Jörg Rohde

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10 years, 8 months ago.

SPI frequenzy

Hi, I´m testing the Nucleo to work with the Adafruit TFT Touch Display with SPI Interface. I have found several helpfull librarys and I have got output to the screen. But I can not raise the SPI frequenzy above 4MHz. When I initalisize the SPI interface with 5 or 10MHz I got a SPI frequenzy of 30KHz. Did anyone have a solution? Is there a bug in the mbed lib? Thanks in advance.

Question relating to:

Last updated: 20 Apr 2021
Affordable and flexible platform to ease prototyping using a STM32F103RBT6 microcontroller.

Hello Jorg Rohde,

it's a known limitation by current nucleo implementation, here some information : http://mbed.org/forum/bugs-suggestions/topic/4752/

Regards,
0xc0170

posted by Martin Kojtal 16 Mar 2014

2 Answers

Peter Drescher
10 years, 8 months ago.

You have to increase the working frequency of the board to use a faster SPI clock. The boards are running at 16MHz out of the box.

You can multilpy this with the internal pll. See https://mbed.org/users/dreschpe/code/ST_L152_32MHZ/ to have a starting point. You have to change this code to fit for the F103.

Jörg Rohde
poster
10 years, 8 months ago.

Thank you Martin and Peter. Yesterday I took a look on the F401 code from Peter but the Cube is no help for the F103. But I forgot that you wrote a patch for the 152 also. Many thanks and also for the TFT.lib I have to make litle changes for my Adafruit SPI TFT but the roots are from your code. Regards Jörg