Identifying TX/RX Pins on EWELINK Zigbee Gateway with ESP32 and EWL-WBT04 Module

Question

Hello, I am currently working on an EWELINK Zigbee gateway that uses an ESP32 chip. This device includes a module labeled EWL-WBT04, but I’ve been unable to find any documentation or information about it online. So far, I’ve successfully identified the GND and VCC pins. The module has a 2x9 pin...

miegapele · Answer

There is lots of different esp32 chips. If it's zigbee you probably should NOT try to flash it. Likely you will brick it.
If REALLY you want to try pinout looks similar to the one on page 13. pins 40 and 41.

inot · Answer

You can trace the path of the signals marked in the attachment. You can trace (traverse) the path of the signals marked in the attachment.

yotapaki · Answer

Thank you for your response!

The chip I’m working with is an ESP32 D0WD, which serves as a WiFi module. Additionally, the board includes another module featuring a Zigbee chip (CC2652).

I’ve managed to locate the TX and RX pins, and I’m trying to enter bootloader mode by grounding GPIO0. Unfortunately, it seems I don’t have direct access to this pin. Do you have any suggestions on how to proceed?

For reference, here’s some additional information that might help: https://kdrive.bagou450.com/app/share/763082/10c05739-3e48-4751-8a52-ee38994626ed

Apologies if my questions seem a bit basic—this is my first time working on something this advanced with a board! 😊

[url=https://obrazki.elektroda.pl/5718286300_1737102141.png] Close-up of a circuit board with marked pins GND, VCC, RX, and TX.

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inot · Answer

Proceed in the same way as before, i.e. find where the GPIO0 signal path leads.

yotapaki · Answer

I don’t fully understand how to proceed, as the GPIO pins seem to connect to another layer of the PCB.

However, I noticed that one pin switches from 3V to 0V when I press the button. Could this be GPIO0? I tried holding the button while powering it up, but instead of entering bootloader mode, it just boots normally.

inot · Answer

. This is most likely the CHIP_PU pin that serves as a reset. . I thought you knew what I meant by finding the TX and RX pins as I described. To check where the GPIO0 signal path goes, use a multimeter and measure whether there is a connection between it and the other pins (one of the eighteen).

insmod · Answer

>>21395282 I received that gateway today, and managed to flash and connect it to Z2M successfully.

For pins, treat it like ZBBridge-P that lack some features (i2c rtc, buzzer).
There is also a PSRAM chip that i haven't managed to get to work.
ESP32 backup attached.

insmod · Answer

And now i've managed to enable PSRAM by doing some pin tracing.
ESPHome sdkconfig_options are
CONFIG_D0WD_PSRAM_CLK_IO: "5"
CONFIG_D0WD_PSRAM_CS_IO: "18"

I haven't seen any config for ZBBridge-P with psram enabled, but since all pins are the same those would probably work for ZBBridge-P too.

divadiow · Answer

didn't know there was a thread for this already. mine arrived today too. more pics for library: Added after 37 [minutes]:log from that TX labelled. 115200 then 921600 Code: TextLog in, to see the code

setum · Answer

deleted, wrong thread

setum · Answer

>>21454302
Your mention of ESPHome got me intrigued. Can we install ESPHome in it? How will it work -- similar to Tasmota ZBBridge or similar to ESPHome bluetooth proxy, but with Zigbee (Zigbee Proxy). Do you have the ESPHome yaml for this device?

insmod · Answer

>>21487393
I don't know how Tasmota works - i've never used it.
But it creates a port for zigbee connection, and i use bluetooth proxy of course.
Connecting to zigbee is simple - just specify tcp://{ip}:8888
I tested this with Z2M, and now it works with ZHA.
I migrated from Tuya WRG1+TYZS3 gateway, flashed with OpenBeken to this.

I swapped led functions, now red - zigbee connection, blue - wifi status led.
Remove packages and specify your wifi, api and ota settings.

substitutions:
  ip: "192.168.0.9"
  powersave: "LIGHT"

esphome:
  name: esp32-zb-bridge
  friendly_name: esp32_zb-bridge
  platformio_options:
    build_flags: "-DBOARD_HAS_PSRAM"
  on_boot:
    priority: 800
    then:
      - switch.turn_on: zigbee_rst
      - delay: 15ms
      - switch.turn_off: zigbee_rst

external_components:
  - source: github://oxan/esphome-stream-server

esp32:
  board: esp32dev
  framework:
    type: esp-idf
    sdkconfig_options:
      CONFIG_ESP32_REV_MIN_3_1: "y"
      CONFIG_D0WD_PSRAM_CS_IO: "18"
      CONFIG_D0WD_PSRAM_CLK_IO: "5"
      CONFIG_BT_BLE_DYNAMIC_ENV_MEMORY: "y"
      CONFIG_BT_ALLOCATION_FROM_SPIRAM_FIRST: "y"

