Hello, this is a brief manual how to integrate Caperplus Q2 pH & TDS meter to HA.
As mentioned in another forum there is probably a possibility to sniff data between the device and mobile app, however I wasn’t able to do that, so I decided to flash onboard esp - for this purpose basic soldering skills and soldering iron pen type with a conical/sharp tip are required.
At first, to create original firmware backup and flash onboard ESP-12F, I soldered pins as described on this site and I used CP2102 USB-UART converter:
To create original firmware backup I used esptool with command (replace PORT for yours PORT of connected converter):
esptool -p PORT -b 460800 read_flash 0 0x400000 caperplus-orig.bin
Then I flashed esp with following code based on this configuration which also uses this library to decode data. Mentioned caperplus_q2_uart_sensor.h library need to be uploaded first to yours /homeassistant/esphome/ localization before code compilation.
esphome:
name: esp-caperplus-q2
friendly_name: esp-caperplus-q2
includes:
- ./caperplus_q2_uart_sensor.h
esp8266:
board: d1_mini
# Enable logging
logger:
baud_rate: 0 #disable logging over uart
# Enable Home Assistant API
api:
encryption:
key: "***"
ota:
- platform: esphome
password: "***"
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
# Enable fallback hotspot (captive portal) in case wifi connection fails
ap:
ssid: "Esp-Caperplus-Q2"
password: "***"
captive_portal:
uart:
id: uart_bus
rx_pin: GPIO3
parity: NONE
data_bits: 8
stop_bits: 1
baud_rate: 9600
sensor:
- platform: custom
lambda: |-
auto caper = new CaperPlusQ2UartSensor(id(uart_bus));
App.register_component(caper);
return {caper->temperature_sensor, caper->ph_sensor, caper->tds_sensor};
sensors:
- name: "Temperature"
unit_of_measurement: "°C"
accuracy_decimals: 1
state_class: measurement
device_class: temperature
- name: "pH"
unit_of_measurement: "pH"
icon: mdi:ph
accuracy_decimals: 2
state_class: measurement
- name: "TDS"
unit_of_measurement: "ppm"
accuracy_decimals: 0
state_class: measurement
After flashing onboard esp, desoldering pins and powering device, it appears in HA 
Logs esp-caperplus-q2.yaml
INFO ESPHome 2024.12.2
INFO Reading configuration /config/esphome/esp-caperplus-q2.yaml...
INFO Starting log output from 192.168.1.144 using esphome API
INFO Successfully connected to esp-caperplus-q2 @ 192.168.1.144 in 0.006s
INFO Successful handshake with esp-caperplus-q2 @ 192.168.1.144 in 2.370s
[14:24:15][I][app:100]: ESPHome version 2024.12.2 compiled on Dec 27 2024, 11:00:18
[14:24:15][C][wifi:600]: WiFi:
[14:24:15][C][wifi:428]: Local MAC: EC:64:C9:FC:CD:0E
[14:24:15][C][wifi:433]: SSID: [redacted]
[14:24:15][C][wifi:436]: IP Address: 192.168.1.144
[14:24:15][C][wifi:439]: BSSID: [redacted]
[14:24:15][C][wifi:441]: Hostname: 'esp-caperplus-q2'
[14:24:15][C][wifi:443]: Signal strength: -56 dB ▂▄▆█
[14:24:15][C][wifi:447]: Channel: 1
[14:24:15][C][wifi:448]: Subnet: 255.255.255.0
[14:24:15][C][wifi:449]: Gateway: 192.168.1.1
[14:24:15][C][wifi:450]: DNS1: 192.168.1.1
[14:24:15][C][wifi:451]: DNS2: 0.0.0.0
[14:24:15][C][logger:185]: Logger:
[14:24:15][C][logger:186]: Level: DEBUG
[14:24:15][C][logger:188]: Log Baud Rate: 0
[14:24:15][C][logger:189]: Hardware UART: UART0
[14:24:15][C][uart.arduino_esp8266:118]: UART Bus:
[14:24:15][C][uart.arduino_esp8266:120]: RX Pin: GPIO3
[14:24:15][C][uart.arduino_esp8266:122]: RX Buffer Size: 256
[14:24:15][C][uart.arduino_esp8266:124]: Baud Rate: 9600 baud
[14:24:15][C][uart.arduino_esp8266:125]: Data Bits: 8
[14:24:15][C][uart.arduino_esp8266:126]: Parity: NONE
[14:24:15][C][uart.arduino_esp8266:127]: Stop bits: 1
[14:24:15][C][uart.arduino_esp8266:129]: Using hardware serial interface.
