Some doubts about the use of dma in esp32-web-camera
Posted: Wed Jan 25, 2023 1:53 pm
Reading the code in the dma section of the esp32-web-camera project (ll_cam.c), I found that esp32, esp32s2, esp32s3 have major differences in dma, I don't understand what are the reasons for these differences?
1. esp32 defines multiple sampling modes, i2s_sampling_mode_t, what do these modes mean? Why do they not appear in esp32s2 and esp32s3?
2. xclk_freq_hz, for esp32, is handled differently depending on whether it is greater than 10000000, while esp32s2, esp32s3 is not?
3.I2S0 How is this global variable set to implement the dma function? What is the purpose of setting the parameter to 1 and then immediately setting it to 0?
Just entered the esp32 field, for some concepts may not be familiar, so may be a lot of questions, rather superficial, please forgive me.
Translated with www.DeepL.com/Translator (free version)
1. esp32 defines multiple sampling modes, i2s_sampling_mode_t, what do these modes mean? Why do they not appear in esp32s2 and esp32s3?
2. xclk_freq_hz, for esp32, is handled differently depending on whether it is greater than 10000000, while esp32s2, esp32s3 is not?
3.I2S0 How is this global variable set to implement the dma function? What is the purpose of setting the parameter to 1 and then immediately setting it to 0?
Just entered the esp32 field, for some concepts may not be familiar, so may be a lot of questions, rather superficial, please forgive me.
Translated with www.DeepL.com/Translator (free version)