OLED SSD1306 with nRF52840 DK Not Working

RE: OLED SSD1306 with nRF52840 DK Not Working

Jimmy Wong — Tue, 05 Mar 2019 12:01:59 GMT

Here are using the latest SDK 15.2/15.3 with SSD1306 (NRF52840 example)

RE: OLED SSD1306 with nRF52840 DK Not Working

Vishal Aditya — Fri, 22 Feb 2019 06:13:15 GMT

https://github.com/electronut/ElectronutLabs-bluey/tree/master/code/bluey-OLED
Hope! you will also help some other developer somewhere in return...

Regards
Vishal Aditya
Embedded Software Engineer

RE: OLED SSD1306 with nRF52840 DK Not Working

abhibera — Sat, 02 Feb 2019 11:38:26 GMT

What update did you make? I am assuming you were using the ADA Fruit OLED drivers?

RE: OLED SSD1306 with nRF52840 DK Not Working

awneil — Thu, 06 Dec 2018 10:50:19 GMT

Excellent!

Now please Verify the Answer - so that the forum will show that the thread has a solution:

EDIT

Might also be helpful to say what "GFX Library" you're using, which version wasn't working, and which version made it work.

RE: OLED SSD1306 with nRF52840 DK Not Working

Vishal Aditya — Thu, 06 Dec 2018 10:23:42 GMT

Thanks a lot for your support!
Now our device is working.

*Solution: Update GFX Library
github.com/.../bluey-OLED

RE: OLED SSD1306 with nRF52840 DK Not Working

Jørgen Holmefjord — Tue, 04 Dec 2018 08:04:43 GMT

Ok, let me know if you get it working or not. I only had time to test your code quick, an it gave me the same pattern on the display only inverted.

RE: OLED SSD1306 with nRF52840 DK Not Working

gauthamranganathan — Tue, 04 Dec 2018 07:36:16 GMT

Thanks a lot for your reply.

I tried using the nrfx_twi driver. On entering debugging mode, I was able to see the the length variable in function call nrfx_twi_tx was 1024 (as expected). But the OLED is still behaving the same way. I will try once again till tomorrow and if I'm unable to do it then I will convert this to a private ticket and post my source code.

Initially you mentioned that you found similar behavior on your display as well. Were you able to get it working?

Thank you.

Gautham

RE: OLED SSD1306 with nRF52840 DK Not Working

Jørgen Holmefjord — Mon, 03 Dec 2018 09:28:42 GMT

Hi,

The legacy TWI master driver in the SDK was limited to 255 bytes, as the driver combined support for TWI and TWIM peripherals. The EasyDMA length of TWIM was limited to 255 bytes in nRF52832. To transmit longer packets, I would recommend switching to the new NRFX drivers. You can use the nrfx_twi.c driver for the legacy TWI periperal (no EasyDMA support), that should work on all nRF52 series ICs, or even better i your case, you can take advantage of the support for 16-bit EasyDMA MAXCNT bit length for TWIM peripheral in nRF52840 and use the nrfx_twim.c driver. These drivers does not have the uint8_t limitation for the length field. Please have a look at this page for details on migration from legacy drivers to nrfx.

Best regards,
Jørgen

RE: OLED SSD1306 with nRF52840 DK Not Working

awneil — Mon, 03 Dec 2018 08:59:20 GMT

[quote userid="73059" url="~/f/nordic-q-a/40693/oled-ssd1306-with-nrf52840-dk-not-working/159856"]Please let me know how I can proceed with this[/quote]

You really need to get an analyser on the bus to see exactly what is happening in both the "working" and the non-working cases.

Look at the difference(s), and then consider what could cause those differences.

Otherwise, you are just guessing.

Also compare the captured traces carefully with the display specifications - it is possible that the "working" case is marginal...

Cheap analysers are available on the likes of ebay for $10 or less.

RE: OLED SSD1306 with nRF52840 DK Not Working

gauthamranganathan — Mon, 03 Dec 2018 04:29:31 GMT

Hi, i am working on OLED with Vishal.

Current situation : OLED working well on the nrf51422 target board and DK PCA10028.

OLED is not working as expected in the target board (mdbt module housing nrf52840) or with the PCA10056 DK

The ssd1306 driver file used is the same in both the cases.

After going through the c files, we have narrowed the problem to the TWI function calls.

In the working code (nrf51422 SDK 10) the nrf_drv_twi_tx function has a length of type uint32_t but the SDK 15.2 has a length of uint8_t. The max value of length that can be passed to the TWI tx function call is MAXUINT8 (0xFF).

The OLED driver requires us to send more than 0xFF bytes at once.

We think the previous developer has modified the nrf_drv_twi files and made it support a larger value of length. However, I do not want to introduce changes in the library files as this might lead to other bugs.

So, I would like to know how to send more than 0xFF bytes in a single TWI command?

I have tried splitting the data into multiple buffers of size 256 and then calling the TWI TX function repeatedly but this is not working either. (the reason could be that on each function call, the SLAVE ADDRESS will be produced on the bus. This is not part of the OLED command sequence and would lead to unexpected behavior).

