Transmitter

#include <avr/io.h>
#include <util/delay.h>
#include <avr/interrupt.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include "nRF24l01/nRF24L01.h"
#include "UART/Uart.h"                  // UART library
#include "Terminal/terminal.h"          // Terminal library using UART
#include "OLED/OLED.h"                  // 128x64 OLED library

// Receiving function
void RX_function ( void * nRF_RX_buff , uint8_t len );

// ADC measurement function
uint8_t measurement(uint8_t channel);

// maping function
//uint32_t map(uint32_t x, uint32_t in_min, uint32_t in_max, uint32_t out_min, uint32_t out_max);

// variables using for convert ADC measurement to voltage
uint8_t IntegerPart = 0, FractionPart = 0;
uint32_t Voltage = 0;

//Flag buffer
uint8_t nRF_Flag = 0;

// Flags and other variables
uint8_t XPotentiometerVoltage = 0, YPotentiometerVoltage = 0;
//volatile uint8_t ms10_counter, ms10_delay_flag, seconds, seconds_flag;    // for setting delays

int main (void)
{
    // UART initialization
    USART_Init(_UBRR);

    // nRF24L01+ initialization
    nRF_init();
    register_nRF_RX_Event_Callback(RX_function);

    //OLED initialization
    //OLED_init( SSD1306_SWITCHCAPVCC, REFRESH_MID );
    //OLED_Clear();

    // ADC settings
    ADMUX |= (1<<REFS1) | (1<<REFS0) | (1<<ADLAR) ;                 // Vref = 2.56V, ADLAR using for read just one byte from ADC measurement
    ADCSRA |= (1<<ADEN) | (1<<ADPS2) | (1<<ADPS1) | (1<<ADPS0);     // ADC enable, ADC interrupt enable Prescaler 128 ( sampling freq = 16MHz / 128 )

    // TIMER0 (delays) configuration
//  TCCR0 |= (1<<WGM01);                // CTC
//  TCCR0 |= (1<<CS02)|(1<<CS00);       // prescaler = 1024
//  OCR0 = 155;                         // 16MHz / 1024 / 156 ~= 100Hz ( 10 ms )
//  TIMSK |= (1<<OCIE0);                // Timer0 enable

    // permit for interrupts
    sei();

    // Variables
    char Buffer[32];

    while(1)
    {
        if ( nRF_Flag == 0)
        {
                XPotentiometerVoltage = measurement(PA1);
                memset(Buffer, '\0', 32);
                sprintf(Buffer, "Xaxis%d", XPotentiometerVoltage);
                nRF_SendDataToAir(Buffer);

                YPotentiometerVoltage = measurement(PA0);
                memset(Buffer, '\0', 32);
                sprintf(Buffer, "Yaxis%d", YPotentiometerVoltage);
                nRF_SendDataToAir(Buffer);

                memset(Buffer, '\0', 32);
                strcpy(Buffer, "TX");
                nRF_SendDataToAir(Buffer);
        }

//      if ( RX_Flag == 1 )
//      {
////            if ( RXFlag == 1 )
////            {
////                nRF_RX_Power_Up();
////                RXFlag = 0;
////            }
//
//          nRF_RX_EVENT();
//      }


//      OLED_SendString(0, 35, "Voltage: " ,1, 1, 0);
//      OLED_SendInt(0, 35, IntegerPart, 1, 1, 0);
//      OLED_SendString(0, strlen("Voltage: ")+1, "." ,1, 1, 0);
//      OLED_SendInt(0, strlen("Voltage: ")+2, FractionPart, 1, 1, 0);
//      OLED_SendString(0, 35, "                             " ,1, 1, 0);

//      OLED_Display();
    }

}

void RX_function ( void * nRF_RX_buff, uint8_t len )
{
    char BufferForNumbers[32] = "";
    char key[] = "0123456789";                      //key using to searching numbers in received commands
    char *pointer;

    uint8_t BufferIndexIncrement = 0;

    //data parsing
    if (strncmp(nRF_RX_buff, "Vol", 3) == 0)    // if received data contains "Xaxis"
    {
        pointer = strpbrk(nRF_RX_buff, key);        // strpbrk returns pointer to the first searching character

            while( pointer != NULL )
            {
                BufferForNumbers[BufferIndexIncrement++] = *pointer;
                pointer = strpbrk(pointer+1, key);
            }

//      Voltage = atoi(BufferForNumbers) * 25 * 2;
//      IntegerPart = Voltage / 10000;
//      FractionPart = ( Voltage / 100 ) % 100;
    }

    if (strncmp(nRF_RX_buff, "TX", 2) == 0)
    {
        nRF_Flag = 0;
        _delay_ms(3);
    }

//  if (nRF_RX_buff != 0) nRF_Clear_RX();

    PORTA ^= (1<<PA3);

}

uint8_t measurement(uint8_t channel)
{
    ADMUX = (ADMUX & 0xF8) | channel;   // choosen ADC channel

    ADCSRA |= (1<<ADSC);                // measurement

    while( ADCSRA & (1<<ADSC) );        // wait until conversion ends

    return ADCH;                        // result from ADCH
}

//uint32_t map(uint32_t x, uint32_t in_min, uint32_t in_max, uint32_t out_min, uint32_t out_max)
//{
//  return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
//}

// Timer using for delays
//ISR(TIMER0_COMP_vect)
//{
//  ms10_delay_flag = 1;                // set flag in every 10ms
//
//  if ( ++ms10_counter > 99)           // if one second reached
//  {
//      seconds_flag = 1;               // set second flag
//      seconds++;
//      if( seconds > 59 ) seconds = 0; // if one minute reached
//      ms10_counter = 0;
//  }
//}