ESP8266 Community Forum

- Fri Sep 18, 2015 12:14 pm #29375 Hi,

I try to use SPI bus at a different speed than default settings.

I use the following code to set up the MaxSpeed

Code: Select allvoid setup()
{

  // initialize SPI:
  SPI.beginTransaction(SPISettings(100000, MSBFIRST, SPI_MODE0));
  SPI.begin();

The compilation is OK but it has no effect on the clock frequency which is still 1MHz

SPI_freq.jpg

Could you please help me ?
Thanks
JP

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Last edited by freedom2000 on Fri Sep 18, 2015 4:18 pm, edited 1 time in total.

- Fri Sep 18, 2015 3:30 pm #29384 I don't know if it is the reason, but SPI.begin() should be called before SPI.beginTransaction().
You can also call SPI.setFrequency(), but again, it must be done after the SPI.begin().

- Fri Sep 18, 2015 4:17 pm #29388 You are a BOSS

Code: Select all  // initialize SPI:
  SPI.begin();
  SPI.setFrequency(500000);

SPI_freq2.jpg

Thank you
JP

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