Automotive ESP32-application

[oh2ftu]

Hi,
I've installed a 5" esp32 display in my car (Mercedes V-class) to monitor some parameters and use it as a HMI for the PSM.
Sadly, some interesting information is not available via the PSM. These are namely battery current, battery temp, aux heater state to mention a few.
So .... let's find out where they are located?
Both are available as their own LIN-buses and I know where to find them.
The display is mounted, and I'm not interested in routing more cables to it. Also, all the GPIO is already in use (Waveshare 5").
What to do? well ... let's make our own PCB.
Here are the parameters that I've come up with so far:

• Input voltage 8-18V
• Some ESP32-module, but which?
• TWO LIN-transceivers, TJA1051T or similar (I'm open to suggestions)
• TWO CAN-buses, one direct and one with MCP2517 or similar
• Terminating resistors 60ohm or 120ohm available via dip-switches
• Debug via usb-C, connected directly to ESP32 usb-pins
• Integrated power supply with both 3,3V and 5V output, as little components as possible. Ideas?
• Four (just an arbitary number) leds
• Boot- and reset-buttons

Do you have any suggestions for the following:

• Power IC with 3,3V and 5V. Perhaps 500mA on both?
• ESP32-module with as many uarts as possible
• CAN-transceivers?
• LIN-transceivers?

I'm starting to put a schematic together, but it's been years since I've used kicad or designed anything

[xvr]

Maximim number of UART (6) has ESP32-P4 SoC. It also have 3 CAN controller (but no CAN PHY on chip)
Next UART number (2) has almost all.
2 CAN controllers have ESP32-C5 & C6

[oh2ftu]

This has been on hold for a while. I've been working on a proof-of-concept with my stock of parts and LINTTL3-modules.
Looking at this table I'd opt for the ESP32-C6.
I'm contemplating on a few things that I would like to have your opinions on:

• Bare module (not chip though) or pin-headers for a devkit? this would simplify the board quite a bit
• two TJA1021 or one TJA1022?
• What about LTE, should I go with a Walter? It's with a C3, so only one TWAI and two UARTs

[oh2ftu]

This chugs forward in small steps. I changed the 1117-based LDO's to two Murata OKI-78SR-series.
And as feature creep goes, I decided to replace the TJA1051's with TCAN330G. This allows me to drop the 5V rail completely and have enable-control to both lin and both can -transceivers. I think this would allow to put the board to sleep. Also, silent mode for can transceivers can be enabled or disabled at will. I might have to insert a gpio-expander here. Maybe.

[oh2ftu]

This took a sidestep, but I was able to order a batch (Assembled) from JLC.
Here are the highlights:
- MCU Esp32-C6-Wroom-1-N8. I would have used a mini-1-H8, but they were a lot more expensive
- The board grew from an initial 50x85 dual layer to 60x100 4-layer
- PSU: LMR33620CQ5RNX or ..3RNX
- CAN-transceiver: TCAN1043ADRQ1
- LIN-transceiver: TJA1021BT/0Z
- GPIO-expander (gotta have LED's): TCA6408AQPWRQ1

For connector just a plain USB-C and routed the txd0/rxd0 to a set of pin-headers. Main interfacing connector is a Phoenix MC 1,5-GF-3.5 AND a pad for an MQS 12-pin header.