cc2538 range problem

Hi dear Riot community, I have a problem with my Zolertia Re-Mote RevB.

I’m trying to send some Data via cc2538_rf but the range is somehow just 30 centimeters.

I had a similar situation by Contiki too but I realized that the radio frequency setting was still on <1Ghz (cc1200 setting) after I set it to 2.4 GHz it started working correctly.

I couldn’t find any documentation how to set the RF Freq. to 2.4 GHz. Actually, cc1200 is not been supported by Riot so I think that the rf frequency of Re-Mote RevB should be set on 2.4 GHz am I wrong?

Thank you in advance

Best, Kemal

Dear Community, I still have a problem to send data with the integrated RF Modul (CC2538) Zolertia Re-Mote Revb. The range is ~30 centimeters. Is there any known issue with this chip? Thank you

Best, Kemal

Dear Kemal,

there is a known issue with the CC2538 when packets need to be fragmented into several frames. Also there is currently no ACK handling in RIOT for the CC2538 transceiver, hence when sending too fast frames will likely get lost due to collision.

However, in general sending data should work (under constraints mentioned above). Please try the following: flash both Remotes with RIOTs `gnrc_networking` example, connect to their shells. Run `ping6 ff02::1` and see if you get something through, if not you may also try to increase tx power with `ifconfig 7 set power 7` (7 is the maximum for the remotes). Then try again to ping.

I just tested this with 2 remotes roughly set 30cm apart, too, and it worked - though there was some packet loss but pings got through. If that works for you as well, you can start UDP server on one RIOT node and send data from the other.

Btw. you may also add 2.4GHz antennas to increase gain, maybe that helps too.

Best,   Sebastian

Dear Sebastian, thank you very much for the detailed answer. I already tested its working better now.

I don’t want to bother you, but is there a way to get the details (like the dump when I type udp send fe80::212:4b00:14b5:f3da 8080 0x1[data]) actually the RSSI and LQI with UDP sock API (sock_udp_recv)? Best Regards, Kemal