MSP430 Learning Notes 10-ADC Collection 1602 Display

This is also a routine in the development board, with explanations of the key points. The program is as follows:

1. /********************************************************* 

2. Program notes: 

3. First, you can choose whether to turn on the internal reference voltage or use the external reference voltage 

4. Each channel can independently select the reference voltage 

5. If an external reference voltage is connected, be careful to turn off the internal reference voltage to prevent damage 

6. Microcontroller 

7.  

8. Program function: The MCU's on-chip ADC converts the voltage of the P6.0 port 

9.           The analog voltage value is displayed on the 1602 LCD. 

10. ---------------------------------------------------------- 

11. Dip switch setting: turn LCD to ON and other positions to OFF 

12. Test instructions: Adjust the knob of potentiometer W1 and observe the changes in the numbers displayed on the LCD. 

13. *********************************************************/  

14. #include    

15. #include  "cry1602.h"  

16. #include  "cry1602.c"  

17.   

18. //typedef unsigned char uchar;  

19. //typedef unsigned int  uint;  

20.   

21. #define   Num_of_Results   32  

22.   

23. fly shuzi[] = {"0123456789."};  

24. uchar tishi[] = {"The volt is:"};  

25.   

26. static uint results[Num_of_Results]; //Array to save ADC conversion results                                                      

27. void Trans_val(uint Hex_Val);             

28. /****************************Main function********************************/  

29. void main(void)  

30. {  

31.     WDTCTL = WDTPW+WDTHOLD; //Turn off the watchdog  

32.   

33.     /*The following six lines of code close all IO ports*/  

34.     P1DIR = 0XFF;P1OUT = 0XFF;  

35.     P2DIR = 0XFF;P2OUT = 0XFF;  

36.     P3DIR = 0XFF;P3OUT = 0XFF;  

37.     P4DIR = 0XFF;P4OUT = 0XFF;  

38.     P5DIR = 0XFF;P5OUT = 0XFF;  

39.     P6DIR = 0XFF;P6OUT = 0XFF;  

40.   

41.     P6DIR |= BIT2;P6OUT |= BIT2; //Disable level conversion  

42.     LcdReset(); //Reset 1602 LCD  

43.     DispNChar(2,0,12,tishi); //Display prompt information  

44.     Disp1Char(11,1,'V'); //Display voltage unit  

45.     P6SEL |= BIT0; // Enable ADC channel  

46.     ADC12CTL0 = ADC12ON+SHT0_8+MSC; // Turn on ADC and set sampling time  

47.     // The above configuration does not turn on the internal reference voltage  

48.     //ADC12MCTLx is used to select the channel and reference voltage. This register is not configured to the default value.  

49.     // The default value is that the reference voltage is selected as AVCC (3.3V), the channel is A0, so the measurement range is 0-3.3V  

50.     ADC12CTL1 = SHP+CONSEQ_2; // Use sampling timer  

51.     //When the register configuration sample hold trigger source is selected, ADC12SC is used to collect the signal generated by the sampling timing circuit.  

52.     // The conversion mode is single-channel repeated conversion. The above settings must be set when ENC=0  

53.     ADC12IE = BIT0; // Enable ADC interrupt  

54.     ADC12CTL0 |= ENC; // Enable conversion  

55.     ADC12CTL0 |= ADC12SC; // Start conversion  

56.     _EINT(); // Enable global interrupt  

57.     LPM0;  

58. }  

59.   

60. /******************************************* 

61. Function name: ADC12ISR 

62. Function: ADC interrupt service function, here we use multiple averages 

63.           Calculate the analog voltage value of P6.0 port 

64. Parameters: None        

65. Return value: None 

66. ********************************************/  

67. #pragma vector=ADC_VECTOR  

68. __interrupt void ADC12ISR (void)  

69. {  

70.     static uint index = 0;  

71.   

72.     results[index++] = ADC12MEM0; // Store the conversion results into the array  

73.     if(index == Num_of_Results) //If the array is full  

74.     {  

75.         flying i;  

76.         unsigned long sum = 0;  

77.   

78.         index = 0; //Start saving from the beginning, the original data will be overwritten  

79.     for(i = 0; i < Num_of_Results; i++) //Calculate and  

80.     {  

81.         sum += results[i];  

82.     }  

83.     sum >>= 5; //divide by 32  

84.     Trans_val(sum);  

85.     }  

86. }  

87.   

88. /******************************************* 

89. Function name: Trans_val 

90. Function: Convert hexadecimal ADC data into three-digit decimal 

91.           Real analog voltage data, and displayed on LCD 

92. Parameter: Hex_Val--hexadecimal data 

93.           n--The denominator of the transformation is equal to 2 to the power of n        

94. Return value: None 

95. ********************************************/  

96. void Trans_val(uint Hex_Val)  

97. {  

98.     unsigned long caltmp;  

99.     uint Curr_Volt;  

100.     fly t1,i;  

101.     float ptr[4];  

102.   

103.     caltmp = Hex_Val;  

104.     caltmp = (caltmp << 5) + Hex_Val;           //caltmp = Hex_Val * 33  

105.     caltmp = (caltmp << 3) + (caltmp << 1);     //caltmp = caltmp * 10  

106.     Curr_Volt = caltmp >> 12;                   //Curr_Volt = caltmp / 2^n  

107.     // The reference voltage is 3.3V, so the calculation formula should be Hex_val*3.3/2^n   

108.     // Multiplication and division calculations can be performed by shifting to effectively improve program running efficiency  

109.     ptr[0] = Curr_Volt / 100; //Hex->Dec conversion  

110.     t1 = Curr_Volt - (ptr[0] * 100);  

111.     ptr[2] = t1 / 10;  

112.     ptr[3] = t1 - (ptr[2] * 10);  

113.     ptr[1] = 10; //The 10th bit in the shuzi table corresponds to the symbol "."  

114.     //Display the transformed result on the LCD  

115.     for(i = 0;i < 4;i++)  

116.         Disp1Char((6 + i),1,shuzi[ptr[i]]);  

117. }