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Lora-net / LoRaMac-node

Reference implementation and documentation of a LoRa network node.
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LoRA can't transmit more than 64 byte #722

Closed pointone closed 5 years ago

pointone commented 5 years ago

I tried to make my project based on the example of ping-pong Lora mode and SX1278. If I send a packet more then 64 bytes, the receiver does not receive it. Smaller packages are accepted normally. BUFFER_SIZE in the main.c file has been increased accordingly. Can master branch implementation be used to send packets larger than 64 bytes (and smaller than 256 bytes)?

trick2011 commented 5 years ago

What SF (spreading factor)/DR (datarate) are you using? You won't be able to transmit more than 51 bytes by LoRaWAN specifications if you are using SF12 (at least in the EU area (868MHz)). There are even LoRaWAN networks which don't even allow bigger messages because a node is then unable to transmit its data when the connection is poor.

pointone commented 5 years ago

We operate at 434 MHz and use the following settings:

define TX_OUTPUT_POWER 20 // dBm

define LORA_BANDWIDTH 0 // 0: 125 kHz

define LORA_SPREADING_FACTOR 7 // SF7..SF12

define LORA_CODINGRATE 1 // 1: 4/5

define LORA_PREAMBLE_LENGTH 8 // Same for Tx and Rx

define LORA_FIX_LENGTH_PAYLOAD_ON false

define LORA_IQ_INVERSION_ON false

define TX_TIMEOUT_VALUE 3000

Radio.SetTxConfig( MODEM_LORA, TX_OUTPUT_POWER, 0, LORA_BANDWIDTH, LORA_SPREADING_FACTOR, LORA_CODINGRATE, LORA_PREAMBLE_LENGTH, LORA_FIX_LENGTH_PAYLOAD_ON, true, 0, 0, LORA_IQ_INVERSION_ON, TX_TIMEOUT_VALUE );

Radio.SetRxConfig( MODEM_LORA, LORA_BANDWIDTH, LORA_SPREADING_FACTOR, LORA_CODINGRATE, 0, LORA_PREAMBLE_LENGTH, LORA_SYMBOL_TIMEOUT, LORA_FIX_LENGTH_PAYLOAD_ON, 0, true, 0, 0, LORA_IQ_INVERSION_ON, true );

mirzafahad commented 5 years ago

@pointone The Ping-Pong example has this line:

#define BUFFER_SIZE 64 // Define the payload size here