Hey everyone,
I was wondering whether anybody has tried getting an ADV7280A-M chip to work with the raspberry pi CSI connector. While doing some research on the topic it seems that until now only the evaluation board has been tested successfully. Also the driver for the chip is already in the kernel according to this link.
My idea is to design a small raspberry shield that goes on top of a rasperry pi and connects with the standard fpc cable to the CSI connector underneath. The design is currently ready so far. If anyone is interested i will gladly share the kicad files.
One remaining concern is whether this approach could be successful or not. If anybody has some expirience with this IC i would really appreciate your help with this
yupp - @autr and i did some experiments with this back in 2019 - even laid out a test board similar to what you describe (cant find a picture of it right now but is kicking around studio somehwere) …
if i remmeber rightly it was working on some older version of rpi os then we didnt yet figure out how to get it working on an updated one but it was a while ago now… kinda parked it
Yes yes, our initial test worked great, but problems with the new OS - basically needed a solid chunk of time to debug. Some blockers were then having no apartment, and also losing my studio to real estate developers (Berlin is insane!), and then a 2 year project which involved working abroad. We will return to it which is also maybe serendipitous 5 years later because the new Pi5 has 2 x CSI inputs. Videomischer ahoy!
Ah I see. Sounds like quite a journey. I hope all is well with you.
It’s reassuring to hear that this should in principle work. From what I could tell the CSI fpc connector is also standardized so you could use this board with other sbc’s like the jetson nano or lucky fox modules. But I don’t really if the drivers are in the kernel for these boards.
For now I guess I’m going to order the PCB’s sometime in winter.
Using two of the ICs for a video mixer is a cool idea! Are you planning on making this project open source when you get around to it?
Thanks for your quick replies.
Sure, I imagine it would be open source - the synthesizer I’ve been building since 2016 has two codebases: a backend infrastructure for the people, and a frontend implementation for personal artworks as Autr. So this is hardware / backend.
The hardware itself works better than I expected. I got no crashes and the picture is stable. Unfortunately I do not have time at the moment to test this in depth… Hopefully in the next few month I get around to do some recordings with the setup and post these here
edit: Analog devices sent me two sample ICs. These are ADV7280-M not ADV7280A-M I’m not sure if there is a difference in picture quality…
Here are my notes from 2022/23. A little disorganised, but I think I was trying to work out which chips have pre-existing Linux support, which have open source drivers from Analog Devices, and also which are being produced still. For video quality keeping an eye out for how many times the signal is oversampled (ie. clock speed of ADC), with ADV7184 supposed to be specifically for unstable or noisy signals.
ADV7280A: CVBS (composite), S-Video (Y/C), and YPrPb (component)
ADV7281A: CVBS (composite), S-Video (Y/C), and YPrPb (component)
ADV7282: CVBS (composite), S-Video (Y/C), and YPrPb (component)
Differential Video Input Support(for noisy signals):
ADV7280A: N/A
ADV7281A: Fully differential, pseudo-differential, and single-ended CVBS video input support
ADV7282: Fully differential, pseudo-differential, and single-ended CVBS video input support
STB Diagnostics (Set Top Box television stuff):
ADV7280A: Not specified
ADV7281A: STB diagnostics on 2 video inputs
ADV7282: Not specified
Common-Mode Input Range (noisy amplified signals):
ADV7280A: Up to 1.47 V common-mode input range solution
ADV7281A: Up to 4 V common-mode input range solution
ADV7282: Up to 4 V common-mode input range solution
Additional Video Enhancement Features:
ADV7280A: Integrated I2P video output converter (deinterlacer)
ADV7281A: N/A
ADV7282: Adaptive Digital Line Length Tracking (ADLLT), signal processing, and enhanced FIFO management provide mini-time base correction (TBC) functionality. 5-line adaptive 2D comb filter and CTI/DNR video enhancement.
Output Interface:
ADV7280A: 8-bit ITU-R BT.656 YCrCb 4:2:2 output and HS, VS, or field synchronization
ADV7281A: MIPI CSI-2 Tx output interface
ADV7282: N/A
Chips Without Drivers
ADV7188
• Multiformat video decoder supports NTSC (J/M/4.43), PAL (B/D/G/H/I/M/N), SECAM
• Integrates 4 x 54 MHz, Noise Shaped Video (NSV®), 12-bit ADCs
• SCART fast blank support
• Clocked from a single 28.63636 MHz crystal
• Line-locked clock-compatible (LLC)
• Multiformat video decoder supports NTSC (J/M/4.43), PAL (B/D/G/H/I/M/N), SECAM
• Integrates 4 x 54 MHz, 10-bit ADCs
• SCART fast blank support
• Clocked from a single 28.63636 MHz crystal
• Line-locked clock-compatible (LLC)
• Adaptive Digital Line Length Tracking (ADLLT™), signal processing, and enhanced FIFO management give mini-TBC functionality
• 5-line adaptive comb filters
• Proprietary architecture for locking to weak, noisy, and unstable video sources such as VCRs and tuners
• Subcarrier frequency lock and status information output
• Integrated automatic gain control (AGC) with adaptive peak white mode
• Macrovision® copy protection detection
• Chroma transient improvement (CTI)
ADV7401
Four 10-bit ADCs sampling up to 140 MHz
12 analog input channel mux & SCART fast blank support
Internal Anti-Alias Filters
NTSC/PAL/SECAM color standards support
720p-/1080i-component HDTV support
Digitizes RGB graphics up to 1280 × 1024 @ 75 Hz (SXGA)
• 525p-/625p-component progressive scan support
• 24-bit digital input port supports data from DVI/HDMI Rx IC
• Any-to-any, 3 × 3 color-space conversion matrix
• Industrial temperature range (−40°C to +85°C)
• 12-bit 4:4:4/8-bit 4:2:2 DDR pixel output interface
• VBI data slicer (including TeleText)
