Hello,
I am currently using the Heltec Wireless Stick V3 module for a project. This project requires both transmitting and receiving messages via LoRa, as well as using a TFT screen (model 2.0 TFT SPI ver1.1) that operates with the SPI protocol.
However, I have encountered a problem: the default configuration of the Heltec board reserves the pins used by the LoRa module, preventing me from properly connecting the pins of my TFT screen. To work around this, I used alternative pins to connect the screen and modified the SPI bus using the SPIClass class.
When I specify a new SPI bus with the command SPIClass mySPI1(2) , the TFT screen does not work, but the LoRa module functions correctly. Conversely, if I do not modify the SPI bus (i.e., I do not define SPIClass mySPI1(2) ), the TFT screen works properly, but the LoRa module stops functioning.
For this project, it is essential that I use both the LoRa module and the TFT screen, which share the SPI protocol. As I am new to Heltec boards, I would greatly appreciate your assistance in resolving this issue.
Thank you in advance for your help.
Code:
"#include “LoRaWan_APP.h”
#include “Arduino.h”
#include <Adafruit_GFX.h> // graphics library
#include <Adafruit_ST7789.h> // library for this display
#include <SPI.h>
#include <Adafruit_MPU6050.h>
#include <Adafruit_Sensor.h>
////////////////////////////// LoRa variable init//////////////////////////////////////////////
#define RF_FREQUENCY 868E6 // Hz
#define TX_OUTPUT_POWER 14 // dBm
#define LORA_BANDWIDTH 0
#define LORA_SPREADING_FACTOR 7
#define LORA_CODINGRATE 1
#define LORA_PREAMBLE_LENGTH 8 // Same for Tx and Rx
#define LORA_SYMBOL_TIMEOUT 0 // Symbols
#define LORA_FIX_LENGTH_PAYLOAD_ON false
#define LORA_IQ_INVERSION_ON false
#define RX_TIMEOUT_VALUE 1000
#define BUFFER_SIZE 30 // Define the payload size here
////////////////////////////// TFT variable init//////////////////////////////////////////////
#define TFT_CS 34 // CS pin
#define TFT_RST 47 // reset pin
#define TFT_DC 48 // data pin
#define TFT_SCK 36 // data pin
#define TFT_MISO 37 // data pin
#define TFT_MOSI 35 // data pin
#define ID “#04”
////////////////////////////// TFT variable init//////////////////////////////////////////////
#define SHOCK_DIG 4
#define SHOCK_ANA 5
Adafruit_ST7789 tft = Adafruit_ST7789(TFT_CS, TFT_DC, TFT_RST);
const String MES_ALERTE = “Z0Z04”;
char txpacket[BUFFER_SIZE];
char rxpacket[BUFFER_SIZE];
char vol[BUFFER_SIZE];
char volM[BUFFER_SIZE];
char volC[BUFFER_SIZE];
static RadioEvents_t RadioEvents;
int16_t txNumber;
int16_t rssi,rxSize;
bool lora_idle = true;
bool stateDanger = false;
bool stateNew = false;
void OnRxDone( uint8_t *payload, uint16_t size, int16_t rssi, int8_t snr);
void setup() {
Serial.begin(115200);
//Mcu.begin(WIRELESS_STICK_V3,SLOW_CLK_TPYE);
///////////////////////////////TFT///////////////////////////////////////////
SPIClass mySPI1(2); // Exemple : SPI secondaire
mySPI1.begin(TFT_SCK,TFT_MISO,TFT_MOSI,TFT_CS); //(SCK, MISO, MOSI, SS)
tft.init(240, 320, SPI_MODE3);
tft.setRotation(2);
pinMode(BUZZER, OUTPUT);
txNumber=0;
rssi=0;
//--------------------Initialisation of Lora------------------------//
RadioEvents.RxDone = OnRxDone;
Radio.Init( &RadioEvents );
Radio.SetChannel( RF_FREQUENCY );
Radio.SetRxConfig( MODEM_LORA, LORA_BANDWIDTH, LORA_SPREADING_FACTOR,
LORA_CODINGRATE, 0, LORA_PREAMBLE_LENGTH,
LORA_SYMBOL_TIMEOUT, LORA_FIX_LENGTH_PAYLOAD_ON,
0, true, 0, 0, LORA_IQ_INVERSION_ON, true );
}
void loop(){
tft.fillScreen(ST77XX_BLACK); // fills the screen with black colour
tft.setCursor(10, 10); // starts to write text at y10 x10
tft.setTextColor(ST77XX_WHITE); // text colour to white you can use hex codes like 0xDAB420 too
tft.setTextSize(3); // sets font size
tft.setTextWrap(true);
tft.print(“HELLO WORLD!”);
delay(2000);
tft.fillScreen(ST77XX_BLACK);
tft.setCursor(10, 10);
tft.setTextSize(3); // sets font size
tft.setTextColor(ST77XX_RED);
tft.print(“TOTO!”);
delay(2000);
Serial.println(“ok”);
if(lora_idle)
{
lora_idle = false;
Serial.println(“into RX mode”);
Radio.Rx(0);
}
Radio.IrqProcess();
//Serial.println(rxpacket);
}
void OnRxDone( uint8_t *payload, uint16_t size, int16_t rssi, int8_t snr )
{
rssi=rssi;
rxSize=size;
memcpy(rxpacket, payload, size );
rxpacket[size]=’\0’;
Radio.Sleep( );
Serial.printf("\r\nreceived packet “%s” with rssi %d , length %d\r\n",rxpacket,rssi,rxSize);
lora_idle = true;
strcpy(vol,rxpacket);
}
"