OpenEVSE ESP32 WiFi Module Schematic

Is there a schematic for this board ?

In particular I’m looking for which pins the LED and SPI/I2C JST sockets are connected to.

This is related to my other thread where I’m on the hunt for a spare GPIO to operate a contactor in 3phase / pv divert mode, and the LED header may be just the ticket (depending on what the LEDs are used for).

Thank you

Here’s the open-source github repo for the OpenEVSE WiFi V1 ESP32 WiFi module

I doubt you can use this one, it seems to be wiired to one pad of Led 2 ( NS1 )

So I see… how LEDs have changed … they are now digitally controlled nightmares using WS2812B bus. Never seen that before, but quite smart looking at the data sheet. As many LEDs as you want and only use one PIN.
If I do manage to get this to work, I’ll likely use IO16 (SPI CS).
Maybe new revisions of the board will expose more IOs to play with - I do plan to replace it with the ESP32-bridge board to give me ethernet, but I’d really like something that works with all models.

maybe let the pin be configurable through /config ?

I have plan to use SPI with an external sd card reader :slight_smile:

Also seeing what you’ve said, you could hack the led output by using a little arduino that would simulate a new pixel led in the chain and taking brightness data as on / off ( 100% / 0% ).

Here’s a crazy thought… but I don’t think I have the capabilities to do it.

Use an AVR/Arduino as a SPI slave and offload all current measuring to it.
Use emonlib and (at last) get CT clamps on all phases.
Then the system could auto detect if it’s 3 phase or not (including if the vehicle connected is) and adjust all the measurement data automatically.
That AVR could also control the L2/L3 contactor and engage it as needed depending on user preference.

Taking this further, could the ESP32 not be used to do all of this ? (And that is very beyond my capabilities!)


it has yes but there’s no gpio pad on wifi module

I thought the ESP32 had ADCs ?
(I’m new to ESP32, but familiar with 8266, so hopefully won’t be too much of a transition)


it has yes but the openevse_wifi_v1 doesn’t have all the pins broken out.

You can find cheap i2C ADC boards with many inputs. This could be used easily on wifi gateway.

It would be easier to use an Adafuit Huzzah ES32 module, it has all the pins broken out and is supported by the current OpenEVSE WiFi firmware

To use the Huzzah you’ll need to compile with the openevse_huzzah32 platformio environment