Please let me know how I can proceed with this.

Thanks in advance.

Gautham

RE: OLED SSD1306 with nRF52840 DK Not Working

awneil — Sat, 01 Dec 2018 14:11:05 GMT

Can't your oscilloscope do screenshots?

Show the oscilloscope trace for the nRF52840.

RE: OLED SSD1306 with nRF52840 DK Not Working

Vishal Aditya — Sat, 01 Dec 2018 05:39:16 GMT

[quote userid="6462" url="~/f/nordic-q-a/40693/oled-ssd1306-with-nrf52840-dk-not-working/159749"]I think he wants you to fix his code for him?[/quote]

I don't want code fix, I know my job I will do it myself. The issue is all other i2c peripherals are working properly with the same twi_init() & sdk_config.h except for OLED & all the display sequence initialization is correct. I have checked the OLED sequence begin multiple times.

i2c bus line on Oscilloscope I get this in nrf51422 device:

Yellow: SCL
Blue: SDA

& no proper pattern on nrf52840 device.

awneilLet me know if you need any more info further!

RE: OLED SSD1306 with nRF52840 DK Not Working

awneil — Fri, 30 Nov 2018 15:07:53 GMT

I think he wants you to fix his code for him?

Vishal Aditya Getting the display initialisation correct & working is your job.

Have you checked your initialisation sequence against the display's specifications?

Have you used a scope or analyser yet to see what is actually being sent to the display?

Have you compared that to the "working" case ?

RE: OLED SSD1306 with nRF52840 DK Not Working

Jørgen Holmefjord — Fri, 30 Nov 2018 14:54:11 GMT

I do not understand your question.

RE: OLED SSD1306 with nRF52840 DK Not Working

Vishal Aditya — Fri, 30 Nov 2018 07:05:31 GMT

Can you indicate the line no. or changes required for the same?

RE: OLED SSD1306 with nRF52840 DK Not Working

Jørgen Holmefjord — Tue, 27 Nov 2018 16:11:43 GMT

I'm seeing similar behavior on my display. I think there is something wrong with the initialization.

RE: OLED SSD1306 with nRF52840 DK Not Working

Vishal Aditya — Tue, 27 Nov 2018 06:34:21 GMT

Any updates on OLED test?

RE: OLED SSD1306 with nRF52840 DK Not Working

Vishal Aditya — Thu, 22 Nov 2018 15:37:49 GMT

Please check your INBOX

RE: OLED SSD1306 with nRF52840 DK Not Working

Jørgen Holmefjord — Thu, 22 Nov 2018 14:51:40 GMT

If you do not want to post it in public, I can convert the case into a private one. Or you can upload it to some filesharing site and send me the link in a private message.

RE: OLED SSD1306 with nRF52840 DK Not Working

Vishal Aditya — Thu, 22 Nov 2018 14:31:36 GMT

Please reply with your email id. Full project folder is not required, I have created another twi_scanner directory with OLED drivers merged.

RE: OLED SSD1306 with nRF52840 DK Not Working

Jørgen Holmefjord — Thu, 22 Nov 2018 14:05:47 GMT

I think you are seeing this behavior because you are not sending the correct commands to the display to configure it. Have you checked the TWI bus with a logic analyzer to see what is transferred to the display?

If you upload your entire project, I can test it and see if I can make it work with similar display.

RE: OLED SSD1306 with nRF52840 DK Not Working

Vishal Aditya — Thu, 22 Nov 2018 06:21:51 GMT

Update: I am getting TWI address: '0x3c' & device_detected: true. I have a similar custom board also with same OLED & same issue. Please check the attached image.

RE: OLED SSD1306 with nRF52840 DK Not Working

Jørgen Holmefjord — Wed, 21 Nov 2018 13:37:24 GMT

Were you not able to find the TWI address of the display using the TWI_scanner example on those pins either?

RE: OLED SSD1306 with nRF52840 DK Not Working

Vishal Aditya — Wed, 21 Nov 2018 06:31:20 GMT

I have tried on SCL: P0.27 and SDA: P0.26

ssd1306_init_i2c(OLED_SCL, OLED_SDA);
ssd1306_begin(SSD1306_SWITCHCAPVCC, SSD1306_I2C_ADDRESS, true);

Same issue!

This is how my sdk_config.h looks like:

Also, my twi_init() is in ssd1306.c driver file not in main.c and same is the case with nrf51422 sdk code which works but not nrf52840 sdk15.2 ble_app_uart code.

I think it's something to do with i2c configuration in twi_init or NRF_DRV_TWI_INSTANCE or sdk_config.h but I can't figure it out.

RE: OLED SSD1306 with nRF52840 DK Not Working

Jørgen Holmefjord — Tue, 20 Nov 2018 13:31:11 GMT

Have you tested other pins? P0.13 and P0.14 are used for LEDs on the DK. Unless you have disconnected the LEDs using the solder bridges, and made sure you do not initialize the LEDs in your code (for instance through BSP library), you should not use these pins for TWI.