map_t *)' {aka 'void * (*)(long unsigned int,  void * const*, struct _mp_map_t *)'} [-Wincompatible-pointer-types]
  860 | STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_hw_i2s_write_obj, 2, machine_hw_i2s_write);
      |                                                                ^~~~~~~~~~~~~~~~~~~~
/home/USER/twatch_microphone/jeffmer_micropython/py/obj.h:391:104: note: in definition of macro 'MP_DEFINE_CONST_FUN_OBJ_KW'
  391 |     {{&mp_type_fun_builtin_var}, MP_OBJ_FUN_MAKE_SIG(n_args_min, MP_OBJ_FUN_ARGS_MAX, true), .fun.kw = fun_name}
      |                                                                                                        ^~~~~~~~
/home/USER/twatch_microphone/jeffmer_micropython/ports/esp32/machine_i2s.c:860:64: note: (near initialization for 'machine_hw_i2s_write_obj.fun.kw')
  860 | STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_hw_i2s_write_obj, 2, machine_hw_i2s_write);
      |                                                                ^~~~~~~~~~~~~~~~~~~~
/home/USER/twatch_microphone/jeffmer_micropython/py/obj.h:391:104: note: in definition of macro 'MP_DEFINE_CONST_FUN_OBJ_KW'
  391 |     {{&mp_type_fun_builtin_var}, MP_OBJ_FUN_MAKE_SIG(n_args_min, MP_OBJ_FUN_ARGS_MAX, true), .fun.kw = fun_name}
      |                                                                                                        ^~~~~~~~

At the end of all this I flashed the whole thing using the above commands and the watch booted successfuly. But now what? when doing from machine import I2S ; dir(I2S) I don't see a PDM mode, but I don't if that's expected or not. Basically I don't know if my commit was working or not, if it did change the build, if it added functionnality or not etc.

Please help

• Can anyone tell me if the build appeared succesful?
• Were my modification to micropython sane or did I botch it? I have a feeling that my merging of the machine_i2s.c files was a problem.
• If my modifications worked, how should I test it? Reminder: my goal is to be able to record sounds on my watch.

[thiswillbeyourgithub]

All the text above is now irrelevant because of @Lana-chan 's micropython#14176. I'm now trying to merge it with @jeffmer 's GPIO commit. To keep track of the changes go to my fork