Hello,
I have two Tuya 20A Power Monitoring Plug (AJW-02_8285) on Tasmota that I would like to migrate to ESPHome. Theses plugs use a BL0937 chip for power monitoring and my problem is that I don’t know wich pins to set for CF1 and SEL since in Tasmota, I only have to set the CF pin. The hlw8012 esphome component seem required at least the 3 pins but Tasmota seem known how to works with only one. Their is a way to configure ESPhome hlw8012 component with only the CF pin ?
Thanks !
I know nothing about the plug you have … however I have 5 of “Arlec PC191HA smart plugs with Energy Monitoring” which I have converted some to ESPhome. They also use the BL0937 chip for power monitoring.
I don’t know if it will be relevant to you … I guess it depends on whether this describes the BL0937 chip itself or the hardware/firmware of my PC191HA devices. Anyway, the information I gleaned in research for my devices indicates:
My work-around is to keep SEL set to VOLTAGE, and calculate Current from Power and Volts.This is the part of my ESPhome yaml file relating to power monitoring. Hopefully it might also be relevant to you.
#
# PC191HA sensors - power monitoring
#
sensor:
# PC191HA includes a BL0937 chip for measuring power consumption
# and BL0937 is a variation of hlw8012, but using inverted SEL pin functionality
- platform: hlw8012
model: BL0937 # note that the model must be specified to use special calculation parameters
sel_pin: # I believe that cf_pin reports either Voltage or Current depending on this select pin
inverted: true # determine whether true reports Voltage
number: P24
cf_pin: # current or voltage (ele_pin: 7)
inverted: true # the logic of BL0937 is opposite from HLW8012
number: P7
cf1_pin: # Power (vi_pin: 8)
inverted: true # the logic of BL0937 is opposite from HLW8012
number: P8
update_interval: "30s" # How often to measure and report values
# PC191HA measures and returns Voltage OR Current according to the value of sel_pin,
# but it can change the value of sel_pin periodically
initial_mode: "VOLTAGE" # reports VOLTAGE or CURRENT
change_mode_every: "4294967295" # do NOT swap between reporting Volts or Amps (well, swap after 4000 years)
# reporting Voltage or Current. Note that the first value reported should be ignored as inaccurate
# Adjust according to the actual resistor values on board to calibrate the specific unit
voltage_divider: "775" # LOWER VALUE GIVES LOWER VOLTAGE
current_resistor: "0.0009" # HIGHER VALUE GIVES LOWER WATTAGE
# how the power monitoring values are returned to ESPHome
voltage:
name: $friendly_name Voltage
id: ${name}_voltage
unit_of_measurement: V
accuracy_decimals: 1
filters:
- skip_initial: 2
power:
name: $friendly_name Power
id: ${name}_power
unit_of_measurement: W
accuracy_decimals: 2
filters:
- skip_initial: 2
# power is simply current x voltage -- except that the pc191ha doesn't follow that formula.
# Setting current_resistor to give an accurate Amperage does NOT also give the correct Wattage
# my work-around is to calculate current from power / voltage
- platform: template
name: $friendly_name Current
id: ${name}_current
unit_of_measurement: A
accuracy_decimals: 2
update_interval: "30s"
lambda: |-
return (id(${name}_power).state / id(${name}_voltage).state);
filters:
- skip_initial: 5 # give time for data to settle to avoid NaN
Hey @donburch would you mind sharing your full ESPHome config for the PC191HA plug? I have cloud cut mine but struggling to figure out the correct pins etc…
I am most glad to, but may be more relevant in the Energy consumption and Arlec Grid Connect (Tuya) smart plug - #71 by donburch888 thread.
With some last hints about the correct pins found in the example from @donburch888 I was able to get my similar smartplug to work and report the energy (need to calibrate but getting values now 
).
For others that are searching for the correct config. Next yaml is working for my SmartPlug (https://nl.aliexpress.com/item/4000060646437.html visual similar to the one of @brenard ). The main chip is a bk7231t qfn32 with a BL0937 energy monitor. The back of the main board also has the label LSP16DL.
substitutions:
devicename: smartplug
friendly_name: My plug
device_description: My plug description
current_res: "0.00221" # Power monitoring calibration
voltage_div: "955" # Power monitoring calibration
esphome:
name: ${devicename}
friendly_name: ${friendly_name}
comment: ${device_description}
bk72xx:
board: generic-bk7231t-qfn32-tuya
# Enable logging
logger:
# Enable Home Assistant API
api:
encryption:
key: !secret api_encryption
ota:
password: !secret ota_password
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
# Enable fallback hotspot in case wifi connection fails
ap:
ssid: ${friendly_name} Fallback Hotspot
password: !secret wifi_ap_password
# Enable time component for use by daily power sensor
time:
- platform: homeassistant
id: homeassistant_time
sensor:
# Reports how long the device has been powered (in minutes)
- platform: uptime
name: Uptime
filters:
- lambda: return x / 60.0;
unit_of_measurement: minutes
# Reports the WiFi signal strength
- platform: wifi_signal
name: Wifi Signal
update_interval: 60s
# Reports the Current, Voltage, and Power used by the plugged-in device
- platform: hlw8012
model: BL0937
sel_pin:
number: GPIO24
inverted: true
cf_pin:
number: GPIO7
inverted: true
cf1_pin:
number: GPIO8
inverted: true
change_mode_every: 8
update_interval: 5s
current:
name: Current
icon: mdi:current-ac
unit_of_measurement: A
voltage:
name: Voltage
filters:
- skip_initial: 1
power:
id: power
name: Power
filters:
- skip_initial: 1
- multiply: 0.97
- lambda: if (x < 0.01) {return 0;} else {return x;}
energy:
name: Energy
filters:
- skip_initial: 1
current_resistor: ${current_res}
voltage_divider: ${voltage_div}
# Reports the total Power so-far each day, resets at midnight, see https://esphome.io/components/sensor/total_daily_energy.html
- platform: total_daily_energy
name: Total Daily Energy
icon: mdi:circle-slice-3
power_id: power
filters:
# Multiplication factor from W to kW is 0.001
- multiply: 0.001
unit_of_measurement: kWh
binary_sensor:
# Button on the front is pressed and then toggle relay
- platform: gpio
device_class: power
pin:
number: GPIO10
mode: INPUT_PULLUP
inverted: True
name: Button # Name to make button visible in HA
on_press:
- switch.toggle: relay
text_sensor:
# Reports the ESPHome Version with compile date
- platform: version
name: ESPHome Version
- platform: libretiny
version:
name: LibreTiny Version
# Reports detailed wifi info, can be commented out
- platform: wifi_info
ip_address:
name: IP Address
# ssid: # Some additional wifi info that is not normally needed
# name: Connected SSID
# bssid:
# name: Connected BSSID
switch:
# Relay itself
- platform: gpio
name: ${friendly_name}
pin: GPIO26
id: relay
restore_mode: RESTORE_DEFAULT_OFF #Try to restore relay state after reboot/power-loss event.
#RESTORE_DEFAULT_OFF (Default) - Attempt to restore state and default to OFF if not possible to restore. Uses flash write cycles.
#RESTORE_DEFAULT_ON - Attempt to restore state and default to ON. Uses flash write cycles.
#ALWAYS_OFF - Always initialize the pin as OFF on bootup. Does not use flash write cycles.
#ALWAYS_ON - Always initialize the pin as ON on bootup. Does not use flash write cycles.