Good Evening Guys,
I am posting this here, in hopes of finding someone, who has mixed and matched their Grove LoRa modules.
I am working on a project where I’d like to send recorded sensor values using LoRa.
For this purpose, I am using a Seeed Studio Grove LoRa Radio as the transmitter. It uses a RFM98 as its base. To connect the LoRa radio, I have a grove basic shield. LoRa is connected at D6 and D7. As far as I can tell, the transmitter side is working well. I am sending a string.
For receiving the transmission, I am using a Heltec LoRa v3, it uses a SX1262 LoRa chip.
The data displayed on the OLED display and the Serial Monitor is a string of unrecognized characters.
TRANSMITTING SIDE CODE
#include <RH_RF95.h>
#ifdef __AVR__
#include <SoftwareSerial.h>
SoftwareSerial SSerial(6, 7); // RX, TX
#define COMSerial SSerial
#define ShowSerial Serial
RH_RF95<SoftwareSerial> rf95(COMSerial);
#endif
void setup() {
ShowSerial.begin(115200);
ShowSerial.println("RF95 client test.");
if (!rf95.init()) {
ShowSerial.println("init failed");
while (1);
}
// Defaults after init are 434.0MHz, 13dBm, Bw = 125 kHz, Cr = 4/5, Sf = 128chips/symbol, CRC on
// The default transmitter power is 13dBm, using PA_BOOST.
// If you are using RFM95/96/97/98 modules which uses the PA_BOOST transmitter pin, then
// you can set transmitter powers from 5 to 23 dBm:
//rf95.setTxPower(13, false);
rf95.setFrequency(433.0);
rf95.setTxPower(12);
uint8_t a=1;
}
void loop() {
ShowSerial.println("Sending to rf95_server");
// Send a message to rf95_server
char someString[15] = "battery: %i";
char test[30];
snprintf(test, 30, someString, a);
ShowSerial.println(test);
delay(10);
rf95.send((uint8_t *)test, 30);
delay(5000);
}
SERIAL MONITOR OUTPUT
01:06:13.906 -> Sending to rf95_server
01:06:13.906 -> battery: 1
01:06:18.966 -> Sending to rf95_server
01:06:18.966 -> battery: 2
01:06:23.966 -> Sending to rf95_server
01:06:24.001 -> battery: 3
01:06:29.004 -> Sending to rf95_server
01:06:29.037 -> battery: 4
01:12:31.823 -> RF95 client test.
01:12:31.861 -> Sending to rf95_server
01:12:31.861 -> battery: 0
01:12:36.894 -> Sending to rf95_server
01:12:36.894 -> battery: 1
01:12:41.944 -> Sending to rf95_server
01:12:41.944 -> battery: 2
01:12:46.947 -> Sending to rf95_server
01:12:46.985 -> battery: 3
RECEIVER SIDE CODE
// Turns the 'PRG' button into the power button, long press is off
#define HELTEC_POWER_BUTTON // must be before "#include <heltec_unofficial.h>"
#include <heltec_unofficial.h>
#define PAUSE 300
#define FREQUENCY 433.0
// #define FREQUENCY 905.2 // for US
#define BANDWIDTH 125.0
#define SPREADING_FACTOR 7
#define TRANSMIT_POWER 2
#define LORA_PREAMBLE_LENGTH 8
#define CODING_RATE 5
#define SYNC_WORD 0x12
String rxdata;
volatile bool rxFlag = false;
long counter = 0;
uint64_t last_tx = 0;
uint64_t tx_time;
uint64_t minimum_pause;
// Can't do Serial or display things here, takes too much time for the interrupt
void rx() {
rxFlag = true;
}
struct Data {
int seq;
float y;
} data;
void setup() {
heltec_setup();
both.println("Radio init");
RADIOLIB_OR_HALT(radio.begin());
// Set the callback function for received packets
radio.setDio1Action(rx);
// Set radio parameters
both.printf("Frequency: %.2f MHz\n", FREQUENCY);
RADIOLIB_OR_HALT(radio.setFrequency(FREQUENCY));
both.printf("Bandwidth: %.1f kHz\n", BANDWIDTH);
RADIOLIB_OR_HALT(radio.setBandwidth(BANDWIDTH));
