How to use 'bcm2835' to control 'PmodAd1' so that he can at least 500KSPS sample rate?

Question

my device is 'raspberry pi 3' I am using 'PmodAD1', a 12bit ADC with 1Msps sampling rate https://digilent.com/reference/pmod/pmodad1/start

Due to linux's 'spidev' system, my sample rate is compressed to only 20KSPS left

I have tried using 'DMA' to increase my sample rate

But due to lack of expertise, I can't understand how to modify

So I used the method of modifying bcm2835 to increase my sampling rate

Using mcp3008 to test successfully pulled the sampling rate to 130KSPS but still not enough for the sampling rate I need

I refer to this article to modify PmodAD1

But don't know how to modify the following CODE so it ends in failure

       bcm2835_spi_transfernb(buf_0, readBuf_0, 2);
        fprintf(f_0, "%d\n", (readBuf_0[0]<<6) + (readBuf_0[1]>>2));

Next I try to use pigpio to receive my ADC

But the baud rate he sends is not enough to get the sample rate I want

So I would like to ask how to modify the code below 'bcm2835' so that my ADC can work normally?

       bcm2835_spi_transfernb(buf_0, readBuf_0, 2);
        fprintf(f_0, "%d\n", (readBuf_0[0]<<6) + (readBuf_0[1]>>2));

Or does anyone sell a sound card with a sample rate of 300-400 KSPS

Thanks guys, I really want to get this done quickly

Ask the author of that blog if he thinks what you want is doable. In particular will it capture the number of samples you need to capture. — joan, May 22 '22 at 17:41
Does this answer your question? How can I modify my sampling rate using methods other than DMA? — joan, May 22 '22 at 17:58
This may not solve my problem That article was posted by me Still haven't been able to solve my problem As for the DMA problem, because I still don't understand how to modify it I have asked the author a question But I can't send my message — user19104274, May 22 '22 at 18:55
Why are you using bcm2835? This is very old and the "documentation" leaves a lot to be desired and seems little used. See Controlling Raspberry Pi GPIO with c and Python for comments about libraries. — Milliways, May 23 '22 at 00:56
You haven't responded to earlier questions about OS & model. You should tag the Question, not bury in the text. — Milliways, May 23 '22 at 00:57
Because the default SPI transfer rate of the Raspberry Pi is too slow The speed is only 200Kbps (20ksps sampling rate). At present, the BCM2835 function library has been successfully used to control the speed of nearly 3.6Mbps (300ksps), but it is still unable to reach the sampling rate I want. — user19104274, May 23 '22 at 03:52

0 Answers0