J K

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6 years, 10 months ago.

Problems with Nucleo F767Zi

I tried to test the oled display with the Nucleo F767Zi and the program wasn't working at all, even the led on the board was not blinking. I am not really sure how to interpret the leds from the Nucleo board, but it looks like a run time crash to me.

I switched to a LPC1768 and there everything worked fine.

I really don't know where to start to find the problem.

Anyone any idea?

Regards, Joerg

Question relating to:

Last updated: 30 Jun 2015

Hi :),

Have you tried running a simple example program located here:

https://developer.mbed.org/platforms/ST-Nucleo-F767ZI/

Just to make sure?

Which example program did you use?

Regards,

Andrea, team mbed

posted by Andrea Corrado 06 Jun 2017

My test with the nucleo board was with mbed-os and the test with the LPC1768 was with "old" mbed. Now, i tried it with Nucleo and mbed ( not -os) and I got the error 230 "Syntax error(s) in Assembly".

posted by J K 06 Jun 2017

Yes, the nucleo board itself is running fine. I am doing some BLDC motor controlling stuff and I switched to it from the LPC1768 because I needed more memory. Now I simply wanted to add a display to my setup. I used more or less the test program from the library and only the I2C setup.

posted by J K 06 Jun 2017

I switched back to mbed-os and made a funny observation. When I started to test the display, I took all my other code out, but I left in the includes. So I took them out now ... and the display was working fine. I put back the includes and it stopped working. But * after that point, I could do in the code whatever I like, it did not work again. When I started working with the nucleo board, I realized, that he already reacts when you download the binary file to the board. He stops the current program when you start the download and starts the new one when it is downloaded. This is especially dangerous under Linux, because you have to sync the filesystem to force the data to be written to the device. And it looks like he hangs himself up every now and then. Now it feels like, I did a lot of my display testing with a defunkt mbed firmware on the board. This didn't happen before but since I use the OLED display, it happens very often

posted by J K 06 Jun 2017

1 Answer

Bruce Tomlin
6 years, 10 months ago.

I just had a similar problem with a generic SSD1306 and a Nucleo F767ZI. My problem turned out to be a lack of I2C pull-up resistors.

The Nucleo F767ZI does not include pull-up resistors on the I2C lines. Without them it worked well enough for a simple I2C scanner to see the display, but it was unable to properly communicate beyond that. A 4.7K resistor between the display VCC and each of SCL and SDA should be sufficient.