When connected together I’am not able to read from PZEM’s
Have assigned unique ID’s for all 3 PZEMs
Individually, I’m able to read them in their respective IDs
But when connected altogether, they are not working
One observation from PZEM LED status is that all PZEMs transmit together, same with receiving too
Hardware Setup
Wemos D1 Mini
PZEMs are directly connected to TX-RX (parallel connection with no pullup resistor or diode)
Any support will be invaluable 
Full code below
substitutions:
devicename: 3phase-power-monitor
friendly_name: Power Monitor
esphome:
name: ${devicename}
friendly_name: ${friendly_name}
name_add_mac_suffix: false
project:
name: esphome.web
version: "1.0"
esp8266:
board: esp01_1m
logger:
baud_rate: 0 # free UART for PZEM
level: DEBUG # change to INFO later
wifi:
ssid: !secret wifi_id
password: !secret wifi_pw
ap:
ssid: $devicename
password: "1122334455"
ota:
- platform: esphome
api:
web_server:
port: 80
version: 3
dashboard_import:
package_import_url: github://esphome/example-configs/esphome-web/esp8266.yaml@main
import_full_config: true
time:
- platform: homeassistant
id: homeassistant_time
uart:
tx_pin: GPIO1
rx_pin: GPIO3
baud_rate: 9600
stop_bits: 1
parity: NONE
# Increased modbus timing to prevent bus contention
modbus:
id: mod_bus_pzem
send_wait_time: 2000ms # 2 seconds between requests
binary_sensor:
- platform: status
name: "${devicename} Status"
text_sensor:
- platform: wifi_info
ip_address:
name: "${devicename} IP Address"
ssid:
name: "${devicename} Connected SSID"
mac_address:
name: "${devicename} MAC Address"
sensor:
- platform: wifi_signal
name: "${devicename} WiFi Signal"
update_interval: 60s
- platform: uptime
name: "${devicename} Uptime"
# --------- PHASE L1 ----------
- platform: pzemac
id: pzemac1
address: 1
modbus_id: mod_bus_pzem
update_interval: 90s # Long interval, controlled by automation
current:
name: "Current L1"
id: current_l1
voltage:
name: "Voltage L1"
id: voltage_l1
energy:
name: "Energy L1"
id: energy_l1
device_class: energy
state_class: total_increasing
unit_of_measurement: "Wh"
power:
name: "Power L1"
id: power_l1
device_class: power
state_class: measurement
frequency:
name: "Frequency L1"
id: frequency_l1
power_factor:
name: "Power Factor L1"
id: pf_l1
# --------- PHASE L2 ----------
- platform: pzemac
id: pzemac2
address: 2
modbus_id: mod_bus_pzem
update_interval: 90s
current:
name: "Current L2"
id: current_l2
voltage:
name: "Voltage L2"
id: voltage_l2
energy:
name: "Energy L2"
id: energy_l2
device_class: energy
state_class: total_increasing
unit_of_measurement: "Wh"
power:
name: "Power L2"
id: power_l2
device_class: power
state_class: measurement
frequency:
name: "Frequency L2"
id: frequency_l2
power_factor:
name: "Power Factor L2"
id: pf_l2
# --------- PHASE L3 ----------
- platform: pzemac
id: pzemac3
address: 3
modbus_id: mod_bus_pzem
update_interval: 90s
current:
name: "Current L3"
id: current_l3
voltage:
name: "Voltage L3"
id: voltage_l3
energy:
name: "Energy L3"
id: energy_l3
device_class: energy
state_class: total_increasing
unit_of_measurement: "Wh"
power:
name: "Power L3"
id: power_l3
device_class: power
state_class: measurement
frequency:
name: "Frequency L3"
id: frequency_l3
power_factor:
name: "Power Factor L3"
id: pf_l3
# --------- DAILY ENERGY PER PHASE (kWh) ----------
- platform: total_daily_energy
name: "Energy L1 Daily"
power_id: power_l1
id: energy_l1_daily
unit_of_measurement: kWh
accuracy_decimals: 3
filters:
- multiply: 0.001
- platform: total_daily_energy
name: "Energy L2 Daily"
power_id: power_l2
id: energy_l2_daily
unit_of_measurement: kWh
accuracy_decimals: 3
filters:
- multiply: 0.001
- platform: total_daily_energy
name: "Energy L3 Daily"
power_id: power_l3
id: energy_l3_daily
unit_of_measurement: kWh
accuracy_decimals: 3
filters:
- multiply: 0.001
# --------- CALCULATED TOTAL SENSORS ----------
- platform: template
name: "Total Power"
id: total_power
device_class: power
state_class: measurement
unit_of_measurement: W
accuracy_decimals: 1
update_interval: 30s
lambda: |-
float p1 = id(power_l1).state;
float p2 = id(power_l2).state;
float p3 = id(power_l3).state;
if (isnan(p1) || isnan(p2) || isnan(p3)) {
return NAN;
}
return p1 + p2 + p3;
- platform: template
name: "Total Energy"
id: total_energy
device_class: energy
state_class: total_increasing
unit_of_measurement: kWh
accuracy_decimals: 3
update_interval: 30s
lambda: |-
float e1 = id(energy_l1).state;
float e2 = id(energy_l2).state;
float e3 = id(energy_l3).state;
if (isnan(e1) || isnan(e2) || isnan(e3)) {
return NAN;
}
float total_wh = e1 + e2 + e3;
return total_wh * 0.001;
- platform: template
name: "Total Daily Energy"
id: total_energy_daily
device_class: energy
state_class: total_increasing
unit_of_measurement: kWh
accuracy_decimals: 3
update_interval: 30s
lambda: |-
float e1 = id(energy_l1_daily).state;
float e2 = id(energy_l2_daily).state;
float e3 = id(energy_l3_daily).state;
if (isnan(e1) || isnan(e2) || isnan(e3)) {
return NAN;
}
return e1 + e2 + e3;
button:
- platform: restart
name: "${devicename} Restart"
- platform: template
name: "Reset Energy L1"
on_press:
then:
- pzemac.reset_energy: pzemac1
- platform: template
name: "Reset Energy L2"
on_press:
then:
- pzemac.reset_energy: pzemac2
- platform: template
name: "Reset Energy L3"
on_press:
then:
- pzemac.reset_energy: pzemac3
# SEQUENTIAL POLLING - Critical fix for bus contention
# Poll Phase 1 every 30 seconds
interval:
- interval: 30s
then:
- component.update: pzemac1
# Poll Phase 2 every 30 seconds, but offset by 10 seconds
- interval: 10s
then:
- delay: 10s
- component.update: pzemac2
# Poll Phase 3 every 30 seconds, but offset by 20 seconds
- interval: 20s
then:
- delay: 20s
- component.update: pzemac3
