SPMOD - LoRa

Overview

SPMOD_LoRa(LoRa Module) uses M-XL8 module.

SPMOD - LoRa Introduction

• Using Sipeed-SPMOD interface(2.54mm * 8PIN )，unified MaixPy board interface
• Using SP-MOD SPI to communicate with LoRa module
• LoRa module:The SP_LoRa module uses M-XL8 module with LoRaTM modem and LoRa module with adjustable power amplifier. It has high performance and reliability and is connected by SP_MOD.
• 370MHz-1200MHz, Maximum 20dBm (100mW) continuous transmit power
• Size:25.0*10.0*4.3mm

M-XL8 SX1276 LoRa module Introduction

Built-in LoRaTM modem, built-in CRC, inherited +12dBm adjustable PA+LNA

SPMOD_lora pin description:

• Mode of communication

Usage

• Process

  1. Create the LoRa object and initialize it
  2. Send or receive data

C :

fpioa_set_function(SPI_LoRa_SX127X_CS_PIN_NUM, FUNC_SPI1_SS0);   // CS: 20
fpioa_set_function(SPI_LoRa_SX127X_SCK_PIN_NUM, FUNC_SPI1_SCLK); // SCLK: 21
fpioa_set_function(SPI_LoRa_SX127X_MOSI_PIN_NUM, FUNC_SPI1_D0);  // MOSI: 8
fpioa_set_function(SPI_LoRa_SX127X_MISO_PIN_NUM, FUNC_SPI1_D1);  // MISO: 15

fpioa_set_function(SPI_LoRa_SX127X_IRQ_PIN_NUM, FUNC_GPIOHS0 + SPI_LoRa_SX127X_IQR_GPIO_NUM); // IQR: 6
fpioa_set_function(SPI_LoRa_SX127X_RST_PIN_NUM, FUNC_GPIOHS0 + SPI_LoRa_SX127X_RST_GPIO_NUM); // RST: 7

spi_init(SPI_DEVICE_1, SPI_WORK_MODE_0, SPI_FF_STANDARD, DATALENGTH, 0);

sx1278_begin(&SX1278, SX1278_433MHZ, SX1278_POWER_17DBM, SX1278_LoRa_SF_8,
               SX1278_LoRa_BW_20_8KHZ, 10);

if (master == 1)
{
    printf("====MASTER====\r\n");
    ret = sx1278_LoRaEntryTx(&SX1278, 16, 2000);
}
else
{
    printf("====SALAVE====\r\n");
    ret = sx1278_LoRaEntryRx(&SX1278, 16, 2000);
}

MaixPy :

fm.register(20, fm.fpioa.GPIOHS20, force=True) # RST
fm.register(7, fm.fpioa.GPIOHS7, force=True) # CS

# set gpiohs work mode to output mode
cs = GPIO(GPIO.GPIOHS20, GPIO.OUT)
rst = GPIO(GPIO.GPIOHS7, GPIO.IN)
# The other pins are configured at SPI initialization time

spi1 = SPI(SPI.SPI1, mode=SPI.MODE_MASTER, baudrate=100 * 1000,
             polarity=0, phase=0, bits=8, firstbit=SPI.MSB, sck=21, mosi=8, miso = 15)

lora = SX127x(spi=spi1, pin_ss=cs)
lora.init()

#######receiver###########
receive(lora)

########sender###########
# send(lora)

Runtime environments:

The MaixPy firmware is recommended to compile from the latest source

Result

• C

  

• MaixPy

  

Transplant

The following parameters need to be modified

• C

    // board_config.h
    #define SPI_INDEX           1
    #define SPI_SCLK_RATE       600*1000
    #define SPI_CHIP_SELECT_NSS 0//SPI_CHIP_SELECT_0
  
    #define SPI_LoRa_SX127X_CS_PIN_NUM      20
    #define SPI_LoRa_SX127X_SCK_PIN_NUM     21
    #define SPI_LoRa_SX127X_MOSI_PIN_NUM    8
    #define SPI_LoRa_SX127X_MISO_PIN_NUM    15
  
    #define SPI_LoRa_SX127X_IRQ_PIN_NUM     6
    #define SPI_LoRa_SX127X_RST_PIN_NUM     7
  
    #define SPI_LoRa_SX127X_IQR_GPIO_NUM    6
    #define SPI_LoRa_SX127X_RST_GPIO_NUM    7
  

• MaixPy

    ################### config ###################
    LoRa_RST = const(20)
    LoRa_CS = const(7)
    LoRa_SPI_SCK = const(21)
    LoRa_SPI_MOSI = const(8)
    LoRa_SPI_MISO = const(15)
    LoRa_SPI_NUM = SPI.SPI1
    LoRa_SPI_FREQ_KHZ = const(100)
    ##############################################
  

Outlook

• SPMOD_LoRa Size drawing:

Resource Link