Question to E78-868LN22S LoRaWAN Module (ASR6501 Chip) - Payload 0 bytes?


at the moment I am testing the E78-868LN22S LoRaWAN module
(ASR6501 chip)

the module is connected to the TTN,
device information on the TTN Console: registered device

if i send a payload 0123456789 (AT+DTRX=1,2,10,0123456789),
then i do not see the payload on the TTN Console (0 bytes)

what could be the reason ?

thank you.

my test setup:

Does this mean you see an uplink entry - can you provide a screen shot as that’s the focus of attention.

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Did you set the all the parameters, did you perform a join prior to sending a ‘payload’ remember the payload is hexadecimal, so to transmit one byte your payload consists of two bytes …

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True from a human point of view. So, if the 10 in AT+DTRX=1,2,10,0123456789 is the length, then that should read 5 for 0123456789. (I don’t know that device/its commands.)

And if you have access to the gateway’s log or its Traffic page in TTN Console, then copying the complete LoRaWAN packet here will help too.

i did not change the module settings,
but now, sometimes i see the payload,

the dev addr is changing and i see a lot of activation entries ?


Looks like it’s resetting or having power problems.

What is the power supply and what is sending commands to the module?

power supply is usb -> ldo -> module,
up to 500mA, i can measure with osci.

now i switched for test to ABP:

and what is sending commands to the module?

i used following commands:













i will measure the power supply and
i should add 2 caps 100u + 100n to VCC.

Is this through a serial port as what I was trying to find out was what sort of microcontroller you were using to drive the E78 module - like STM32 or MSP430 or ATmega4809?

I just ordered two of these to play with, it will take some time before they arrive.

i connected the module serial port (3.3v uart)
via the cp2102 (usb uart bridge) to my win10 device.

i am already using E32 LoRa modules from ebyte,
they are working fine,

my test:

now i like to start with LoRaWAN.

Your commands appear to turn off confirm but the screen shot for ABP looks like it’s confirming so it’s not clear what the settings may be.

Can you try a CSTATUS after the DTRX to see what the result was?

I see you are using a prototyping board to evaluate your E78 module.

You may think about to transit onto my E78 breakout board design:

i measured the supply voltage close to the module,
there was a voltage drop about 300mV during initialisation and
a voltage drop about 300mV during Tx.

(3.3V-0.3V is still inside the specification 2.5V-3.7V,
but maybe this can cause some instability)

i added 1000uF and a connection for optional external power supply,
now the supply voltage is clean and stable.

07 – there is data sent and success but no download

the breakout board looks fine,
have you calculated the rf-output-trace to 50R ?

now sending data to TTN is working fine,
i use AT+DTRX=0,1,10,0123456789
(without ack.)

maybe there is a space (wiki) on TTN available
for creating a small docu - connecting E78… to TTN.