Heltec Wifi LoRa32 V2 Join Accept fails

Hi there,

I’m trying to get a Heltec ESP32 LoRa V2 node running with TTN. So far it all looked promising but for some reason the board won’t process or receive a Join Accept and therefore can not establish a valid connection to TTN.

I’m trying to get the LMIC-node example to run (tried both the pure example and several modified versions) on the board and so far the board correctly starts up and sends a Join request to the gateway. From the TTN Console I can see that the request is received and that a Join Accept response gets issued. From the gateway logs I would think that the gateway receives the accept correctly.

I use the latest LMIC MCCI library.

Having a look at the serial console it seems the board is sending the Join message but it does not receive the Accept message and therefore gets stuck in a loop re-sending the Join request to the gateway. Interestingly it seems not all of the Join request messages appear in the TTN console.

I’m connected to a TTN Outdoor Gateway.

Here are the infos:

Gateway log in console:
ttn_gw

Device Log in console:
ttn_device

Gateway Log:


##### END #####

# GPS coordinates: latitude 49.97971, longitude 7.92296, altitude 92 m

# Valid time reference (age: 1 sec)

### [GPS] ###

# SX1301 time (PPS): 3854267887

### [JIT] ###

# BEACON rejected: 0

# BEACON sent so far: 4861

# BEACON queued: 4864

# TX rejected (too early): 0.00% (req:191, rej:0)

# TX rejected (too late): 0.00% (req:191, rej:0)

# TX rejected (collision beacon): 2.09% (req:191, rej:4)

# TX rejected (collision packet): 0.00% (req:191, rej:0)

# TX errors: 0

# RF packets sent to concentrator: 0 (0 bytes)

# PULL_RESP(onse) datagrams received: 0 (0 bytes)

# PULL_DATA sent: 3 (100.00% acknowledged)

### [DOWNSTREAM] ###

# PUSH_DATA acknowledged: 100.00%

# PUSH_DATA datagrams sent: 1 (154 bytes)

# RF packets forwarded: 0 (0 bytes)

# CRC_OK: 0.00%, CRC_FAIL: 100.00%, NO_CRC: 0.00%

# RF packets received by concentrator: 1

### [UPSTREAM] ###

##### 2022-03-16 14:48:13 GMT #####





INFO: Enabling GPS mode for concentrator's counter.

INFO: host/sx1301 time offset=(1647438238s:742218µs) - drift=-548µs

INFO: Disabling GPS mode for concentrator's counter...



INFO: [down] PULL_ACK received in 41 ms

INFO: [down] PULL_ACK received in 33 ms

INFO: [down] PULL_ACK received in 33 ms

INFO: [up] PUSH_ACK received in 34 ms

JSON up: {"stat":{"time":"2022-03-16 14:47:43 GMT","lati":49.97969,"long":7.92295,"alti":92,"rxnb":1,"rxok":1,"rxfw":1,"ackr":100.0,"dwnb":1,"txnb":2}}



##### END #####

# GPS coordinates: latitude 49.97969, longitude 7.92295, altitude 92 m

# Valid time reference (age: 1 sec)

### [GPS] ###

# SX1301 time (PPS): 3824267890

### [JIT] ###

# BEACON rejected: 0

# BEACON sent so far: 4861

# BEACON queued: 4864

# TX rejected (too early): 0.00% (req:191, rej:0)

# TX rejected (too late): 0.00% (req:191, rej:0)

# TX rejected (collision beacon): 2.09% (req:191, rej:4)

# TX rejected (collision packet): 0.00% (req:191, rej:0)

# TX errors: 0

# RF packets sent to concentrator: 2 (33 bytes)

# PULL_RESP(onse) datagrams received: 1 (211 bytes)

# PULL_DATA sent: 3 (100.00% acknowledged)

### [DOWNSTREAM] ###

# PUSH_DATA acknowledged: 100.00%

# PUSH_DATA datagrams sent: 2 (453 bytes)

# RF packets forwarded: 1 (23 bytes)

# CRC_OK: 100.00%, CRC_FAIL: 0.00%, NO_CRC: 0.00%

# RF packets received by concentrator: 1

### [UPSTREAM] ###

##### 2022-03-16 14:47:43 GMT #####



INFO: [down] PULL_ACK received in 32 ms

INFO: tx_start_delay=1493 (1493.562500) - (1497, bw_delay=1.500000, notch_delay=1.937500)

