Downlinks from TTN in BL072Z with SF12 and LoPy4 not working?

End Devices (Nodes) Pycom
1

Hi, i am making some tests with my BL072Z board, with SF7 uplinks and downlinks are ok, but when i run the code with SF12 i only can send uplinks, in TTN i can see the scheduled downlink and in the next uplink the downlink is sent but in the BL072Z board i don’t receive anything, mi configs are:

#define OVER_THE_AIR_ACTIVATION                     0
#define LORAWAN_DUTYCYCLE_ON                        false
#define APP_TX_DUTYCYCLE                            10000
#define LORAWAN_ADR_STATE LORAWAN_ADR_OFF
#define LORAWAN_DEFAULT_DATA_RATE DR_0
#define EU868_DEFAULT_DATARATE                      DR_0

the default frequencies were 868100000, 868300000, 868500000 but i am using a single channel gateway working in 868100000 that is why i changed the config, if i keep the default values some uplinks are lost

/*!
 * LoRaMac default channel 1
 * Channel = { Frequency [Hz], RX1 Frequency [Hz], { ( ( DrMax << 4 ) | DrMin ) }, Band }
 */
#define EU868_LC1                                   { 868100000, 0, { ( ( DR_5 << 4 ) | DR_0 ) }, 1 }
 
//LoRaMac default channel 2
#define EU868_LC2                                   { 868100000, 0, { ( ( DR_5 << 4 ) | DR_0 ) }, 1 }
 
// LoRaMac default channel 3
#define EU868_LC3                                   { 868100000, 0, { ( ( DR_5 << 4 ) | DR_0 ) }, 1 }

the single channel gateway also is configured with SF12

Important:
when i turn on the adaptative data rate i can receive downlinks, but with every uplink TTN sends me an empty downlink, why?

thanks.

2

Most likely it is not empty, but rather contains MAC commands to adjust the data rate (ie, what ADR does) but with the application payload portion being empty.

3

Check frequency and SF used for downlinks by the gateway. TTN uses non standard settings on RX2 (https://www.thethingsnetwork.org/docs/lorawan/frequency-plans.html#eu863-870 )