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US 240V Clothes Dryer PZEM004T Energy Monitor

Michael Ingraham edited this page Mar 2, 2019 · 5 revisions

The PZEM-004T together with a HW-655 Relay provide a good clamp-on energy monitor for a 240V clothes dryer.

Parts needed


Install TASMOTA (requires 2.4.2 ESP Core or higher) on the ESP-01 and confirm it is functional before connecting the PZEM-004T to its serial interface.

Hardware connections

Connect the serial interface of the HW-655 with the serial interface of the PZEM-004T.

As most parts are connected to high voltage AC it is recommended to fit the hardware in a solid enclosure.

Software configuration

Module Template
{"NAME":"HW-655 PZEM","GPIO":[0,63,0,62,0,0,0,0,0,0,0,0,0],"FLAG":0,"BASE":18}

Use the module template to configure the GPIO's for hardware serial connection.

IMPORTANT: If using the connections as following, the communication works in all cores due to TASMOTA using hardware serial. If the user wants to use other GPIOs for communication, TASMOTA will emulate a serial interface using software serial. This feature does not work using core 2.3.0 due to insufficient RAM. To use the software serial feature, please compile using core 2.4.2 or greater.


Per Theo - As the PZEM is a dedicated energy monitor, device calibration in TASMOTA is currently not supported.

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