Lilygo/Heltec RTL 433 issues

1

I recently bought a ESP32 LORA board on ebay advertised as a TTGO LORA 433MHz device.
It displayed a TTGO splash screen on the OLED when I powered on.

I used the ‘upload from web’ facility for TTGO & the display went blank. The messages in the serial console looked wrong too.

The board I have is unmarked. It’s presumably a clone as it looks slightly different to any TTGO device I can find on the web.

Out of curiosity I uploaded the Heltec RTL_433 code & it came to life (almost). The OLED works, WiFi & MQTT connect, the serial console seems sensible!

BUT I’ve tried several 433MHz devices (which worked in older versions of OMG) and nothing is recognised :frowning:

I’m wondering if my board is not 433MHz? Do you know how I might check this?

On a similar note: could you produce a ‘generic’ ESP32/LORA schematic? I have many ESP32 boards & SSD1306 I2C OLEDs. The TTGO & Heltec boards are quite expensive when all I really need is a 1276/8 LORA module.

Cheers
Ian

2

I’m wondering if my board is not 433MHz? Do you know how I might check this?

For it to work at 433 Mhz, it would need the sx1278 chipset, and a proper RF antennae, you should be able to determine by looking at the chips on the board.

On a similar note: could you produce a ‘generic’ ESP32/LORA schematic? I have many ESP32 boards & SSD1306 I2C OLEDs. The TTGO & Heltec boards are quite expensive when all I really need is a 1276/8 LORA module.

For a generic layout etc, what about just looking at the pinouts for the lilygo board, they are pretty detailed.

3

Without destroying my board I can’t identify the chip. It’s under the OLED which seems firmly attached.

I’m not sure what the debug messages mean in the serial dialogue. Are these posts to my MQTT server/broker? They’re not received by my server.

Does this look sensible?

