Esp32 C3 Zero Epever Modbus Register 36965: Length of night-mins
Technical documentation for Modbus register 36965 on Esp32 C3 Zero Epever. Data type: U WORD. Includes Python and YAML configuration examples.
January 16, 2026
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1 min read
Technical Definition
The register Length of night-mins at address 36965 is used to monitor length of night-mins on the Esp32 C3 Zero Epever.
- Protocol: Modbus RTU
- Data Type: U WORD
- Unit: m
- Access: Read Only
How to Read (Python pymodbus)
Use this code snippet to read this specific value via RS485:
from pymodbus.client.sync import ModbusSerialClient
client = ModbusSerialClient(method='rtu', port='/dev/ttyUSB0', baudrate=9600)
client.connect()
# Read Length of night-mins (Address: 36965)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=36965, count=2, unit=1)
if not result.isError():
print(f"Raw Value: {result.registers}")
else:
print("Error reading register")
client.close()
Integration (Home Assistant)
Paste this into your configuration.yaml:
- platform: modbus_controller
name: "Length of night-mins"
address: 36965
value_type: U_WORD
unit_of_measurement: "m"
Connection Diagram
Here is the standard RS485 wiring for this configuration:
graph TD
PLC[Host Controller / Home Assistant]
Device[Esp32 C3 Zero Epever]
PLC -- "A+ (D+)" --> Device
PLC -- "B- (D-)" --> Device
PLC -- GND --> Device
💡 Engineer's Insight
Analysis: Duration of the nighttime period in minutes. Used for device operation scheduling.
Troubleshooting: Zero indicates no defined nighttime, possibly due to incorrect configuration or sensor failure.