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  1. /*
  2.  * File:   TempSensor.c
  3.  * Author: narayan
  4.  *
  5.  * Created on 15 de Março de 2019, 22:29
  6.  */
  7.  
  8. #ifndef F_CPU
  9. #   define F_CPU 20000000UL / 8
  10. #endif
  11.  
  12. #include <stdlib.h>
  13. #include <inttypes.h>
  14. #include <avr/io.h>
  15. #include <util/delay.h>
  16. #include <string.h>
  17.  
  18. #include "usart.h"
  19.  
  20. /*
  21.  *
  22.  */
  23.  
  24. #define WRITE_OP    (0x00 << 0x00)
  25. #define READ_OP     (0x01 << 0x00)
  26.  
  27. //Statuses handling
  28. #define STATUS_NACK 1
  29. #define STATUS_ACK  0
  30. #define STATUS_OK   0
  31.  
  32. #define ARBLOST    -1
  33. #define BUSRROR    -2
  34.  
  35. void CPU_Init(void){
  36.    // Enable Protected registers write
  37.    CPU_CCP = CCP_IOREG_gc;
  38.    CLKCTRL_MCLKCTRLA = CLKCTRL_CLKSEL_OSC20M_gc;
  39.  
  40.    // Eable Prescaler
  41.    CPU_CCP = CCP_IOREG_gc;
  42.    CLKCTRL_MCLKCTRLB = CLKCTRL_PDIV_8X_gc | CLKCTRL_PEN_bm;
  43.    CPU_SREG |= CPU_I_bm; // Global Interrupt Flag Enabled
  44. }
  45.  
  46. void TWI_Init(void){
  47.    TWI0_CTRLA |=  TWI_SDASETUP_4CYC_gc     // SDASETUP time of 4 clock cycles
  48.                 | TWI_SDAHOLD_500NS_gc;    // SDA Hold time - Meets SMBus specifications across all corners (0x03) ???
  49.    TWI0_CTRLA &= ~TWI_FMPEN_bm;            // Fast Mode Plus disabled
  50.  
  51.    // Set MBAUD to get 100KHz for SCL from fSCL = CLK_PER / (10 + 2*BAUD + CLK_PER*tRise)
  52.    // fSCL = 104KHz, CLK_PER = 20MHz/8, tRise = 2.5ns (datasheet page 17)
  53.    TWI0_MBAUD = 0x07;
  54.    TWI0_MCTRLB |=  TWI_FLUSH_bm;           // Clear TWI state
  55. 	TWI0_MSTATUS |= TWI_RIF_bm             // Set RIF
  56.                  | TWI_WIF_bm              // Set WIF
  57.                  | TWI_BUSSTATE_IDLE_gc;   // Manually set BUS state to IDLE
  58.    TWI0_MCTRLA &= ~TWI_TIMEOUT_gm;         // Disable Timeout for TWI operation
  59.    TWI0_MCTRLA |=  TWI_SMEN_bm             // Smart Mode Enable
  60.                  | TWI_ENABLE_bm;          // Enable Master Mode of operation
  61. }
  62.  
  63. void Start_Bit(void){
  64.    // Wait until BUS is IDLE
  65.    while( (TWI0_MSTATUS & TWI_BUSSTATE_gm) != TWI_BUSSTATE_IDLE_gc)
  66.       /*wait*/;
  67.  
  68.    // Send Start Bit
  69.    TWI0_MCTRLB = TWI_MCMD_REPSTART_gc;
  70. }
  71.  
  72. void Stop_Bit(void){
  73.    // Wait until BUS is IDLE
  74.    while( (TWI0_MSTATUS & TWI_BUSSTATE_gm) != TWI_BUSSTATE_IDLE_gc)
  75.       /*wait*/;
  76.  
  77.    TWI0_MCTRLB = TWI_MCMD_STOP_gc;
  78. }
  79.  
  80. uint8_t TWI_Read(uint8_t sl_addr, uint8_t* packet, uint8_t* psumtemp, float* pavgtemp){
  81.    if( (TWI0_MSTATUS & TWI_BUSERR_bm) || (TWI0_MSTATUS & TWI_ARBLOST_bm) ){
  82.       TWI0_MCTRLA &= ~TWI_ENABLE_bm;
  83.       _delay_ms(1);
  84.       TWI0_MCTRLA |= TWI_ENABLE_bm;
  85.       TWI0_MCTRLA |= TWI_BUSSTATE_IDLE_gc;
  86.    }
  87.  
  88.    // Send Slave address and R operation onto the bus
  89.    TWI0_MADDR = (sl_addr << 1) | READ_OP;
  90.  
  91.    for(uint8_t i = 0; i < 5; i++){
  92.       // Data byte is stored into TWI0_DATA register and passed to *packet variable
  93.       *(packet + i) = TWI0_MDATA;
  94.       // Sum the read value
  95.       *psumtemp += *(packet + i);
  96.       // Average readed values
  97.       *pavgtemp = *psumtemp / 5.0;
  98.       if(i == 5){
  99.          // Stop reading more data bytes with a NACK
  100.          TWI0_MCTRLB = TWI_ACKACT_NACK_gc;
  101.          break;
  102.       }
  103.       // Send ACK from Master to signal Data packed readed
  104.       TWI0_MCTRLB = TWI_ACKACT_ACK_gc;
  105.    }
  106.  
  107.    // Send Stop bit to terminate transaction
  108.    TWI0_MCTRLB = TWI_MCMD_STOP_gc;
  109.  
  110.    return STATUS_OK;
  111. }
  112.  
  113. int main(int argc, char** argv) {
  114.  
  115.    uint8_t temperature[256] = {0};
  116.    uint8_t sumtemp = 0;
  117.    float avgtemp = 0.0;
  118.    char message[256];
  119.  
  120.    CPU_Init();
  121.    USART2_Init();
  122.    TWI_Init();
  123.  
  124.    while(0x01){
  125.       TWI_Read(0x18, temperature, &sumtemp, &avgtemp);
  126.       USART2_SendStr(itoa(avgtemp, message, 10));
  127.       USART2_SendChar('\n');
  128.       _delay_ms(1000);
  129.    }
  130.  
  131.    return (EXIT_SUCCESS);
  132. }
Compilation error #stdin compilation error #stdout 0s 0KB
comments (?)
stdin
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Standard input is empty
compilation info 
prog.c:14:20: fatal error: avr/io.h: No such file or directory
 #include <avr/io.h>
                    ^
compilation terminated.
stdout
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Standard output is empty
https://ideone.com/4GVVf4
5 temp reads
language:
C (gcc 8.3)
created:
4 years ago
visibility:
secret

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