************* WELCOME TO OpenMQTTGateway **************
N: SSD1306 config initialised
[ 137][E][Preferences.cpp:483] getString(): nvs_get_str len fail: SSD1306Config NOT_FOUND
N: No SSD1306 config to load
N: Setup SSD1306 Display end
N: OpenMQTTGateway Version: v1.5.1
{
“mqtt_server”: “192.168.68.68”,
“mqtt_port”: “1883”,
“mqtt_user”: “your_username”,
“mqtt_pass”: “your_password”,
“mqtt_topic”: “home/”,
“gateway_name”: “OpenMQTTGateway_heltec_rtl_433_ESP”,
“mqtt_broker_secure”: false,
“mqtt_broker_cert”: “”,
“mqtt_ss_index”: 0,
“ota_server_cert”: “”,
“ota_pass”: “OTAPASSWORD”
}*wm:[2] Added Parameter: server
*wm:[2] Added Parameter: port
*wm:[2] Added Parameter: user
*wm:[2] Added Parameter: pass
*wm:[2] Added Parameter: secure
*wm:[2] Added Parameter: cert
*wm:[2] Added Parameter: name
*wm:[2] Added Parameter: topic
*wm:[2] Added Parameter: ota
N: Attempting Wifi connection with saved AP: 0
N: Attempting Wifi connection with saved AP: 1
E (5142) wifi:sta is connecting, return error
[ 2393][E][WiFiSTA.cpp:317] begin(): connect failed! 0x3007
N: Attempting Wifi connection with saved AP: 2
E (6152) wifi:sta is connecting, return error
[ 3402][E][WiFiSTA.cpp:317] begin(): connect failed! 0x3007
N: Attempting Wifi connection with saved AP: 3
E (7160) wifi:sta is connecting, return error
[ 4410][E][WiFiSTA.cpp:317] begin(): connect failed! 0x3007
N: ZgatewayRTL_433 setup done
N: Switching to RTL_433 Receiver: 433.92Mhz
N: OpenMQTTGateway modules: [“HELTEC_SSD1306”,“rtl_433”]
N: ************** Setup OpenMQTTGateway end **************
W: MQTT connection…
N: Connected to broker
N: Send on /SYStoMQTT msg {“uptime”:14,“version”:“v1.5.1”,“discovery”:true,“env”:“heltec-rtl_433”,“freemem”:128908,“mqttport”:“1883”,“mqttsecure”:false,“tempc”:53.33333,“freestack”:4716,“rssi”:-59,“SSID”:“Dlink4G”,“BSSID”:“1E:21:B4:CF:54:6E”,“ip”:“192.168.68.70”,“mac”:“80:7D:3A:D4:54:F0”,“actRec”:3,“mhz”:433.92,“RTLRssiThresh”:-82,“RTLRssi”:-94,“RTLAVGRssi”:0,“RTLCnt”:0,“RTLOOKThresh”:15,“modules”:[“HELTEC_SSD1306”,“rtl_433”]}
N: Send on /SSD1306toMQTT msg {“onstate”:true,“brightness”:50,“displaymetric”:true,“display-flip”:true,“idlelogo”:true,“log-oled”:false,“json-oled”:true}
N: Update checkN: Send on /RLStoMQTT msg {“latest_version”:“v1.5.1”,“title”:“OpenMQTTGateway”,“release_url”:“https://github.com/1technophile/OpenMQTTGateway/releases/tag/v1.5.1",“installed_version”:“v1.5.1”,“entity_picture”:“https://github.com/1technophile/OpenMQTTGateway/raw/development/docs/img/Openmqttgateway_logo_mini_margins.png”,“release_summary”:"”}
rtl_433_ESP(7): Average RSSI Signal -110 dbm, adjusted RSSI Threshold -101, samples 50000
rtl_433_ESP(7): Average RSSI Signal -110 dbm, adjusted RSSI Threshold -101, samples 50000
N: Send on /SYStoMQTT msg {“uptime”:134,“version”:“v1.5.1”,“discovery”:true,“env”:“heltec-rtl_433”,“freemem”:131948,“mqttport”:“1883”,“mqttsecure”:false,“tempc”:52.77778,“freestack”:1724,“rssi”:-59,“SSID”:“Dlink4G”,“BSSID”:“1E:21:B4:CF:54:6E”,“ip”:“192.168.68.70”,“mac”:“80:7D:3A:D4:54:F0”,“actRec”:3,“mhz”:433.92,“RTLRssiThresh”:-101,“RTLRssi”:-101,“RTLAVGRssi”:-110,“RTLCnt”:0,“RTLOOKThresh”:15,“modules”:[“HELTEC_SSD1306”,“rtl_433”]}
N: Send on /SSD1306toMQTT msg {“onstate”:true,“brightness”:50,“displaymetric”:true,“display-flip”:true,“idlelogo”:true,“log-oled”:false,“json-oled”:true}
rtl_433_ESP(7): Average RSSI Signal -110 dbm, adjusted RSSI Threshold -101, samples 50000
rtl_433_ESP(7): Average RSSI Signal -110 dbm, adjusted RSSI Threshold -101, samples 50000
N: Send on /SYStoMQTT msg {“uptime”:254,“version”:“v1.5.1”,“discovery”:true,“env”:“heltec-rtl_433”,“freemem”:132396,“mqttport”:“1883”,“mqttsecure”:false,“tempc”:53.33333,“freestack”:1724,“rssi”:-59,“SSID”:“Dlink4G”,“BSSID”:“1E:21:B4:CF:54:6E”,“ip”:“192.168.68.70”,“mac”:“80:7D:3A:D4:54:F0”,“actRec”:3,“mhz”:433.92,“RTLRssiThresh”:-101,“RTLRssi”:-98,“RTLAVGRssi”:-110,“RTLCnt”:0,“RTLOOKThresh”:15,“modules”:[“HELTEC_SSD1306”,“rtl_433”]}
N: Send on /SSD1306toMQTT msg {“onstate”:true,“brightness”:50,“displaymetric”:true,“display-flip”:true,“idlelogo”:true,“log-oled”:false,“json-oled”:true}
rtl_433_ESP(7): Average RSSI Signal -110 dbm, adjusted RSSI Threshold -101, samples 50000
rtl_433_ESP(7): Average RSSI Signal -110 dbm, adjusted RSSI Threshold -101, samples 50000
rtl_433_ESP(7): Average RSSI Signal -110 dbm, adjusted RSSI Threshold -101, samples 50000

4

A couple of comments

1 - The current development branch contains tuning to improve reception, you may want to switch to that

2 - OMG is seeing the transceiver, and the receiver is running

3 - This is automated signal background noise detector logic running

Average RSSI Signal -110 dbm, adjusted RSSI Threshold -101, samples 50000

Which samples the background noise and adjusts the signal detection logic to determine when a signal is present. What it is saying is that average RSSI noise level is -110

As a FYI - this is from my device, average RSSI noise level is -104

{“uptime”:853,“version”:“Office-LilyGo-v1.5.0-34-g9d3257ae[localDev]”,“discovery”:true,“env”:“Office-LilyGo”,“freemem”:130732,“mqttport”:“1883”,“mqttsecure”:false,“tempc”:47.22222,“freestack”:1724,“rssi”:-39,“SSID”:“xxxxx”,“BSSID”:“64:A5:C3:6F:1C:42”,“ip”:“192.168.1.249”,“mac”:“4C:75:25:A7:74:D4”,“actRec”:3,“mhz”:433.92,“RTLRssiThresh”:-95,“RTLRssi”:-102,“RTLAVGRssi”:-104,“RTLCnt”:2392,“RTLOOKThresh”:15,“modules”:[“LILYGO_OLED”,“BME280”,“rtl_433”]}

5

@NorthernMan54
Thanks for your reply. So it looks as if it’s working?
I’ll take a look at your suggestions when I have a moment.
I don’t have many 433MHz devices but they all work perfectly with a very old (RCSwitch) OMG. See:
http://myiot.co.uk/doorbell/
None of these work with RTL 433 :frowning:
Cheers
Ian