Integration of PDM microphone with thingy53

[Rakshita]

I want to integrate the PDM microphone with thingy53, I found no particular sample code for it

Would be needing help from scratch

[ovrebekk]

Hi Rakshita

Have you tested the DMIC sample in the SDK?

It is not officially supported on the Thingy53, but it does support the nRF5340DK. If you copy and rename the nrf5340dk_nrf5340_cpuapp.overlay file to thingy53_nrf5340_cpuapp.overlay, and change the pins as necessary, I would expect the example to work on the thingy as well. 

Not sure what you mean about repeating output? If I understand you correctly the clock output from the nRF53 is fine, but the data from the microphone seems wrong? Would you be able to attach a trace/scope capture? 

Best regards
Torbjørn

[Rakshita]

dmic is not working with thingy53 even after changing the overlay files 

[ovrebekk]

Hi Rakshita

Could you try to build for thingy53_nrf5340_cpuapp instead of thingy53_nrf5340_cpuapp_ns? 

I am also struggling to get it to work when building for the non secure target. 

When building for thingy53_nrf5340_cpuapp I was able to see activity on the PDM clock line, which I routed to P0.08 so that it can be accessed from the debug and extension board. 

I have included my modified dmic example below: 

dmic_thingy53.zip

Best regards
Torbjørn

[Rakshita]

The PDM_CLK pin is at P1.09 right?

[Rakshita]

The code which you shared is not building, terminating with exit code 1

[ovrebekk]

Hi Rakshita

I set the PDM_CLK to P0.08 and the data pin to P0.09, as you can see from the overlay:

	psels = <NRF_PSEL(PDM_CLK, 0, 8)>,
		<NRF_PSEL(PDM_DIN, 0, 9)>;

Which SDK version are you using to build it? 

Can you share the full build output with me so I can try to figure out what is happening? 
Please use the Insert -> Code feature in devzone to add a larger block of text, or attach the build output as a text file. 

Best regards
Torbjørn

[Rakshita]

Yes but as per the thingy's schematic the clk pin is P1.09 and data pin is P0.27
sdk v2.5.2

[Rakshita]

Executing task: nRF Connect: Build: dmic_thingy53/build (active) 

Building dmic_thingy53
west build --build-dir c:/nrf/samples/bluetooth/dmic_thingy53/build c:/nrf/samples/bluetooth/dmic_thingy53

-- west build: generating a build system
Loading Zephyr default modules (Zephyr base (cached)).
-- Application: C:/nrf/samples/bluetooth/dmic_thingy53
-- CMake version: 3.20.5
-- Cache files will be written to: C:/ncs/v2.5.2/zephyr/.cache
-- Zephyr version: 3.4.99 (C:/ncs/v2.5.2/zephyr)
-- Found west (found suitable version "1.1.0", minimum required is "0.14.0")
-- Board: thingy53_nrf5340_cpuapp
-- Found host-tools: zephyr 0.16.1 (C:/ncs/toolchains/c57af46cb7/opt/zephyr-sdk)
-- Found toolchain: zephyr 0.16.1 (C:/ncs/toolchains/c57af46cb7/opt/zephyr-sdk)
-- Found BOARD.dts: C:/ncs/v2.5.2/zephyr/boards/arm/thingy53_nrf5340/thingy53_nrf5340_cpuapp.dts
-- Found devicetree overlay: C:/nrf/samples/bluetooth/dmic_thingy53/boards/thingy53_nrf5340_cpuapp.overlay
devicetree error: pinctrl-names property in /soc/peripheral@50000000/pdm@26000 in C:/ncs/v2.5.2/zephyr/misc/empty_file.c has 1 strings, expected 2 strings
-- In: C:/nrf/samples/bluetooth/dmic_thingy53/build/zephyr, command: C:/ncs/toolchains/c57af46cb7/opt/bin/python.exe;C:/ncs/v2.5.2/zephyr/scripts/dts/gen_defines.py;--dts;C:/nrf/samples/bluetooth/dmic_thingy53/build/zephyr/zephyr.dts.pre;--dtc-flags;'-Wno-unique_unit_address_if_enabled';--bindings-dirs;C:/ncs/v2.5.2/nrf/dts/bindings;C:/ncs/v2.5.2/zephyr/dts/bindings;--header-out;C:/nrf/samples/bluetooth/dmic_thingy53/build/zephyr/include/generated/devicetree_generated.h.new;--dts-out;C:/nrf/samples/bluetooth/dmic_thingy53/build/zephyr/zephyr.dts.new;--edt-pickle-out;C:/nrf/samples/bluetooth/dmic_thingy53/build/zephyr/edt.pickle;--vendor-prefixes;C:/ncs/v2.5.2/nrf/dts/bindings/vendor-prefixes.txt;--vendor-prefixes;C:/ncs/v2.5.2/zephyr/dts/bindings/vendor-prefixes.txt
-- Configuring incomplete, errors occurred!
CMake Error at C:/ncs/v2.5.2/zephyr/cmake/modules/dts.cmake:279 (message):
  gen_defines.py failed with return code: 1
Call Stack (most recent call first):
  C:/ncs/v2.5.2/zephyr/cmake/modules/zephyr_default.cmake:129 (include)
  C:/ncs/v2.5.2/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:66 (include)
  C:/ncs/v2.5.2/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:97 (include_boilerplate)
  CMakeLists.txt:5 (find_package)


FATAL ERROR: command exited with status 1: 'C:\ncs\toolchains\c57af46cb7\opt\bin\cmake.EXE' -DWEST_PYTHON=C:/ncs/toolchains/c57af46cb7/opt/bin/python.exe '-Bc:\nrf\samples\bluetooth\dmic_thingy53\build' -GNinja '-Sc:\nrf\samples\bluetooth\dmic_thingy53'

 *  The terminal process terminated with exit code: 1. 
 *  Terminal will be reused by tasks, press any key to close it.