1. LoRa PHY

1. LoRa PHY

Description

Examples in this section demonstrate a simple device-to-device communication over LoRa PHY.

lora_phy_sender_example

The lora_phy_sender_example send a LoRa PHY packet every TX_INTERVAL seconds. Default configuration is given below.

lora_phy_receiver_example

The lora_phy_receiver_example listen continuously for LoRa PHY packets and print packet's information to serial monitor. Default configuration is given below.

lora_phy_doppler_simulate_tx_example (Sender)

lora_phy_doppler_simulate_rx_example (Receiver)

These sketches demonstrate the LoRa transmissions between a satellite and a ground station with doppler effect.

The Doppler effect or Doppler shift (or simply Doppler) is the change in frequency of a wave in relation to an observer who is moving relative to the wave source.

Every satellite in the constellations, as a high-speed carrier, causes inevitably the Doppler-effect to signals.

The lora_phy_doppler_simulate_tx_example is continuously sending LoRa PHY packets with a sequential shift on the center frequency. The lora_phy_doppler_simulate_tx_example is receive & plot the packet information to the Serial Monitor. Both sketches have the Low Datarate Optimization (LDRO) enabled to reduce the doppler effect.

LoRa PHY parameters

The parameters of LoRa PHY can be modify via following functions:

sx126x.set_tx_power(14);
sx126x.set_frequency(868100000);
sx126x.set_spreading_factor(RFT_LORA_SPREADING_FACTOR_7);
sx126x.set_bandwidth(RFT_LORA_BANDWIDTH_125KHZ);
sx126x.set_coding_rate(RFT_LORA_CODING_RATE_4_5);
sx126x.set_syncword(RFT_LORA_SYNCWORD_PUBLIC);

Function Description

Set LoRa Transmit Power

void set_tx_power(int8_t tx_power);

(Not available/needed for receivers)

Parameter	Value	Description
tx_power	-9 (0xF7) to +22 (0x16)	The TX output power in dBm with the step of 1 dBm

Set LoRa Transmit Frequency

void set_frequency(uint32_t frequency);

Parameter	Description
frequency	The TX frequency in Hz

Set LoRa Transmit Spreading Factor

void set_spreading_factor(rft_lora_spreading_factor_t spreading_factor);

Parameter	Value	Description
spreading_factor	RFT_LORA_SPREADING_FACTOR_5	Spreading Factor 5
spreading_factor	RFT_LORA_SPREADING_FACTOR_6	Spreading Factor 6
spreading_factor	RFT_LORA_SPREADING_FACTOR_7	Spreading Factor 7
spreading_factor	RFT_LORA_SPREADING_FACTOR_8	Spreading Factor 8
spreading_factor	RFT_LORA_SPREADING_FACTOR_9	Spreading Factor 9
spreading_factor	RFT_LORA_SPREADING_FACTOR_10	Spreading Factor 10
spreading_factor	RFT_LORA_SPREADING_FACTOR_11	Spreading Factor 11
spreading_factor	RFT_LORA_SPREADING_FACTOR_12	Spreading Factor 12

Set LoRa Transmit Bandwidth

void set_bandwidth(rft_lora_bandwidth_t bandwidth);

Parameter	Value	Description
bandwidth	RFT_LORA_BANDWIDTH_10KHZ	Bandwidth 10.42 kHz
bandwidth	RFT_LORA_BANDWIDTH_15KHZ	Bandwidth 15.63 kHz
bandwidth	RFT_LORA_BANDWIDTH_20KHZ	Bandwidth 20.83 kHz
bandwidth	RFT_LORA_BANDWIDTH_31KHZ	Bandwidth 31.25 kHz
bandwidth	RFT_LORA_BANDWIDTH_41KHZ	Bandwidth 41.67 kHz
bandwidth	RFT_LORA_BANDWIDTH_62KHZ	Bandwidth 62.50 kHz
bandwidth	RFT_LORA_BANDWIDTH_125KHZ	Bandwidth 125 kHz
bandwidth	RFT_LORA_BANDWIDTH_250KHZ	Bandwidth 250 kHz
bandwidth	RFT_LORA_BANDWIDTH_500KHZ	Bandwidth 500 kHz

Set LoRa Transmit Coding Rate

void set_coding_rate(rft_lora_coding_rate_t coding_rate);

Parameter	Value	Description
coding_rate	RFT_LORA_CODING_RATE_4_5	Coding Rate 4/5
coding_rate	RFT_LORA_CODING_RATE_4_6	Coding Rate 4/6
coding_rate	RFT_LORA_CODING_RATE_4_7	Coding Rate 4/7
coding_rate	RFT_LORA_CODING_RATE_4_8	Coding Rate 4/8

Set LoRa Transmit Syncword

void set_syncword(rft_lora_syncword_t syncword);

Parameter	Value	Description
syncword	RFT_LORA_SYNCWORD_PRIVATE	Private Network Syncword (0x1424)
syncword	RFT_LORA_SYNCWORD_PUBLIC	Public Network Syncword (0x3444)

Maintained by Prof. F. Ferrero & mtnguyen