Issue on generating an I2S signal on the adafruit nrf52840 board (MDBT50Q)

[abdelali]

Hi,

I'm using the I2S for driving a Neopixel (WS2812b) , my code is working properly on the nrf52840DK . but when i flashed it to the adafruit nrf52840 board via the P19 debug out port ; the download was successful but the board doesn't control the Neopixel !

NB:

• I have made sure of the adafruit board pins mapping to the nrf52840 dk.
• The same Neopixel was working properly with the adafruit board, when using the Arduino firmware with the adafruit Neopixel library (i think they use pwm for that)!
• The Adafruit board is separately powered through the usb .

Raytac_MDBT50Q.pdf

[Vidar Berg]

Hi,

I would have expected it to work since you have updated the pin mapping. Can you measure and see if you get the same IO voltage level on the Arduino feather as you do on the DK? Also, do you have access to a scope or logic analyzer so you can check if the data is actually getting clocked out on the pin?

[Johnny]

According to this post https://devzone.nordicsemi.com/f/nordic-q-a/55802/driving-ws2812b-neopixels-with-i2s-without-sck-lrck , the LRCK pin seems to be required on the NRF52840, while it was not required on the nrf52832. Maybe that's why your code isn't working now. It did fix it for me.