both.printf("Spreading Factor: %i\n", SPREADING_FACTOR);
RADIOLIB_OR_HALT(radio.setSpreadingFactor(SPREADING_FACTOR));
both.printf("TX power: %i dBm\n", TRANSMIT_POWER);
RADIOLIB_OR_HALT(radio.setOutputPower(TRANSMIT_POWER));
both.printf("Preamble Length: %i \n", LORA_PREAMBLE_LENGTH);
RADIOLIB_OR_HALT(radio.setPreambleLength(LORA_PREAMBLE_LENGTH));
both.printf("Coding Rate: %i \n", CODING_RATE);
RADIOLIB_OR_HALT(radio.setCodingRate(CODING_RATE));
both.printf("Sync Word: %i \n", SYNC_WORD);
RADIOLIB_OR_HALT(radio.setSyncWord(SYNC_WORD));
// Start receiving
RADIOLIB_OR_HALT(radio.startReceive(RADIOLIB_SX126X_RX_TIMEOUT_INF));
}
void loop() {
heltec_loop();
if (rxFlag) {
rxFlag = false;
radio.readData(rxdata);
if (_radiolib_status == RADIOLIB_ERR_NONE) {
both.printf("RX [%s]\n", rxdata);
both.printf(" RSSI: %.2f dBm\n", radio.getRSSI());
both.printf(" SNR: %.2f dB\n", radio.getSNR());
}
RADIOLIB_OR_HALT(radio.startReceive(RADIOLIB_SX126X_RX_TIMEOUT_INF));
}
delay(5000);
}
OUTPUT
01:12:25.969 -> ESP-ROM:esp32s3-20210327
01:12:25.969 -> Build:Mar 27 2021
01:12:25.969 -> rst:0x1 (POWERON),boot:0x8 (SPI_FAST_FLASH_BOOT)
01:12:25.969 -> SPIWP:0xee
01:12:25.969 -> mode:DIO, clock div:1
01:12:25.969 -> load:0x3fce3808,len:0x4bc
01:12:25.969 -> load:0x403c9700,len:0xbd8
01:12:25.969 -> load:0x403cc700,len:0x2a0c
01:12:25.969 -> entry 0x403c98d0
01:12:26.097 -> Radio init
01:12:26.176 -> [RadioLib] radio.begin() returned 0 (ERR_NONE)
01:12:26.176 -> Frequency: 433.00 MHz
01:12:26.208 -> [RadioLib] radio.setFrequency(433.0) returned 0 (ERR_NONE)
01:12:26.208 -> Bandwidth: 125.0 kHz
01:12:26.274 -> [RadioLib] radio.setBandwidth(125.0) returned 0 (ERR_NONE)
01:12:26.274 -> Spreading Factor: 7
01:12:26.306 -> [RadioLib] radio.setSpreadingFactor(7) returned 0 (ERR_NONE)
01:12:26.338 -> TX power: 2 dBm
01:12:26.377 -> [RadioLib] radio.setOutputPower(2) returned 0 (ERR_NONE)
01:12:26.408 -> Preamble Length: 8
01:12:26.482 -> [RadioLib] radio.setPreambleLength(8) returned 0 (ERR_NONE)
01:12:26.517 -> Coding Rate: 5
01:12:26.582 -> [RadioLib] radio.setCodingRate(5) returned 0 (ERR_NONE)
01:12:26.582 -> Sync Word: 18
01:12:26.647 -> [RadioLib] radio.setSyncWord(0x12) returned 0 (ERR_NONE)
01:12:26.648 -> [RadioLib] radio.startReceive(0xFFFFFF) returned 0 (ERR_NONE)
01:12:31.688 -> RX [��]
01:12:31.688 -> RSSI: -17.00 dBm
01:12:31.762 -> SNR: 12.75 dB
01:12:31.826 -> [RadioLib] radio.startReceive(0xFFFFFF) returned 0 (ERR_NONE)
01:12:36.862 -> RX [��]
01:12:36.912 -> RSSI: -13.00 dBm
01:12:36.928 -> SNR: 12.75 dB
01:12:36.993 -> [RadioLib] radio.startReceive(0xFFFFFF) returned 0 (ERR_NONE)
This is the library I am using for the Heltec board. The only library I could get this working with.
Solutions I have tried after going through the forums:
I have increased the transmitting power. People said low power could result in such issues.
I have tried sending a struct from one of the solutions, but again, at the receiving side, I did not get the values I was hoping. But this time atleast I didn’t get those unrecognizable characters.
People have also suggested that we should use a proper antenna. Currently I am using a wire as an antenna on the transmitter side, which I will replace with an antenna tomorrow to see if that makes a difference.
I am an absolute novice, both when it comes to using these forums and Arduino/LoRa stuff. Please help me out.
PJ