Have a week or two before the first version turns up and no improvements to make until I can test the board.   In the meantime I had the idea I could adapt what I have to a board that plugs into this… https://www.aliexpress.com/item/1005008877505362.html that way it’s really cheap to have a canbus connected mini display.   Anyone can cut or print a custom front panel or mount it behind a small cutout. Only a few screws hold it together which makes it simple to assemble. Being shipped from China as DIY no need for certification like CE or FCC for radio(wifi) devices. That board already has 3 usable buttons (plus reboot) and 3 spare in/out with serial port. 2 is enough for canbus board. It has place for power in so I just need to do a 12v to 5v section and the protection circuit.

Boards have the pins labelled and aren’t locked to custom firmware so can be reprogrammed by anyone.   So far estimate around NZD$50 with the LEDs in case as shift light. Main 3 chips are around USD$9

Well ordered the first circuit boards for prototype 4.   WTF cost was USD10 shipped for 10 custom boards.   It is insane what you can fit into a tiny space. The board is 20x76mm and max 5mm high with all these features:  now 1cm longer and added reverse polarity protection. Plus no need to replace diodes for 24v vehicles.   fuse, self resetting short-circuit aka reverse polarity protection  12/24v switch mode power supply for low heat 90% efficiency  Just need to swap the fuse for use in 24v vehicles Optional ign switch input to power up Electrical power noise filtering Electrical filtering ADC pins Spare 5v and 3v3 volt outputs 4x static (ESD)protection for buttons and knobs etc 12 general purpose input/outputs Current generation CAN 2.0 controller with listen real listen only mode.  CAN bus noise filtering, ESD and voltage spike (TVS) protection optional canbus termination for aftermarket ecu 2nd bus use. ESP32 module with dual core cpu, wifi and Bluetooth  connector for firmware update and Arduino IDE supported This is massive overkill and parts are high spec low tolerance ones. board can run as almost anything, supports full LCD displays etc.      Adding web configuration for colour of each led and rpm it triggers at, mostly done. You can set can ID and bytes via web to look at so supports most cars and aftermarket ecus.  Also want to add an aftermarket mode that allows ecu to do some cool things that I have seen any other product do.    

Surprising those alpine units should sound pretty good on their own.

Being the long weekend, just been paid, thought time for a mini project - so I popped down to my local Supercheap, picked up a new Headunit for my WRX:         The mini project was ... 30 minutes all up. Including time to figure out why my front speakers weren't working, I had the RCA's for the Sub and the AMP around the wrong way.   Despite having an AMP.. this headunit sounds MUCH better. I'm happy as!