基于TMS320F28027的微弱电压测量源程序与Proteus仿真

ID:874693 · 发表于 2021-2-7 14:26

基于TMS320F28027芯片的微弱电压信号测量，熟练掌握DSP开发环境CCS软件以及Proteus电路设计软件，掌握微弱电压的测量方式，掌握TMS320F28027芯片的基本IO操作、中断方式、ADC功能的使用，进一步了解DSP系统的特点。

方案论证：

基于TMS320F28027芯片的微弱电压信号测量方案包括如下几部分：

微弱电压转换电路

为了便于对微弱电压（2*(10-3)*sin(100pi*t)）进行测量，设计运算放大电路对微弱电压进行放大处理，使得电压变为0~3.2V，电路设计如下：

电压计算公式：Vout=Rf/R*(u11-u12)；

（2）基于TMS320F28027的电压信号采集及转换

TMS320F28027的ADC功能:

1．12位双采样保持电路。

2．同时采样和序列采样方式。

3．全范围电压输入，0V到3.3V固定，或者VREFLO到VREFHI可调。

4．系统时钟全频运行，无需分频。

5．16输入通道。

6．16个SOC配置，设置触发，采样窗口，通道。

7．16个独立保存转换结果的结果寄存器。

8．多触发源。

9．9个灵活的PIE中断

ADC采集电压计算公式如下：

Vol=（AdcResult.ADCRESULT0）/4096*3.3；

（3）电压的动态显示

测量到电压后进行显示，本次实验采用LM016L型号LCD显示器进行电压显示。

引脚接口说明：

第1脚：VSS为地电源。

第2脚：VDD接5V正电源。

第3脚：VL为液晶显示器对比度调整端，接正电源时对比度最弱，接地时对比度最高。

第4脚：RS为寄存器选择，高电平时选择数据寄存器、低电平时选择指令寄存器。

第5脚：R/W为读写信号线，高电平时进行读操作，低电平时进行写操作。当RS和R/W共同为低电平时可以写入指令或者显示地址，当RS为低电平R/W为高电平时可以读忙信号，当RS为高电平R/W为低电平时可以写入数据。

第6脚：E端为使能端，当E端由高电平跳变成低电平时，液晶模块执行命令。

第7～14脚：D0～D7为8位双向数据线。

LM016L接线如下所示：

指令如下所示：

序号	指令	RS	R/W	D7	D6	D5	D4	D3	D2	D1	D0
1	清显示	0	0	0	0	0	0	0	0	0	1
2	光标返回	0	0	0	0	0	0	0	0	1	*
3	置输入模式	0	0	0	0	0	0	0	1	I/D	S
4	显示开/关控制	0	0	0	0	0	0	1	D	C	B
5	光标或字符移位	0	0	0	0	0	1	S/C	R/L	*	*
6	置功能	0	0	0	0	1	DL	N	F	*	*
7	置字符发生存贮器地址	0	0	0	1	字符发生存贮器地址
8	置数据存贮器地址	0	0	1	显示数据存贮器地址
9	读忙标志或地址	0	1	BF	计数器地址
10	写数到CGRAM或DDRAM）	1	0	要写的数据内容
11	从CGRAM或DDRAM读数	1	1	读出的数据内容

芯片时序表如下：

读状态	输入	RS=L，R/W=H，E=H	输出	D0—D7=状态字
写指令	输入	RS=L，R/W=L，D0—D7=指令码，E=高脉冲	输出	无
读数据	输入	RS=H，R/W=H，E=H	输出	D0—D7=数据
写数据	输入	RS=H，R/W=L，D0—D7=数据，E=高脉冲	输出	无

