Search found 3 matches

by zotikus
Sat Jan 12, 2019 4:56 am
Forum: Hardware
Topic: SPI slave driver, last 4 Bytes missing (using DMA)
Replies: 15
Views: 2243

Re: SPI slave driver, last 4 Bytes missing (using DMA)

Hi, When configuring spi_bus_config_t, by default max_transfer_sz, is 4094 Bytes. i.g. spi_bus_config_t buscfg={ .miso_io_num=PIN_NUM_MISO, .mosi_io_num=PIN_NUM_MOSI, .sclk_io_num=PIN_NUM_CLK, .quadwp_io_num=-1, .quadhd_io_num=-1, .max_transfer_sz=0 //in bytes, default is 4094 }; If you go to spi_co...
by zotikus
Sat Jan 12, 2019 12:15 am
Forum: ESP32 IDF
Topic: SPI transaction interval
Replies: 4
Views: 552

Re: SPI transaction interval

Hi @squonk11, First time I hear this "peculiarity", do you have a source where to find more about it? I have seen some posts regarding 4 bytes lost, when using SPI slave mode. I am not currently using the slave mode to verify but that is different from your use case. You can use polling as trans_res...
by zotikus
Thu Jan 10, 2019 9:10 pm
Forum: ESP32 IDF
Topic: SPI transaction interval
Replies: 4
Views: 552

Re: SPI transaction interval

Hi, I have struggled with this matter before. There are a few options to address, and it depends very much on: What is your data size (Tx) in bytes? (i.g. 3 bytes 0x06 0x00 0x00) Are they repetitive (same data sent over and over)? (i.g. last 3 bytes to transmit for lets say 3600 times) Are you expec...

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