Thingy53 - Unable to get a SSD1306 OLED display to work with I2C Stemma/Qwiic

Question

Hello, I've been trying to get a SSD1306 128x64 OLED display to work with a Thingy53 using the I2C Stemma/Qwiic connector. I've used the SSD1306 display many times with nRF52840 and numerous other ARM devices under Zephyr RTOS without any issues. I have read several related devzone issues but cannot see how to get a simple SSD1306 OLED to work with the Thingy53 nRF5340. Exactly the same code works on nRF52840 with its overlay for the SSD1306 display. The only difference seems to be that Thingy53 nRF5340 uses compatible "nordic, nrf-twim" vs. "nordic, nrf-twi". What am I missing? I would appreciate your assistance to determine why the overlay below isn't working and needs to be connected. Thank you. I have a thingy53_nrf5340_cpuapp.overlay, as below I get the following errors: 00> rtt:~$ [00:00:00.051,788] i2c_nrfx_twim: Error 0x0BAE0001 occurred for message 1 00> rtt:~$ [00:00:00.051,788] ssd1306: Failed to initialize device! 00> rtt:~$ *** Booting nRF Connect SDK v2.5.0 *** 00> rtt:~$ rtt:~$ [00:00:05.002,105] main: main_thread 00> rtt:~$ [00:00:05.002,166] main: Zephyr RTOS: 3.4.99 00> rtt:~$ Could not finalize framebuffer (err -19) 00> rtt:~$ Could not finalize framebuffer (err -19) 00> rtt:~$ Could not finalize framebuffer (err -19) 00> rtt:~$ Could not finalize framebuffer (err -19) Best Regards.

khelmutlord · Accepted Answer

Oh! I just noticed! Flip your SDA and SCL lines. P0.04 is SCL and P0.05 is SDA.

zpm1066 · Answer

Hi Helmut, 
 Thank you. Switching the SDA & SCL lined worked! I guess, it had to be a simple error. 
 Also ended up increasing the buffer size to 4096. 
 zephyr,concat-buf-size = <4096>; 
 The Thingy53_UG (page 17) has an error relating to the I2C Stemma/Qwiic SDL and SC pin assignments..