系统设计：

系统框图

（2）程序流程图

电路及程序

电路设计如下：

程序如下所示：

#include "DSP28x_Project.h" // Device Headerfile and Examples Include File
// Prototype statements for functions found within this file.
interrupt void adc_isr(void);
void Gpio_select(void);
void IOint();
void CMDWrite(unsigned char cm );
void DataWrite(unsigned char dt);
void lcdinit();
// Global variables used in this example:
//Uint16 LoopCount;
//Uint16 ConversionCount;
//Uint16 TempSensorVoltage[10];
Uint32 Volage=0;
double vol=0;
int16 bit1[3]={0};
Uint16 flag=0;
unsigned data='0';
void main()
{
// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP2802x_SysCtrl.c file.
InitSysCtrl();
Gpio_select();
// Step 2. Initialize GPIO:
// This example function is found in the DSP2802x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
// InitGpio(); // Skipped for this example
// Step 3. Clear all interrupts and initialize PIE vector table:
// Disable CPU interrupts
DINT;
// Initialize the PIE control registers to their default state.
// The default state is all PIE interrupts disabled and flags
// are cleared.
// This function is found in the DSP2802x_PieCtrl.c file.
InitPieCtrl();
// Disable CPU interrupts and clear all CPU interrupt flags:
IER = 0x0000;
IFR = 0x0000;
// Initialize the PIE vector table with pointers to the shell Interrupt
// Service Routines (ISR).
// This will populate the entire table, even if the interrupt
// is not used in this example. This is useful for debug purposes.
// The shell ISR routines are found in DSP2802x_DefaultIsr.c.
// This function is found in DSP2802x_PieVect.c.
InitPieVectTable();
// Interrupts that are used in this example are re-mapped to
// ISR functions found within this file.
EALLOW; // This is needed to write to EALLOW protected register
PieVectTable.ADCINT1 = &adc_isr;
EDIS; // This is needed to disable write to EALLOW protected registers
// Step 4. Initialize the ADC:
// This function is found in DSP2802x_Adc.c
InitAdc(); // For this example, init the ADC
// Step 5. Configure ADC to sample the temperature sensor on ADCIN5:
// The output of Piccolo temperature sensor can be internally connected to the ADC through ADCINA5
// via the TEMPCONV bit in the ADCCTL1 register. When this bit is set, any voltage applied to the external
// ADCIN5 pin is ignored.
//EALLOW;
//AdcRegs.ADCCTL1.bit.TEMPCONV = 1; //Connect internal temp sensor to channel ADCINA5.
//EDIS;
// Step 6. Continue configuring ADC to sample the temperature sensor on ADCIN5:
// Since the temperature sensor is connected to ADCIN5, configure the ADC to sample channel ADCIN5
// as well as the ADC SOC trigger and ADCINTs preferred. This example uses EPWM1A to trigger the ADC
// to start a conversion and trips ADCINT1 at the end of the conversion.
EALLOW;
AdcRegs.ADCCTL1.bit.INTPULSEPOS = 1; //ADCINT1 trips after AdcResults latch
AdcRegs.ADCCTL1.bit.ADCBGPWD=1;
AdcRegs.ADCCTL1.bit.ADCPWDN=1;
AdcRegs.ADCCTL1.bit.ADCENABLE=1;
AdcRegs.ADCCTL1.bit.ADCREFSEL=0;
EDIS;
//DELAY_US(ADC_usDELAY);
EALLOW;
AdcRegs.INTSEL1N2.bit.INT1E = 1; //Enabled ADCINT1
//AdcRegs.INTSEL1N2.bit.INT1CONT = 0; //Disable ADCINT1 Continuous mode
//AdcRegs.INTSEL1N2.bit.INT1SEL = 0; //setup EOC0 to trigger ADCINT1 to fire
AdcRegs.ADCSOC0CTL.bit.CHSEL = 0; //set SOC0 channel select to ADCINA5 (which is internally connected to the temperature sensor)
AdcRegs.ADCSOC0CTL.bit.TRIGSEL = 5; //set SOC0 start trigger on EPWM1A
