Hello everyone,
I am using the RFM69HW module (and RFM69 library) for a new project I'm working on (first experience with this 433 MHz modules). I have sending/receiving problems due to low signal. The RSSI is on both ends between -105 to -90 dBm.
Test setup for both end devices:
- RFM69HW 433Mhz with wire antenna 1/4 lambda (173 mm).
- my RFM breakout board with 47uF capacitor (simple board used to connect the 2.0 mm spaced pins to typically 2.54 mm space pinhead for Arduino). The antenna pin left out. The wire is connected directly to the RFM.
- Arduino Pro Mini 3.3V (with no led's and no voltage regulator).
- FTDI breakout board 3.3V - used for debugging and power up the arduino and transceiver.
The distance between the transceivers is about 1 - 1.5 meters.
In order to be shure that I am not doing something wrong, I used the Struct_receive/Struct_send examples from
https://github.com/LowPowerLab/RFM69/tree/master/Examples, slightly modified the code for different test cases:
Case 1: Code as github.
Struct_receive: RSSI between -105 to -90
Struct_send: RSSI between -105 to -90
I tried also with more than 10m distance and through 1 wall, transceiver is losing messages but the RSSI remains the same.
Case 2: IS_RFM69HW_HCW line commented out on both ends
Struct_receive: RSSI of -85 to -77
Struct_send: RSSI of -85 to -76
Both ends lose a lot of messages. Maybe 2 from 10 (20%) of the messages were received.
Case 3: IS_RFM69HW_HCW line commented out on only on Struct_receive
Struct_receive: RSSI of -22 to -28
Struct_send: RSSI of -105 (time to time)
Struct_Send does not receive the ack that the messages have arrived (console message: "...nothing...")
Case 4: IS_RFM69HW_HCW line commented out on only on Struct_send
Struct_receive: does not receive anything
Struct_send: does not receive ack
I have also tried all the cases with 2 new transceivers, 4 transceivers in rotation (each one tested with each other), wire antenna both 173 and 165 mm long, also tried both ends powered over power supply (in case of current issues)...
Does someone experienced the same thing?
Is there something I am doing wrong?
Can it happen that, if the seller sent me the RFM69W and leave the definition IS_RFM69HW_HCW uncommented the transceiver will get damaged?
I have also attached one image of the RFM69 I have...
Can someone help me with this issue?
Thanks!