Grove - LoRa-E5 P2P Example

This is the example of how to build a Point-to-Point Transmission Application with Grove - LoRa-E5 and Seeeduino XIAO.

Preparations

• Grove - Lora E5 * 2
• Seeeduino XIAO * 2
• Seeeduino XIAO Expansion board * 2
• USB typc cable * 2

If this is your first time using Seeeduino XIAO, please refer to Seeeduino XIAO's wiki.

If this is your first time using Arduino, Please put hand on here to start your Arduino journey.

Connecting hardware

We can connect the LoRa-E5 module to the UART socket directly as the below picture shows.

Download Library

The u8g2 library must be installed for this demo. Click to download the library and install it (How to install an Arduino Library).

Download the example

Copy the code stick on the Aruino IDE then upload it. One of them is used as a master, and the NODE_SLAVE macro definition in the code needs to be commented out, and the other is used as a slave, and the NODE_SLAVE macro definition in the code needs to be turned on.

#include <Arduino.h>
#include <U8x8lib.h>
 
// #define NODE_SLAVE
 
U8X8_SSD1306_128X64_NONAME_HW_I2C u8x8(/* reset=*/U8X8_PIN_NONE);
// U8X8_SSD1306_128X64_NONAME_SW_I2C u8x8(/* clock=*/ SCL, /* data=*/ SDA, /* reset=*/ U8X8_PIN_NONE);   // OLEDs without Reset of the Display
 
static char recv_buf[512];
static bool is_exist = false;
 
static int at_send_check_response(char *p_ack, int timeout_ms, char *p_cmd, ...)
{
    int ch = 0;
    int index = 0;
    int startMillis = 0;
    va_list args;
    memset(recv_buf, 0, sizeof(recv_buf));
    va_start(args, p_cmd);
    Serial1.printf(p_cmd, args);
    Serial.printf(p_cmd, args);
    va_end(args);
    delay(200);
    startMillis = millis();
 
    if (p_ack == NULL)
    {
        return 0;
    }
 
    do
    {
        while (Serial1.available() > 0)
        {
            ch = Serial1.read();
            recv_buf[index++] = ch;
            Serial.print((char)ch);
            delay(2);
        }
 
        if (strstr(recv_buf, p_ack) != NULL)
        {
            return 1;
        }
 
    } while (millis() - startMillis < timeout_ms);
    return 0;
}
 
static int recv_prase(void)
{
    char ch;
    int index = 0;
    memset(recv_buf, 0, sizeof(recv_buf));
    while (Serial1.available() > 0)
    {
        ch = Serial1.read();
        recv_buf[index++] = ch;
        Serial.print((char)ch);
        delay(2);
    }
 
    if (index)
    {
        char *p_start = NULL;
        char data[32] = {
            0,
        };
        int rssi = 0;
        int snr = 0;
 
        p_start = strstr(recv_buf, "+TEST: RX \"5345454544");
        if (p_start)
        {
            p_start = strstr(recv_buf, "5345454544");
            if (p_start && (1 == sscanf(p_start, "5345454544%s", data)))
            {
                data[4] = 0;
                u8x8.setCursor(0, 4);
                u8x8.print("               ");
                u8x8.setCursor(2, 4);
                u8x8.print("RX: 0x");
                u8x8.print(data);
                Serial.print(data);
                Serial.print("\r\n");
            }
 
            p_start = strstr(recv_buf, "RSSI:");
            if (p_start && (1 == sscanf(p_start, "RSSI:%d,", &rssi)))
            {
                u8x8.setCursor(0, 6);
                u8x8.print("                ");
                u8x8.setCursor(2, 6);
                u8x8.print("rssi:");
                u8x8.print(rssi);
            }
            p_start = strstr(recv_buf, "SNR:");
            if (p_start && (1 == sscanf(p_start, "SNR:%d", &snr)))
            {
                u8x8.setCursor(0, 7);
                u8x8.print("                ");
                u8x8.setCursor(2, 7);
                u8x8.print("snr :");
                u8x8.print(snr);
            }
            return 1;
        }
    }
    return 0;
}
 
static int node_recv(uint32_t timeout_ms)
{
    at_send_check_response("+TEST: RXLRPKT", 1000, "AT+TEST=RXLRPKT\r\n");
    int startMillis = millis();
    do
    {
        if (recv_prase())
        {
            return 1;
        }
    } while (millis() - startMillis < timeout_ms);
    return 0;
}
 
static int node_send(void)
{
    static uint16_t count = 0;
    int ret = 0;
    char data[32];
    char cmd[128];
 
    memset(data, 0, sizeof(data));
    sprintf(data, "%04X", count);
    sprintf(cmd, "AT+TEST=TXLRPKT,\"5345454544%s\"\r\n", data);
 
    u8x8.setCursor(0, 3);
    u8x8.print("                ");
    u8x8.setCursor(2, 3);
    u8x8.print("TX: 0x");
    u8x8.print(data);
 
    ret = at_send_check_response("TX DONE", 2000, cmd);
    if (ret == 1)
    {
 
        count++;
        Serial.print("Sent successfully!\r\n");
    }
    else
    {
        Serial.print("Send failed!\r\n");
    }
    return ret;
}
 
static void node_recv_then_send(uint32_t timeout)
{
    int ret = 0;
    ret = node_recv(timeout);
    delay(100);
    if (!ret)
    {
        Serial.print("\r\n");
        return;
    }
    node_send();
    Serial.print("\r\n");
}
 
static void node_send_then_recv(uint32_t timeout)
{
    int ret = 0;
    ret = node_send();
    if (!ret)
    {
        Serial.print("\r\n");
        return;
    }
    if (!node_recv(timeout))
    {
        Serial.print("recv timeout!\r\n");
    }
    Serial.print("\r\n");
}
 
void setup(void)
{
 
    u8x8.begin();
    u8x8.setFlipMode(1);
    u8x8.setFont(u8x8_font_chroma48medium8_r);
 
    Serial.begin(115200);
    // while (!Serial);
 
    Serial1.begin(9600);
    Serial.print("ping pong communication!\r\n");
    u8x8.setCursor(0, 0);
 
    if (at_send_check_response("+AT: OK", 100, "AT\r\n"))
    {
        is_exist = true;
        at_send_check_response("+MODE: TEST", 1000, "AT+MODE=TEST\r\n");
        at_send_check_response("+TEST: RFCFG", 1000, "AT+TEST=RFCFG,866,SF12,125,12,15,14,ON,OFF,OFF\r\n");
        delay(200);
#ifdef NODE_SLAVE
        u8x8.setCursor(5, 0);
        u8x8.print("slave");
#else
        u8x8.setCursor(5, 0);
        u8x8.print("master");
#endif
    }
    else
    {
        is_exist = false;
        Serial.print("No E5 module found.\r\n");
        u8x8.setCursor(0, 1);
        u8x8.print("unfound E5 !");
    }
}
 
void loop(void)
{
    if (is_exist)
    {
#ifdef NODE_SLAVE
        node_recv_then_send(2000);
#else
        node_send_then_recv(2000);
        delay(3000);
#endif
    }
}

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