skywater-pdk VS isc0901b0-breakout

Preferably Intel compatible or able to run Linux? Something I can build in my garage or in a simple microprocessor fab.

https://github.com/google/skywater-pdk

It looks neat, but the process node is 1 um with 3 metal layers.

The open Skywater PDK is 130 nm : https://github.com/google/skywater-pdk (though I don't know how reliable the PDK is?)

From working in a somewhat related discipline, the PDKs for the high end nodes (think tsmc N16 and lower) are quite hard to obtain and require your org to pass security audit. In addition to that the cadence licenses are priced very much for a big-org rather than a startup.

Does your chip absolutely need a modern node? I'm assuming you've seen the open source skywater pdk, but here it is just in case. https://github.com/google/skywater-pdk

If you need a free PDK, check out: https://github.com/google/skywater-pdk

That would be really neat, but I haven't seen anyone even make a CMOS imager on SKY130.

https://github.com/google/skywater-pdk

One could make an array of thermopiles, like the hacker that made their own imager out of discrete diodes (digiOBSCURA) . But each pixel would cost $7.

https://www.digikey.com/en/products/detail/excelitas-technol...

One might be able to make an array of thermistors (possibly with active cooling using a peltier) like the diycamera (digiOBSCURA) below. Might be an application of combining many RC oscillators in a tree and recovering the signal with an FFT. I have a gut feeling this is possible, but haven't show it.

https://www.digikey.com/en/products/detail/panasonic-electro...

https://github.com/IdleHandsProject/diycamera (digiOBSCURA)

One could experiment with microbolometers on tinytapeout. https://elicit.org/search?q=cmos+microbolometer

https://tinytapeout.com/

Unlike x86_64 which can only legally be produced by two and one-quarter companies, RISC-V is a permissively open-sourced ISA so anyone can make a chip. Literally, you can download Verilog of Berkeley Rocket cores from Github and run it on an FPGA, or prep it to send to SkyWater to fab at 130nm.

Taping out an actual chip inevitably involves IP that's not yours, e.g. the standard cell library and other 'physical' IP like memories and flash. You cannot open source that as it is not yours and in general the owners of it won't want to open source it either (though there are exceptions e.g. the Skywater 130nm PDK https://github.com/google/skywater-pdk).

In OpenTitan we've built all the 'logical' IP ourselves from the ground up. This is the Verilog RTL you can see in our repository but you need the 'physical' IP to make a real chip. We haven't built any physical IP so we need to get it from the traditional industry sources which means traditional industry licensing (i.e. very much not open).

I built a couple of glasgow devices and used one extensively- it becomes very useful once the IC in question has an interface you can't practically use with a microcontroller.

I used it to capture data from a thermal imaging sensor (extracted from an automotive night vision camera)- a weird ~75MHz data bus[0].

0: https://github.com/festlv/isc0901b0-breakout?tab=readme-ov-f...

There's another path to cheap thermal imaging- some premium cars have had thermal imagers for night vision (animal, pedestrian detection) for ~10 years.

The most common such system is Autoliv NV3, which is using the same sensor as Tau2/Flir E4/E8 (~320x256px). The original processing electronics does have protection preventing the use of it without car's ECU (though it's already broke), but the sensor interface is reverse engineered. Due to the age of the vehicles and the fact that the protective window in front of the lens is easily damaged, the modules can be bought relatively cheaply (I got mine for ~150EUR).

I made a breakout board for the sensor and have a more-or-less working nmigen gateware (using glasgow): https://github.com/festlv/isc0901b0-breakout

I don't have it fully working yet, as the sensor requires bias values to be sent for each pixel and Glasgow didn't have enough on-board memory to store them, and the thermal image without correct bias values is more or less unusable (many pixels are underexposed/overexposed).

I have hardware ready for ECP5 development board with enough onboard RAM but life got in the way, so it's still sitting in the pile of unfinished projects :/

There's also next generation (Autoliv NV4 == Veoneer NiVi4) which is based on 640x512 Boson sensor, though there is a lot less information about it.