Other Parts Discussed in Thread: CC1310
Hey guys,
we currently have 29 sensor nodes (TIDA 00489 design) and one CC1310 launchpad as collector connected to a raspberry pi. We use the sensor collector example based on the SDK 2.4.
Each 5 mins, the sensors send their data, a 2 byte long integer, to the collector. The collector receives the data and prints it to UART so the Raspi can read it. Additionally, we have a sniffer installed checking the whole traffic. The sniffer is lying directly next to the collector. Note, that the maximum number of retries if a message was not acknowledged by the collector is 3.
Setup 1: The sensors are on a table, the collector is lying on the floor with a distant of 3m to the sensors in an office room.
Setup 2: The Collector is lying on a table next to the sensors, approx. 1m distance.
Setup 3: The sensors are placed in another room so they have to pass 3 walls (approx. 25m of total distance)
Observations:
- Setup 1: The data send of several sensors is not acknowledged by the collector even after 3 retries of the sensor, no acknowledge from the collector. Sometimes the second or the third try of the sensors is acknowledged.
- Setup 2: Approximately 90% of the data is acknowledged immediately by the collector. The other 10% after the second or third retry.
- Setup 3: A few sensors still get acknowledged all the time, most of the others are not acknowledged anymore.
For all setups, the RSSI value measured by the sniffer is not a criteria if the collector acknowledges the message or not. For setup 1 and 2 its -40 to -60 dbm, for setup 3 its around -80 to -90dbm. Sometimes messages with slightly lower RSSI get acknowledged and others not.
Questions:
What could be the reason, that some sensors are have bad acknowledgement rates compared to others, when the distance is increased? (all suggestions welcome)
And why are there performance issues even if the sensors are only 1m away and why is that so randomly?
Kind regards
Slev1n