DSMR Logger V4 (Smart Meter Reader)Placed on
data request circuit
For the "high" and "lowmaking the Data request pin of the Smart Meter I have tried different variants. With a combination of one or two transistors and/or MosFets I couldn't get it to work stably. In the end it is one optocoupler become.
Below is the schematic for the Data Request functionality:
The circuit is controlled from GPIO12 of the ESP8266 and ensures that at a “high” signal goes to the LED in the opto-coupler to burn.
This will cause the transistor “Close” (it will conduct) so that the 5Volt on the collector (pin5) ends up directly on the emitter (pin4) (it becomes “high”). This will also make DTR_SM “high” and the Smart Meter will send a telegram.