adding support for WaveShare ESP32-S3-RS485-CAN

[dlarue]

Do I have it right that in order to test this board(https://www.waveshare.com/wiki/ESP32-S3-RS485-CAN) out I have to fork esphome-yambms and then create a new board file using the info obtained from their example WS_GPIO.h? Maybe copy board_ESP32-S3_LilyGo-T-Connect-Pro.yaml

WS_GPIO.h:

#pragma once

#include <Arduino.h>     // Reference the ESP32 built-in serial port library

/*************************************************************  I/O  *************************************************************/
#define GPIO_PIN_CH1      47    // CH1 Control GPIO

#define TXD1              17    // The TXD of UART corresponds to GPIO   RS485
#define RXD1              18    //The RXD of UART1 corresponds to GPIO   RS485
#define TXD1EN            21

#define TXD2              15    // The TXD of TWAI corresponds to GPIO   CAN
#define RXD2              16    // The RXD of TWAI corresponds to GPIO   CAN



/*************************************************************  I/O  *************************************************************/
void digitalToggle(int pin);

changing this section of LilyGo-T-Connect-Pro.yaml to:
board_name: "LilyGo T-Connect Pro"

  # Interfaces GPIOs
  # uart_esp_1: RS485
  tx_pin_1: '17'
  rx_pin_1: '18'
  # canbus_esp32_can: CAN
  tx_pin_2: '15'
  rx_pin_2: '16'

Not sure how to specify SoftSerial on GPIO pins 1 and 2 so that the Victron Smart Shunt can be connected to its Rx pin.

[dlarue]

I created a new file and setup the UART for the Shunt on uart_esp1 but haven't worked out the EspSoftwareSerial issue yet.

https://github.com/dlarue/esphome-yambms/blob/446bb091b6245af017382508023c1b14d3e5249d/packages/board/board_ESP32-S3_WS-RS485-CAN.yaml

I did have a problem with the CAN device requiring a Light object be defined and I had to create a dummy light set to an unused pin. On the Waveshare module the LEDs are tied to the Tx and Rx pins so there is no direct pin control of an LED needed.

[Sleeper85]

I don't understand your problem with EspSoftwareSerial?

The three UARTs of an ESP32 can be assigned to the GPIOs of your choice, and they remain hardware UARTs.

I created the new ESP32-S3-RS485-CAN board.

Best regards

[dlarue]

The Waveshare ESP32-S3 RS485-CAN module is a custom product with an ESP32-S3 on it but it only exposes to the public nice wire screw terminals on one end for a CAN connection and an RS485 connection. The other side has a small 4 wire connector with a cable which brings out GPIO-1 and GPIO-2 pins along with GND and 3.3V. So in order to connect up the UART interface of a Victron Smart Shunt we need exposed UART pins and GPIO1/GPIO2 are not hardware UART pins. Hence the interest in a SoftwareSerial interface.

[Sleeper85]

As explained there is no soft uart with ESP32-S3, there are 3 hardware UARTs that you can connect to the GPIOs you want (with a few exceptions). I will modify the board to expose GPIOs 1 and 2.

[dlarue]

I didn't think so because I didn't find anything in the code defining a softwareserial interface. It's too bad Waveshare didn't provide a way to jumper other IO pins to those connector pins. Not everyone is comfortable messing with hardware and that's what makes this module so nice and it already comes in a protective case...
There is an onboard 20pin header which would likely allow for hardware UART access but would also require cutting holes in the case to get the wires out. Again, not a tough task for those who do this kind of thing but the 'software-only' crowd would likely walk away from that.

[Sleeper85]

What's stopping you from using GPIOs 1 and 2 for your shunt ?

Have you tried ?

Sorry but I still don't understand your problem...

I updated the board, you can use uart_esp_2 for the SH1.0 connector.

substitutions:
  board_chip: "ESP32-S3"
  board_name: "WS RS485-CAN"
  # Interfaces GPIOs
  # uart_esp_1               RS485 port (RS485_EN = GPIO 21)
  tx_pin_1: '17'
  rx_pin_1: '18'
  # uart_esp_2               SH1.0 connector
  tx_pin_2: '1'
  rx_pin_2: '2'
  # uart_esp_3               Pin header
  tx_pin_3: '3'
  rx_pin_3: '4'
  # canbus_esp32_can         CAN port
  tx_pin_4: '15'
  rx_pin_4: '16'
  # canbus_mcp2515
  spi_mosi_pin: '11'
  spi_miso_pin: '13'
  spi_clk_pin: '12'
  mcp2515_cs_pin: '10'

[dlarue]

I've not tried because I don't have the UART isolator yet and I was under the impression that a hardware UART device was IO pin specific unless stated in the documentation that they were remappable. THIS is the whole reason for mentioning the SoftwareSerial solution( a software defined UART device ) for IO1 and IO2 pins which are easily exposed for the none hardware types.

If you know that the hardware UART is remapped just by specifying the IO pins to use in the YAMBMS definitions then that's fantastic. We know there's another hardware UART but I'd thought it was dedicated to pins IO43 and IO44.

[Sleeper85]

Yes, since ESP32, the 3 UARTs can be mapped to the GPIOs of your choice. See the doc below. To free the 3rd UART assigned to logger, you must configure the baud_rate to 0, which is done in the YAML I posted.

https://esphome.io/components/uart/

[dlarue]

Dang, so what is all this talk about SoftwareSerial! Man, sorry about that. I don't recall if I knew that before and forgot it or I'm getting for the first time here

I was aware of the logger entry and used it in my device definition and even included other build specifics after testing using the Waveshare demo example and seeing their recommended SDK settings. I have it running YAMBMS as a 2nd node with no BMSs connected just to get Shunt data over BLE while waiting for the isolator. BTW, those other settings are PSRAM, flashsize, cachesize, SPIRAM, etc.
https://github.com/dlarue/esphome-yambms/blob/main/packages/board/board_ESP32-S3_WS-RS485-CAN.yaml

Seeing images like the following from searches for "esp32-s3 pinout" or any MCU pinout shows stuff like this with UART pins assigned. Good to know and thanks for importing or creating the WS RS485-CAN definition file.

[Sleeper85]

I looked yesterday but couldn't find anything.
Does this board really have PSRAM?
How much?

[dlarue]

I just saw that they specified to turn on and use OPI PSRAM options in the Arduino IDE. It was from there that I created the additional device sections. https://www.waveshare.com/wiki/ESP32-S3-RS485-CAN#Working_with_Arduino

[Sleeper85]

@GHswitt

I understand you ordered this board. There is no mention of PSRAM on Waveshare's website, let me know how it is when you test it.

[GHswitt]

@GHswitt

I understand you ordered this board. There is no mention of PSRAM on Waveshare's website, let me know how it is when you test it.

Will do. And check what RS485 transceiver is used. Because the one from the circuit diagram does not support Auto direction which would be unfortunate.

Edit: From the schematic it should be a ESP32-S3R8