[14:24:15][C][captive_portal:089]: Captive Portal:
[14:24:15][C][mdns:116]: mDNS:
[14:24:15][C][mdns:117]: Hostname: esp-caperplus-q2
[14:24:15][C][esphome.ota:073]: Over-The-Air updates:
[14:24:15][C][esphome.ota:074]: Address: esp-caperplus-q2.local:8266
[14:24:15][C][esphome.ota:075]: Version: 2
[14:24:15][C][esphome.ota:078]: Password configured
[14:24:15][C][safe_mode:018]: Safe Mode:
[14:24:15][C][safe_mode:019]: Boot considered successful after 60 seconds
[14:24:15][C][safe_mode:021]: Invoke after 10 boot attempts
[14:24:15][C][safe_mode:022]: Remain in safe mode for 300 seconds
[14:24:15][C][api:140]: API Server:
[14:24:15][C][api:141]: Address: esp-caperplus-q2.local:6053
[14:24:15][C][api:143]: Using noise encryption: YES
[14:24:20][D][caperplus-q2:094]: Available bytes: 62
[14:24:20][D][caperplus-q2:100]: Found header!
[14:24:20][D][caperplus-q2:115]: pH: 9.16
[14:24:20][D][caperplus-q2:116]: TDS: 0
[14:24:20][D][caperplus-q2:117]: Temp: 21.8
[14:24:20][D][sensor:093]: 'Temperature': Sending state 21.80000 °C with 1 decimals of accuracy
[14:24:20][D][sensor:093]: 'pH': Sending state 9.16000 pH with 2 decimals of accuracy
[14:24:20][D][sensor:093]: 'TDS': Sending state 0.00000 ppm with 0 decimals of accuracy
[14:24:20][D][caperplus-q2:065]: Clearing Serial Buffer
[14:24:20][D][caperplus-q2:094]: Available bytes: 62
[14:24:20][D][caperplus-q2:100]: Found header!
[14:24:20][D][caperplus-q2:115]: pH: 9.16
[14:24:20][D][caperplus-q2:116]: TDS: 0
[14:24:20][D][caperplus-q2:117]: Temp: 21.8
[14:24:20][D][sensor:093]: 'Temperature': Sending state 21.80000 °C with 1 decimals of accuracy
[14:24:20][D][sensor:093]: 'pH': Sending state 9.16000 pH with 2 decimals of accuracy
[14:24:20][D][sensor:093]: 'TDS': Sending state 0.00000 ppm with 0 decimals of accuracy
[14:24:20][D][caperplus-q2:065]: Clearing Serial Buffer
[14:24:20][D][caperplus-q2:094]: Available bytes: 62
[14:24:20][D][caperplus-q2:100]: Found header!
[14:24:20][D][caperplus-q2:115]: pH: 9.16
[14:24:20][D][caperplus-q2:116]: TDS: 0
[14:24:20][D][caperplus-q2:117]: Temp: 21.8
[14:24:20][D][sensor:093]: 'Temperature': Sending state 21.80000 °C with 1 decimals of accuracy
[14:24:20][D][sensor:093]: 'pH': Sending state 9.16000 pH with 2 decimals of accuracy
[14:24:20][D][sensor:093]: 'TDS': Sending state 0.00000 ppm with 0 decimals of accuracy
[14:24:20][D][caperplus-q2:065]: Clearing Serial Buffer
To clear your doubts:
- Caperplus mobile app is no longer working
- physical calibration button still works as designed
Good luck!