Need guidance on next steps in big project - Page 1
Forum section: electronics / projects

author: Boscoe
author_rank: Frequent Contributor
timestamp: October 27, 2023, 06:56:31 pm
content: Hi all,I'm currently working on a personal dream of mine to make a good digital camera from scratch, I plan to use it as my go to camera.You can see the initial bits I've written here to get an idea of the project.https://docs.google.com/document/d/1gnEBzrgK05kzuTFEPspbsJ127sbl_kKvJMLyx1T--wY/You can download the repo, schematics and gerevers etc. here:https://github.com/gswdh/CameraElectronics/releasesSo, I have assembled one of the PCBs and have worked through all the aspects of the design, verifying them one by one. There were many issues however, luckily, all but one was critical.The critical issue:I only receive garbage data from the image sensor. I have reviewed and triple checked my sensor start up routine, configuration values (they are given in the datasheet for an example config) and simply receive garbage across the 16 LVDS channels when they should all be transmitting the same sync code. I've got to the point where I feel I have no where to go with this set of HW; either there's a problem with the design, damaged component or it's beyond my abilities.My choices going forward:1. Get a new design of the PCB fabricated and populate it with the second image sensor I have.- The GMAX0505 image sensor I used on this first board had been soldered and desoldered aggressively once already and has visible signs of this which means it might be broken causing the issue I face.- Here I would be spending another ~€350 on PCBs on just the chance it's because my current sensor is broken. So it's a 50/50 chance of loosing ~€500 with components.- The manufacturer of this sensor has zero support and one not-so-good datasheet. Their example HDL for their FPGA based dev is is atrocious for example.- I want to make more cameras, this sensor is quite pricey at ~€650 each once they get from China to Europe.2. A new PCB design with a new sensor.- Since I started this project (coming out of COVID) there's many more sensors on the market that one can actually buy.- Sensor prices could be from ~€300 to ~€600.- OnSemi, for example, has all the IP ready to be implemented in your Xilinx block design with all the constrains etc. needed. The documentation for it is fantastic, too.I feel like going for a new sensor would be better. It would also mean I can just buy it from Digikey rather than having to import from China.How would you take this project forward?Many thanks for your thoughts.

author: moffy
author_rank: Super Contributor
timestamp: October 27, 2023, 11:18:54 pm
content: Go for the new sensor from a reputable manufacturer with good documentation and support, OnSemi. The support is often as importatnt as the product.

author: Someone
author_rank: Super Contributor
timestamp: October 27, 2023, 11:58:56 pm
content: Quote from: Boscoe on October 27, 2023, 06:56:31 pmBuy an off the shelf camera with the sensor and optics already designed/mounted/manufactured/etc. If you really want to replace the electronics side have at it but start with half the system already working/validated.One off sensors often cost more than the consumer products that contain them!

author: pickle9000
author_rank: Super Contributor
timestamp: October 28, 2023, 12:27:05 am
content: Wow that's a crazy project, best of luck to you.I personally would see if any of the vendors for the sensor have some configuration software, sample software prior to picking a sensor.You may get lucky and get a demo board and sdk from a manufacturer.

author: Boscoe
author_rank: Frequent Contributor
timestamp: October 28, 2023, 11:45:15 am
content: I totally agree with you. However, how having played with the project from OnSemi, it only supports Ultrascale FPGAs, I’m using a Zynq 7000. So, although their example are still useful, they don’t provide that piece of mind of a high probability of working without major issues.I should mention I already have a second sensor of the one I have which makes it kinda free at this point.

author: Boscoe
author_rank: Frequent Contributor
timestamp: October 28, 2023, 11:47:09 am
content: Quote from: Someone on October 27, 2023, 11:58:56 pmUnfortunately, this doesn’t work. 1. I want to design it myself. 2. It’s very hard to find the part numbers of the sensors used in off the shelf products, there’s no chance of getting docs for the electronics pin out and the sensors are often custom (Sony inparticular). 3. They won’t fit in the form factor I want.

author: Someone
author_rank: Super Contributor
timestamp: October 28, 2023, 10:32:18 pm
content: Quote from: Boscoe on October 28, 2023, 11:45:15 amThere are very few physical things a Zynq 7000 (which part?) cant do that an Ultrascale can, if thats the sort of thing which roadblocks you then the project is probably out of reach. One of the core values of an FPGA is being able to retarget the concept to other families/brands.

author: Someone
author_rank: Super Contributor
timestamp: October 28, 2023, 10:35:13 pm
content: Quote from: Boscoe on October 28, 2023, 11:47:09 amOk so then you've flipped it around, the optical design is important but you dont have the skills to do the electronics. What form factor is impossible to meet with existing camera parts but would be possible with DIY/hobby assembly? This sounds like a project full of impractical limitations baked in from the outset.

author: MathWizard
author_rank: Super Contributor
timestamp: October 29, 2023, 08:05:39 am
content: Do these things run faster enough that you have to worry much about trace length's and multi-layer PCB's ?

author: tooki
author_rank: Super Contributor
timestamp: October 29, 2023, 12:37:31 pm
content: And let’s not forget that signal processing is absolutely critical to getting good image quality. This is so difficult that really, only huge companies can afford to invest in it: this is why the image from the same camera, taken in raw format, can look totally different depending on what software is used to process it. It’s why smaller camera companies (like Leica) have awful in-camera processing, and their users have to rely on good raw processing on their computer to get the most out of their camera. It’s how the smartphone companies get great images out of tiny (=inherently noisier) sensors, and how Nikon still has the reputation of producing the very best in-camera processing in their SLR and mirrorless cameras.OP hasn’t explained what it is they really want to accomplish, but it’s almost guaranteed that there exists some off the shelf camera that will do a better job for far less money, never mind the effort.

author: jonpaul
author_rank: Super Contributor
timestamp: October 29, 2023, 01:25:47 pm
content: see Phase One digital backs for medium format professional cameras.https://www.phaseone.com/Fine products and design up to 80..160 M pixels.Jon