Interfacing ADC with RasberryPi 5 - Page 1
Forum section: electronics / general

author: yammy_96
author_rank: Newbie
timestamp: September 14, 2025, 03:52:48 pm
content: I am using the AD9629 20Msps 12-bit-parallel-output ADC. I want to stream this 20Msps x 12-bits into a rasberry pi and perform FFT moving average in real time. The AD9629 has a DCO pin which outputs a clock to synchrozie the 12-bit outputs to external latches.Is connecting the AD9629 to a FT600Q USB FIFO a good idea? Would I need an FPGA or small logic to interface the ADC outputs with the FT600Q? Can the FT600Q can be pin strapped to stream the ADC data continusly through USB into the rasberry pi?Would you recommend another way to stream and process this data?AD9629 datasheet:https://www.analog.com/media/en/technical-documentation/data-sheets/ad9629.pdfFT600Q datasheet:https://ftdichip.com/wp-content/uploads/2020/07/DS_FT600Q-FT601Q-IC-Datasheet.pdf

author: Gleeson
author_rank: Contributor
timestamp: September 15, 2025, 05:51:24 pm
content: I can't speak to what is possible with the raspberry pi, but I can tell you that you will definitely need an FPGA (or some other programmable logic) between the AD9629 and the FT600Q.

author: radiolistener
author_rank: Super Contributor
timestamp: September 15, 2025, 06:08:29 pm
content: You can try to use FT2232H in FT245 synchronous FIFO mode, in theory it supports up to 40 MB/sec.20 MSa/s x 12 bit = 240 MBit/sec = 30 MB/sec which is well fit its bandwidth.I'm not sure that Rasberry Pi 5 will be able to process such stream in realtime, but it worth to try.I can say that it can do 2.4 MSa/s with no issue.

author: rteodor
author_rank: Frequent Contributor
timestamp: September 15, 2025, 06:13:27 pm
content: Only throwing my 2c into your discussion: maybe SMI: secondary memory interfacehttps://iosoft.blog/2020/07/16/raspberry-pi-smi/Quote from: T.F.A.Well, hope that helps.

author: radiolistener
author_rank: Super Contributor
timestamp: September 15, 2025, 06:38:27 pm
content: Quote from: rteodor on September 15, 2025, 06:13:27 pmwow, very interesting article, thanks a lot

author: langwadt
author_rank: Super Contributor
timestamp: September 15, 2025, 07:28:47 pm
content: the RasberryPi 5 doesn't have SMI like the previous RasberryPi's, all the IO has been moved to the RP1 chip which is on PCIethe RP1 has a PIO block like RasberryPi pico, it might be possible to use that

author: rteodor
author_rank: Frequent Contributor
timestamp: September 15, 2025, 08:13:20 pm
content: Quote from: langwadt on September 15, 2025, 07:28:47 pmYep, forgot that Pi5 had a lot of changes. From what I've read RP1 PIO's should be available for programming:https://www.raspberrypi.com/news/piolib-a-userspace-library-for-pio-control/It seems like its more work than with SMI but with PIO being way more flexible it might be even better.Quote from: radiolistenerI've wanted to play with this SMI interface for quite a while but there was always more important to do. Since I know you are into SDR's maybe check this one which uses SMI:https://www.crowdsupply.com/cariboulabs/cariboulite-rpi-hat

author: langwadt
author_rank: Super Contributor
timestamp: September 15, 2025, 08:47:48 pm
content: https://wiki.sipeed.com/hardware/en/tang/Tang-Nano-9K/Nano-9K.htmland thishttps://www.gowinsemi.com/en/market/featured_detail/13/?