xDot Not Receiving TTN Acknowledgements

[Matt Brown]

Hi,

I’ve just unpacked my new xDot developer kit and joined it to The Things Network using the AT command interface. That was pretty easy.

But, I’m not receiving acknowledgements for confirmed messages.

I can see the message in TTN and, AFAICT, TTN knows an ACK needs to be sent. The xDot opens and closes its receives windows without seeing the ACK or any downlink message.

I’m guessing that this is a timing issue but couldn’t find any configuration to play with on TTN or the xDot.

Hopefully it is just newbie finger trouble! 🙂

Thanks,
Matt

xDot AT command interface:

    at+send=matt
    OK
    at+ack=1
    OK
    at+send=matt
    ACK not received
    ERROR

Logging console:

    [DEBUG] Send with tx timeout 40000
    [INFO] Preparing frame
    [TRACE] NA:
    [TRACE] NSK:
    [TRACE] DSK:
    [TRACE] Adding MIC to frame
    [TRACE] Sending 17 bytes
    [TRACE] Number of available channels: 3
    [DEBUG] Using channel 1 : 868300000
    [INFO] Configure radio for TX
    [DEBUG] Session pwr: 20 ant: 3 max: 14
    [DEBUG] Radio Power index: 10 output: 11 total: 14
    [DEBUG] TX PWR: 10 DR: 0 SF: 12 BW: 0 CR: 1 PL: 8 CRC: 1 IQ: 0
    [INFO] Configure radio for TX
    [DEBUG] Session pwr: 20 ant: 3 max: 14
    [DEBUG] Radio Power index: 10 output: 11 total: 14
    [DEBUG] TX PWR: 10 DR: 0 SF: 12 BW: 0 CR: 1 PL: 8 CRC: 1 IQ: 0
    [DEBUG] update TOE: freq: 868300000 i:1 toa: 1318 DC:100
    [DEBUG] mDotEvent - TxDone
    [TRACE] Event: OK
    [TRACE] Flags Tx: 1 Rx: 0 RxData: 0 RxSlot: 0 LinkCheck: 0 JoinAccept: 0
    [TRACE] Info: Status: 0 ACK: 0 Retries: 0 TxDR: 0 RxPort: 0 RxSize: 0     RSSI: 0 SNR: 0 Energy: 0 Margin: 0 Gateways: 0
    [DEBUG] RadioEvent - TxDone
    [TRACE] RX1 on freq: 868300000
    [TRACE] RX DR: 0 SF: 12 BW: 0 CR: 1 PL: 8 STO: 8 CRC: 0 IQ: 1
    [TRACE] Stats: Up: 4 Down: 1 DupTx: 0 CRC Errors: 0
    [INFO] Rx Window 1
    [DEBUG] mDotEvent - MissedAck : retries 0
    [TRACE] Event: RX_TIMEOUT
    [TRACE] Flags Tx: 0 Rx: 0 RxData: 0 RxSlot: 1 LinkCheck: 0 JoinAccept: 0
    [TRACE] Info: Status: 3 ACK: 0 Retries: 0 TxDR: 0 RxPort: 0 RxSize: 0 RSSI: 0 SNR: 0 Energy: 0 Margin: 0 Gateways: 0
    [TRACE] RX2 on freq: 923300000
    [TRACE] RX DR: 3 SF: 9 BW: 0 CR: 1 PL: 8 STO: 12 CRC: 0 IQ: 1
    [TRACE] Stats: Up: 4 Down: 1 DupTx: 0 CRC Errors: 0
    [INFO] Rx Window 2
    [DEBUG] mDotEvent - MissedAck : retries 0
    [TRACE] Event: RX_TIMEOUT
    [TRACE] Flags Tx: 0 Rx: 0 RxData: 0 RxSlot: 2 LinkCheck: 0 JoinAccept: 0
    [TRACE] Info: Status: 3 ACK: 0 Retries: 0 TxDR: 0 RxPort: 0 RxSize: 0 RSSI: 0 SNR: 0 Energy: 0 Margin: 0 Gateways: 0
    [ERROR] ACK not received
    [DEBUG] ACK timeout repMax: 1 ackMax: 1

[Matt Brown]

It appears that joining the network isn’t as easy as I first thought.

I didn’t notice the first time but while messing around this morning I’ve discovered that at+join always fails on the first attempt after a reset and I always have to do at+join twice.

Matt

[Matt Brown]

FYI, I moved on to experimenting with the Dot-Examples and they worked.

So I don’t know if there is something wrong with the AT command interface or my fingers but I don’t care because I’m not planning on using the AT command interface for our product (it was just the first thing I tried with my new xDot).

[Author]

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