WiFi_433_Transceiver/main/transceiver.c

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <sys/time.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_sleep.h"
#include "esp_log.h"
#include "driver/uart.h"
#include "driver/rtc_io.h"
#include "esp_intr_alloc.h"
#include "esp_attr.h"
#include "driver/timer.h"
#include <stddef.h>
#include "esp_intr_alloc.h"

#include "transceiver.h"
#include "rxTimer.h"


bool disableRx = true; // Controls if trcv is in RX or TX-mode

void trcvSendHighLowPulse(uint32_t high, uint32_t low) {

  if( disableRx == false ) return;
  
  gpio_set_level(GPIO_TX_DATA, 1);
  delayMicroseconds( high ); 
  gpio_set_level(GPIO_TX_DATA, 0);
  delayMicroseconds( low );  
}

void initTransceiver() {

    gpio_set_level(GPIO_ENABLE, 0);
    gpio_set_level(GPIO_TX_ENABLE, 0);
    gpio_set_level(GPIO_TX_DATA, 0);

    gpio_pad_select_gpio(GPIO_ENABLE);
    gpio_pad_select_gpio(GPIO_TX_ENABLE);
    gpio_pad_select_gpio(GPIO_TX_DATA);
    gpio_pad_select_gpio(GPIO_RX_DATA);

    gpio_set_direction(GPIO_ENABLE, GPIO_MODE_OUTPUT);
    gpio_set_direction(GPIO_TX_ENABLE, GPIO_MODE_OUTPUT);
    gpio_set_direction(GPIO_TX_DATA, GPIO_MODE_OUTPUT);
    gpio_set_direction(GPIO_RX_DATA, GPIO_MODE_INPUT);

    // ------------------ INIT THE TRANCEIVER -------------------------
    // From powerdown mode (pin 4-5-6 low), 
    // 1. Drive high pin 6 (ENABLE)
    // 2. After 20us drive high pin 5 (RX/TX)200us, hold on 40us 
    // 3. Drive down 20us pin 6 (ENABLE).  
    gpio_set_level(GPIO_ENABLE, 1); delayMicroseconds( 20 ); 
    gpio_set_level(GPIO_TX_ENABLE, 1); delayMicroseconds( 200 ); gpio_set_level(GPIO_TX_ENABLE, 0);
    delayMicroseconds( 40 ); 
    gpio_set_level(GPIO_ENABLE, 0); delayMicroseconds( 20 ); gpio_set_level(GPIO_ENABLE, 1);  
    delayMicroseconds( 200 );
    // ------------------ INIT THE TRANCEIVER -------------------------  
            
    ESP_LOGI("TRCV", "Transceiver has been initialized.");
}

void trcvSwitch2transmit() {

  disableRx = true;
  // ------------------ GO TO TRANSMIT STATE -------------------------
  gpio_set_level(GPIO_TX_ENABLE, 1);
  delayMicroseconds( 400 );
  // ------------------ GO TO TRANSMIT STATE -------------------------
}

void trcvSwitch2receive() {
  // ------------------ GO TO RECEIVE STATE -------------------------
  // From Transmission Mode to Receiver Mode follow the procedure:
  // Drive down pin 5 (RX/TX), after 40us drive down pin 6 (ENABLE) 20us long.
  //After 200 us the device is ready for reception.
  gpio_set_level(GPIO_TX_ENABLE, 0); 
  delayMicroseconds( 40 ); 
  gpio_set_level(GPIO_ENABLE, 0); 
  delayMicroseconds( 20 ); 
  gpio_set_level(GPIO_ENABLE, 1);  
  delayMicroseconds( 200 );
  // ------------------ GO TO RECEIVE STATE -------------------------
  disableRx = false;
}