Downlink message always the same (Digital Output)


Dear Cayenne users,

I’m using Cayenne to gather data coming from sensors on a STM32 P-Nucleo-LRWAN1 board. The communication protocol is LoRaWAN.
The data from the sensors (humidity, temperature …) is refreshed correctly on the Cayenne interface.

I have also a digital output, a light. When I switch ON–>OFF or when I switch OFF–>ON, the downlink message (in clear) is still the same: 0x15 0x00 0x20 0xD5
So I cannot detect if I have to switch on or off the light on my STM32 board

Are you facing to the same issue? Is it a bug ?

Thanks in advance for your feedback :slight_smile:


Which LoRaWAN provider are you using?


Actility (ThinkPark)


Am I alone to have this issue?


Hi @Aurelien,

Have you seen our downlink documentation?



Yes I have.
I send several uplink messages on which the digital output state is mentioned.
Uplink messages sent: 007326e3016700d2026864030064040100, my digitial ouptut channel is 4 and my led is switched off. The format seems correct.

After a several uplink message exchanged, I receive a downlink message (I switch the led on thanks to Cayenne interface):
(unciphered) Downlink message: 0x15 0x00 0x20 0xD5

At this point, the device should send another uplink message confirming the current state of the actuator.

I cannot reply a correct uplink message because the downlink message does not have a correct format and therefor no sense.

Do I have a wrong spec interpretation?


Tagging @croczey the LoRa master