Difference in receiver sensibility CC1101 / SX127x

Theengs OpenMQTTGateway Radio frequencies gateways 315mhz, 433mhz, 868mhz
1

Hi there ,
i have 2 instances of OMG running, one on a Heltec lora V2 board , and the second one on an ESP32+CC1101 receiver.
Both firmware are compiled by my own with the dev branch , and the receiver are placed side by side in my home.
The result is that the Heltec is receiving more devices than the ESP+CC, as an example , i have 3 Nexus TH temp sensor , both 3 are received on the Heltec and only 2 on the ESP so i guess it’s not linked to some protocols decoding as both are using RTL_433 lib to decode .
Is there something i’m missing or there is indeed a diff in the receiver sensibility ?
Regards.

2

Hello,
to illustrate , here’s a scrrencap of the MQTT output where we can the sensors received on each devices , knowing that there are placed side by side .

Capture d’écran 2023-10-12 180459

3

Hello,

Other users had better results with the CC1101 using the esp32 platform 3.5.0 instead of 6.1.0 , could be an interesting try on your side:

4

Hello @1technophile and thanks for your feedback.
Indeed, i’ve seen this in the comments and i’m already using the 3.5.0 ESP32 platform with the 0.3.1 RTL_433 lib not directly for this sensibility concern but more for stability concern.
As you can see in the picture , my OMG is not a model in terms of stability ( i have an automatic reboot at 00:00 ) :grin:

Capture d’écran 2023-10-16 080522
Capture d’écran 2023-10-16 0805221616×434 63.8 KB

To come back to the original topic , so yes , i’m already using the 3.5.0 platform in both my Heltec and my ESP32 and i still have this receive difference.
Regards.

5

I gave up on the cc1101 tested for weeks and weeks, switched to the sx1276, much better reliability now. The cc1101 seems to have some bugs/plagued by old/reject/counterfeit chips or just really bad noise immunity and interference. I also switched to a tuned half wave antenna.

I also have the stability issue, I think its memory leaking, I have not found out from where, so added a reboot as you have. I also had to bump the rtl_433 buffer size or would get exceptions

6

Hello,
on my side , it seems that i’ve found a stability point by removing this device from the source and recompiling :

N: Send on /RTL_433toMQTT/GT-WT02/3/47 msg {"model":"GT-WT02","id":47,"channel":3,"battery_ok":1,"temperature_C":-101.8,"humidity":100,"button":0,"mic":"CHECKSUM","protocol":"Globaltronics GT-WT-02 Sensor","rssi":-69,"duration":944000}
CORRUPT HEAP: Bad head at 0x3ffe88f8. Expected 0xabba1234 got 0x4843223a

assert failed: multi_heap_free multi_heap_poisoning.c:253 (head != NULL)


Backtrace: 0x40083829:0x3ffe6760 0x4008d7bd:0x3ffe6780 0x400933a9:0x3ffe67a0 0x40092fff:0x3ffe68d0 0x40083ced:0x3ffe68f0 0x400933d9:0x3ffe6910 0x4012c799:0x3ffe6930 0x4012c7a9:0x3ffe6950 0x400db511:0x3ffe6970 0x400dbd7d:0x3ffe6a00 0x400dc56a:0x3ffe6a90 0x4012342d:0x3ffe6b70 0x401ce496:0x3ffe6bb0 0x40109ca2:0x3ffe6bd0 0x401249ff:0x3ffe6cb0 0x401253e1:0x3ffe6cd0 0x40123772:0x3ffe6d10 0x400f961b:0x3ffe6d40

Now both my heltec and cc1101 are quite stable , the can live all the day without any concerns.

1 Like
7

i got a lilygo LoRa v2.1 with a sx1278 and a generic ESP32 with a cc1101, both running the precompiled binary. same result, the sx127x finds much more sensors.
i will be happy if there is more support / bugfixing comming for the cc1101, as i really like OMG. So far i have to use binaries as self-compiling is over my it skills im afraid :wink: