Hi @nabucco
the dwm_usr_data_read/write are meant to be used with tag/angor to communicate with the gateway/ MQTT. There is no way how to read data IoT data from Anchor in passive mode (Listener).
But there is a way how to read IoT data from the node in bridge configuration. Check the documentation “DWM1001 Firmware API Guide” - Chapter 3 API operation flow + Chapter 5.4 Backhaul API Functions. However implementing this clockwork is not an easy task. Much easier is to put there Raspberry PI which will handle this.
Cheers,
JK