?1.概述

本文主要基于LoRa調(diào)制功能的無(wú)線串口模塊的樹(shù)莓派擴(kuò)展板，講述在M4核LoRa的調(diào)試過(guò)程。

2.硬件資源

?Typec Debug線1根

?Micro usb線1根

?MYD-15XC-T開(kāi)發(fā)板

?樹(shù)莓派接口SX1262 868M LoRa HAT模塊2個(gè)

3.軟件資源

?Linux 5.4.31

?STM32CubeIDE 1.5.0

?LInux虛擬機(jī)

?米爾提供的SDK

4.環(huán)境準(zhǔn)備

預(yù)先安裝好CubeIDE等開(kāi)發(fā)軟件并搭建好Linux虛擬機(jī)環(huán)境，具體環(huán)境搭建請(qǐng)參考米爾的軟件開(kāi)發(fā)手冊(cè)《MYD-YA15XC-T_Linux軟件開(kāi)發(fā)指南》。

5.操作步驟

5.1.硬件介紹與設(shè)置

1)硬件介紹

關(guān)于樹(shù)莓派接口SX1262 868M LoRa HAT模塊的硬件介紹與設(shè)置請(qǐng)參考微雪官網(wǎng)：

https://www.waveshare.net/wiki/SX1262_868M_LoRa_HAT

2)接線與設(shè)置

需要兩個(gè)LoRa模塊，一個(gè)LoRa模塊通過(guò)Micro USB連接至PC，跳帽置于A，M1和M0連接GND，打開(kāi)SSCOM串口軟件連接LoRa模塊。另外一個(gè)LoRa模塊跳帽連接B，M0、M1跳帽移除改用MYD-YA15XC-T開(kāi)發(fā)板的GPIO使用，如下圖所示：

圖5-1. 連接與配置

5.2.CubeMX配置

設(shè)置時(shí)鐘為209M，如下圖只需要在紅色框輸入209M，按“Enter”，會(huì)自動(dòng)設(shè)置時(shí)鐘參數(shù)：

圖 5-1.時(shí)鐘設(shè)置

由于該模塊通訊接口使用的是串口，所以還需要設(shè)置usart外設(shè)，并使能中斷：

圖 5-2.串口設(shè)置

接著勾選串口中斷，通過(guò)中斷收發(fā)：

圖5-3.串口中斷

5.3.軟件設(shè)計(jì)

由5.2節(jié)生成代碼之后，在工程目錄新建“LoRa”目錄，用來(lái)存放LoRa的配置代碼(微雪官網(wǎng)有該模塊設(shè)置源碼，用戶可以直接移植)：

設(shè)置寄存器配置模式,這里首先需要設(shè)置模式2進(jìn)行寄存器配置：

void cfg_sx126x_io(uint8_t status)

{

if(CFG_REGISTER == status){

M0_RESET();

M1_SET();

HAL_Delay(5);

}else if(NORMAL_STATUS == status){

M0_RESET();

M1_RESET();

HAL_Delay(5);

}else if(WOR_STATUS == status){

M0_SET();

M1_RESET();

HAL_Delay(5);

}else if(SLEEP_STATUS == status){

M0_SET();

M1_SET();

HAL_Delay(5);

}

}

配置寄存器，設(shè)置波特率9600，廣播監(jiān)聽(tīng)地址：

/******************************************************************************

sx126x mode :broadcast & monitor mode

parameter:

address_high:0xff

address_low:0xff

net_id: 0x00

serial:0x62

power: 0x00

channel: 0x12

transmission_mode: 0x03

crypt_high: 0x00

crypt_low: 0x00

******************************************************************************/

lora_para_t transparent_mode = {

.address_high = BROADCAST_ADDH_VALUE,

.address_low = BROADCAST_ADDL_VALUE,

.net_id = BROADCAST_NETID_VALUE,

.serial = BROADCAST_SERIAL_VALUE,

.power = BROADCAST_POWER_VALUE,

.channel = BROADCAST_CHANNEL_VALUE,

.transmission_mode = BROADCAST_TRANSIMISSION_VALUE,

.crypt_high = BROADCAST_CRYPTH_VALUE,

.crypt_low = BROADCAST_CRYPTL_VALUE

};

設(shè)置寄存器：

uint8_t sx126x_write_register(lora_para_t para)

{

int8_t i;

buffer[0] = CFG_HEADER;

buffer[1] = REG_START;

buffer[2] = REG_NUMBER;

for(i=3;i<12;i++){

buffer[i] = *(?.address_high + i - 3);

}

HAL_UART_Transmit_IT(&huart3,(uint8_t *)buffer,12);

HAL_UART_Receive_IT(&huart3,(uint8_t *)buffer,12);

HAL_Delay(500);

if(CFG_RETURN == buffer[0]){

buffer[0] = 0;

init_cplt_flag = SUCCESS;

return SUCCESS;

}

return ERROR;

}

定義發(fā)送的信息：

/* USER CODE BEGIN 1 */

uint8_t transparent_string[] = "Helloworld";//"This is a transparent message\r\n";

uint32_t delay;

/* USER CODE END 1 */

主函數(shù)里，使用串口中斷進(jìn)行發(fā)送和接收處理：

/* Infinite loop */

/* USER CODE BEGIN WHILE */

while (1)

{

/* USER CODE END WHILE */

/* USER CODE BEGIN 3 */

if(delay++>18000000){

HAL_UART_Transmit_IT(&huart3,transparent_string,strlen((const char *)transparent_string));

delay = 0;

}

if(SUCCESS == over_flag){

HAL_UART_Transmit_IT(&huart3,buffer,strlen((const char *)buffer));

over_flag = ERROR;

rece_count = 0;

HAL_UART_Receive_IT(&huart3,(uint8_t *)&rece_buff,1);

}

}

5.4.測(cè)試

1)量產(chǎn)模式啟動(dòng)m4固件

啟動(dòng)開(kāi)發(fā)板，并啟動(dòng)m4固件，如下：

root@myir-ya151c-t-4e512d:~# cp LoRa_CM4.elf /lib/firmware/

root@myir-ya151c-t-4e512d:~# echo LoRa_CM4.elf > /sys/class/remoteproc/remotepro

c0/firmware

root@myir-ya151c-t-4e512d:~# echo start > /sys/class/remoteproc/remoteproc0/stat

e

[ 82.845983] remoteproc remoteproc0: powering up m4

[ 82.859219] remoteproc remoteproc0: Booting fw image LoRa_CM4.elf, size 2532532

[ 82.865319] remoteproc remoteproc0: header-less resource table

[ 82.870883] remoteproc remoteproc0: no resource table found for this firmware

[ 82.884297] remoteproc remoteproc0: header-less resource table

[ 82.888689] remoteproc remoteproc0: remote processor m4 is now up

2)信息接收

打開(kāi)sscom，可以看到usb控制的LoRa模塊能接收到數(shù)據(jù)，如下圖所示：

圖 5-2.數(shù)據(jù)接收