debug:
  update_interval: 5s

# Enable logging
logger:
  baud_rate: 115200 

uart:
  rx_pin: GPIO23
  tx_pin: GPIO19
  baud_rate: 115200

packages:
  common: !include base/common.yaml
  ota: !include base/ota.yaml
  wifi: !include base/wifi_psk_both.yaml

psram:
  mode: quad
  speed: 80MHz

esp32_ble_tracker:
  scan_parameters:
    interval: 1100ms
    window: 1100ms
    active: false

bluetooth_proxy:
  active: false
  cache_services: false

status_led:
  pin: 
    number: 21
    inverted: false

stream_server:
  port: 8888

binary_sensor:
  - platform: stream_server
    connected:
      name: Connected
      on_press:
        - light.turn_on: red
      on_release:
        - light.turn_off: red

  - platform: gpio
    pin: 
      number: 27
      inverted: True
    name: "update_switch"
    internal: True
    device_class: update
    on_click:
      min_length: 1s
      max_length: 3s
      then:
        - switch.turn_on: reboot
    on_double_click:
      min_length: 50ms
      max_length: 350ms
      then:
        - switch.turn_on: fw_update

sensor:
  - platform: stream_server
    connection_count:
      name: Number of connections
  - platform: debug
    free:
      name: "Heap Free"
    psram:
      name: "Free PSRAM"
  - platform: wifi_signal
    name: WiFi Signal Sensor
    update_interval: 3600s

output:
  - platform: gpio
    pin: GPIO2
    inverted: true
    id: status

light:
  - platform: binary
    name: "Red"
    id: red
    output: status
    internal: True
    restore_mode: ALWAYS_OFF

switch:
  - platform: template
    name: FW Update
    id: fw_update
    turn_on_action:
      - switch.turn_on: zigbee_bsl
      - delay: 1s
      - switch.turn_on: zigbee_rst
      - delay: 1s
      - switch.turn_off: zigbee_rst
      - delay: 2s
      - switch.turn_off: zigbee_bsl
      - delay: 25s
      - switch.turn_off: fw_update

  - platform: gpio
    id: zigbee_rst
    pin: 15
    name: "Zigbee RST"
    inverted: True
    internal: True
    restore_mode: ALWAYS_OFF

  - platform: gpio
    id: zigbee_bsl
    pin: 22
    name: "Zigbee BSL"
    inverted: True
    internal: True
    restore_mode: ALWAYS_OFF

tepliukyurii · Answer

Wgrałem oprogramowanie że zmieniłem firmware zigbee na coordinator od tasmota.Z Home Assistant pracuję jak z Z2M tak i ZHA.Dużo dodatkowych funkcji.

sevenissimo · Answer

>>21487805
Just wanted to let you know your post and all your work were an immense help! I easily managed to flash ESPHome onto my gateway, so huge thanks for that!

Unfortunately, Zigbee isn't working yet.
I'm guessing I need to upload the proper firmware, similar to other CCxxxx-based coordinators.
I'm just not clear if you did that step, and if so, which firmware version you used.

insmod · Answer

>>21558029 I used this: Firmware (flash only those, and not generic ones): Tool with guide: Make sure to toggle FW Update switch

sevenissimo · Answer

>>21558442 Thanks! I finally uploaded the Zigbee firmware and got ZHA working with this coordinator. The hardware seems like good value for money. It should be listed on blakadder.

germansunza · Answer

Hello, I hope you can help me. My English is not good. I have received my gateway and connected it as shown in the image, but I can't get any data. It seems that the TX and RX pins are not correct.

insmod · Answer

>>21582439
They cannot be wrong, i've traced them and flashed successfully via them.
Perhaps you've accidentally swapped RX and TX? And as far as i remember, they aren't used for logging, so don't expect any output.

germansunza · Answer

>>21582540 Connect the module's RX to the UART's TX and TX to RX. I tried to flash it with Tasmota and without success. I tried to do it with Esphome using the script you posted and the same result, GPIO to ground to be able to enter programming mode, voltage at 3.3 volts.

insmod · Answer

I was using usb to power it, and connecting uart module gnd to any gnd on the whole board (even usb socket body would work). GPIO0 to gnd before powering up.
Alternatively you could try to read/write firmware via ch341a and a clip.

germansunza · Answer

>>21583025 In the end it was my USB adapter, I managed to flash it with Tasmota and it's working fine for the moment.

Identifying TX/RX Pins on EWELINK Zigbee Gateway with ESP32 and EWL-WBT04 Module

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