JSON down: {"txpk":{"imme":false,"tmst":3815239836,"freq":868.1,"rfch":0,"powe":14,"modu":"LORA","datr":"SF10BW125","codr":"4/5","ipol":true,"size":33,"ncrc":true,"data":"IL7QydHq5Ck/G2fqiDLK4t6N0b5wtoqXcsyQ+t89kj1M"}}



INFO: [down] PULL_RESP received  - token[0:191] :)

INFO: [up] PUSH_ACK received in 35 ms

JSON up: {"rxpk":[{"tmst":3810239836,"time":"2022-03-16T14:47:28.971944Z","tmms":1331477248971,"chan":5,"rfch":1,"freq":868.100000,"stat":1,"modu":"LORA","datr":"SF10BW125","codr":"4/5","lsnr":-2.5,"lsnr_min":-4.5,"lsnr_max":-1.2,"rssi":-115,"size":23,"da
ta":"AGfeBNB+1bNwaN4E0H7Vs3A5cnSloVo="}]}



INFO: Received pkt from mote: D004DE67 (fcnt=46037)



   => 00 00 80 BC 5C 4F 5F A4 00 00 00 00 00 00 00 00 00 

INFO: Beacon queued (count_us=4193267892, freq_hz=869525000, size=17):

INFO: tx_start_delay=1493 (1493.562500) - (1497, bw_delay=1.500000, notch_delay=1.937500)

INFO: Beacon dequeued (count_us=3809267937)

INFO: [down] PULL_ACK received in 35 ms

INFO: [down] PULL_ACK received in 32 ms

INFO: [up] PUSH_ACK received in 34 ms

JSON up: {"stat":{"time":"2022-03-16 14:47:13 GMT","lati":49.97968,"long":7.92294,"alti":92,"rxnb":0,"rxok":0,"rxfw":0,"ackr":100.0,"dwnb":0,"txnb":0}}

Serial Log from node:

Running in debugging mode
39605:  Event: EV_JOINING
39630:  Event: EV_TXSTART
442929:  Event: EV_JOIN_TXCOMPLETE
475615:  Event: EV_TXSTART
857513:  Event: EV_JOIN_TXCOMPLETE

where the EV_TXSTART and EV_JOIN_TXCOMPLETE events will go on forever.

I believe this issue might be the same I have, unfortunately without a solution. I already tried the same things as the issue’s author.

Maybe anyone can help?

cheers

Let’s get this one out the way - devices do not connect to a gateway. Devices broadcast. Gateways listen. The two are not connected.

The settings would appear to be valid but your device is not hearing the join accept - looking at the signal information it would either be a long way from the gateway or it doesn’t have an actual antenna connected.

Hi Nick, sorry for using the wrong terms here. Sure the connection (or rather session I guess) gets established between a device and the TTN server.

Well I have an external antenna connected to the board, the connector is not loose. The gateway sits in the next room, the walls don’t have any special materials that would shield the signal significantly. It’s possible that either the board or the antenna might be damaged. I’ll check this tomorrow with a spare board and antenna.

Cheers Moritz

No worries!

I’d expect an RSSI around the -70 mark and a pretty positive SNR around 10

When you use the LIMI-node

Check the following setting -

End-Device- General Settings - Network layer - LoRaWAN version

This should be ‘LoRaWAN Specification 1.0.3’

Well it seems the unit was actually faulty. I replaced the board and it is working as expected. Thanks for the help, I really didn’t notice the bad signal…

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