AdcRegs.ADCSOC0CTL.bit.ACQPS = 6; //set SOC0 S/H Window to 7 ADC Clock Cycles, (6 ACQPS plus 1)
EDIS;
// Step 7. User specific code, enable interrupts:
// Enable ADCINT1 in PIE
PieCtrlRegs.PIEIER1.bit.INTx1 = 1; // Enable INT 1.1 in the PIE
IER |= M_INT1; // Enable CPU Interrupt 1
EINT; // Enable Global interrupt INTM
ERTM; // Enable Global realtime interrupt DBGM
// LoopCount = 0;
//ConversionCount = 0;
// Assumes ePWM1 clock is already enabled in InitSysCtrl();
EPwm1Regs.ETSEL.bit.SOCAEN = 1; // Enable SOC on A group
EPwm1Regs.ETSEL.bit.SOCASEL = 4; // Select SOC from from CPMA on upcount
EPwm1Regs.ETPS.bit.SOCAPRD = 1; // Generate pulse on 1st event
EPwm1Regs.CMPA.half.CMPA = 0x0080; // Set compare A value
EPwm1Regs.TBPRD = 0xFFFF; // Set period for ePWM1
EPwm1Regs.TBCTL.bit.CTRMODE = 0; // count up and start
// Wait for ADC interrupt
IOint();
lcdinit();
//DataWrite(1);
for(;;)
{
if(flag==1)
{
flag=0;
CMDWrite(0x80);
if(bit1[0]>0)
{
DataWrite('+');
DataWrite('0');
DataWrite('.');
DataWrite('0');
DataWrite('0');
DataWrite(abs(bit1[2])+'0');
DataWrite(abs(bit1[1])+'0');
DataWrite(abs(bit1[0])+'0');
}
else
{
DataWrite('-');
DataWrite('0');
DataWrite('.');
DataWrite('0');
DataWrite('0');
DataWrite(abs(bit1[2])+'0');
DataWrite(abs(bit1[1])+'0');
DataWrite(abs(bit1[0])+'0');
}
}
}
}
interrupt void adc_isr(void)
{
//TempSensorVoltage[ConversionCount] = AdcResult.ADCRESULT0;
Volage= AdcResult.ADCRESULT0;
vol=(3.3/4096*Volage+1.6)/800-0.004;
bit1[0] = ((int32)(vol*100000))%10;
bit1[1] = ((int32)(vol*10000))%10;
bit1[2] = ((int32)(vol*1000))%10;
AdcRegs.ADCINTFLGCLR.bit.ADCINT1 = 1; //Clear ADCINT1 flag reinitialize for next SOC
PieCtrlRegs.PIEACK.all = PIEACK_GROUP1; // Acknowledge interrupt to PIE
flag=1;
return;
}
void Gpio_select(void)
{
EALLOW;
GpioCtrlRegs.GPAMUX1.all = 0x00000000; // All GPIO
GpioCtrlRegs.GPAMUX2.all = 0x00000000; // All GPIO
GpioCtrlRegs.GPAMUX1.all = 0x00000000; // All GPIO
GpioCtrlRegs.GPADIR.all = 0xFFFFFFFF; // All outputs
GpioCtrlRegs.GPBDIR.all = 0x0000000F; // All outputs
EDIS;
}
void IOint()
{
EALLOW;
GpioCtrlRegs.GPAPUD.all=0;
GpioDataRegs.GPASET.all=1;
GpioCtrlRegs.GPAMUX1.all=0;
GpioCtrlRegs.GPADIR.all=0;
GpioCtrlRegs.GPBPUD.bit.GPIO32 = 0; // Enable pullup on GPIO6 //RS
GpioDataRegs.GPBSET.bit.GPIO32= 1; // Load output latch
GpioCtrlRegs.GPBMUX1.bit.GPIO32 = 0; // GPIO6 = GPIO6
GpioCtrlRegs.GPBDIR.bit.GPIO32 = 1;
GpioCtrlRegs.GPBPUD.bit.GPIO33 = 0; // Enable pullup on GPIO6 //RW
GpioDataRegs.GPBSET.bit.GPIO33= 1; // Load output latch
GpioCtrlRegs.GPBMUX1.bit.GPIO33 = 0; // GPIO6 = GPIO6
GpioCtrlRegs.GPBDIR.bit.GPIO33 = 1;
GpioCtrlRegs.GPBPUD.bit.GPIO34 = 0; // Enable pullup on GPIO6 //E
GpioDataRegs.GPBSET.bit.GPIO34= 1; // Load output latch
GpioCtrlRegs.GPBMUX1.bit.GPIO34 = 0; // GPIO6 = GPIO6
GpioCtrlRegs.GPBDIR.bit.GPIO34 = 1;
EDIS;
}
void CMDWrite(unsigned char cm )
{
GpioDataRegs.GPBDAT.bit.GPIO32=0;
GpioDataRegs.GPADAT.all=cm;
DELAY_US(2);
GpioDataRegs.GPBDAT.bit.GPIO34=1;
DELAY_US(2);
GpioDataRegs.GPBDAT.bit.GPIO34=0;
}
void DataWrite(unsigned char dt)
{
GpioDataRegs.GPBDAT.bit.GPIO32=1;
GpioDataRegs.GPADAT.all=dt;
DELAY_US(2);
GpioDataRegs.GPBDAT.bit.GPIO34=1;
DELAY_US(2);
GpioDataRegs.GPBDAT.bit.GPIO34=0;
}
void lcdinit()
{
GpioDataRegs.GPBDAT.bit.GPIO33=0;
GpioDataRegs.GPBDAT.bit.GPIO34=0;
CMDWrite(0x38);
CMDWrite(0x06);
CMDWrite(0x0c);
}