Overview:

This instruction is for how to use Peer to Peer firmware in LA66.

Firmware Location:

Click here to download the firmware and update it to LA66 according to the instruction for different boards.

How to use?

1. AT command：

1) Lora parameter configuration:

AT+FRE: Get or Set TX and RX frequency

AT+BW: Get or Set TX and RX BandWidth

AT+SF: Get or Set TX and RX Spreading Factor

AT+POWER: Get or Set Tx Power Range

AT+CRC: Get or Set TX and RX CRC Type

AT+HEADER: Get or Set TX and RX Header Type

AT+CR: Get or Set TX and RX Header Type

AT+IQ: Get or Set TX and RX InvertIQ

AT+PREAMBLE: Get or Set TX and RX Preamble Length

AT+SYNCWORD: Get or Set sync word

2) General configuration:

ATZ: Trig a reset of the MCU

AT+FDR: Reset Parameters to Factory Default

AT+CFG: Print all configurations

AT+FCU: Get or Set the Frame Counter Uplink

AT+FCD: Get or Set the Frame Counter Downlink

AT+GROUPMOD: Get or Set TX and RX group

AT+RXMOD: Get or Set Rx Timeout and Reply mode

AT+SEND: Send text data or hex along with the application port and confirm status

AT+RECV: Print last receive message, RSSI and SNR

2. Serial port information

1) Information initialized at reset：

2) In retransmission, the Uplinkcounter does not accumulate. The following figure shows that the third count packet is retransmitted twice when the ACK packet is not received.

3) In the figure below, the receiver sends an ACK to the sender after receiving the packet, and the sender stops retransmission after receiving the ACK.

Receiver: (configured as AT+RXMOD=65535,2)

Sender:

3. Data Format:

1 byte of TXGROUPMOD +n payload + 4 bytes of checksum

Payload(S12, SF11, SF10 maximum length is 59, SF9 maximum length is 123, SF8, SF7 maximum length is 230):

AT Command Set.

Set TX and RX Bandwidth

Set TX and RX BandWidth (0 ~ 9)
0: 125 kHz
1: 250 kHz
2: 500 kHz
3: 62.5 kHz
4: 41.67 kHz
5: 31.25 kHz
6: 20.83 kHz
7: 15.63 kHz
8: 10.42 kHz
9: 7.81 kHz

Default Value: AT+BW=0,0   // BandWidth: 125kHz ,125kHz

Range: (0 ~ 9)