64 byte limit of Payload

Issue: Hello, I am using a RAK811 shield with my Arduino.

According to LoRaWAN™ 1.0.2 Regional Parameters page 41, and based on the answers here, I should be able to send my data 133 - 8 = 125 bytes at DR4 with UplinkDwellTime = 1 (8 bytes is used for FOpts and verification).

However, I am only able to at most 64 bytes in this configuration.

May I know if there is any way to send a payload of larger than 64 bytes in DR4?

Setup: PiSupply LoRa Node shield (RAK811) AS923

Server: Chirpstack

Also, if I am not able to exceed 64 bytes anyways, is there any way for me to turn UplinkDwellTime to 0 on my Arduino shield? If there’s a way, how am I supposed to do that?

you need refer lora status,and confirm Dr = 4(at+get_config=lora:status).It could be more than 64 bytes at Dr =4.

If I am not mistaken, even though DR=4 can be more than 64 bytes the payload length is limited by the check in at_cmd.c

More specifically, line 730 of the code:

static void lora_send(int argc, char *argv[])

    uint8_t *app_data = (uint8_t *)argv[3];


    app_len = strlen(app_data);

    if (app_len > 128) {

    if (app_len%2) {


    ret = rw_LoRaTxData(confirm, app_port, app_len, app_data);


The check prevents the code from proceeding to rw_LoRaTxData (line 752 in at_cmd.c) which actually goes on to check regional parameters.

Could this be the reason that even at DR=4 the payload cannot be more than 64 bytes?

Yes, you are right, there is a byte footprint .:fist_right: :fist_right: :fist_right:

I would like to provide more information regarding this issue.

When I was trying to send 65 bytes at DR4 via AT-command, I received feedback of ERROR-1 at the serial monitor.

So… does that mean there’s no way to send anything that is larger than 64 bytes?

Could you tell me the version number you are using?
AT command:at+version

I am using, it’s an Arduino RAK811 shield by PiSupply.

Your version is too early. It is recommended that you upgrade the firmware to fix the problem.

May I know which firmware version will fix this? How am I supposed to update the firmware?

Thank you.

Can you send your email to me? I will send you the operation steps.

How can I give you my email privately? Can you give me an address for me to email you instead?

[email protected]