Part Number: MSP430F5529
Hello,
so I just want to read a value of a voltage on pin P6.5(A5) in a while loop with delay.
My clock is initialized as 20MHz for MCLK, 10 MHz for SMCLK, and 32k for ACLK and they are all tested (I actually completed a graphical LCD driver based on SPI based on this clock which guarantees it is working properly)
that's the code :
void ADC_init(void)
{
P6SEL|=0x20; //P6.5 is not GPIO
P8DIR&=~0x20; //P6.5 is output
ADC12CTL0&=~0x0002; //ADC12_A disable conversion ADC12ENC
ADC12CTL0&=~0x0010; //ADC12_A is off ADC12ON
ADC12CTL0|=0x0400; //sample-and-hold time = 64 ADC12CLK cycles
//The sampling timer requires a rising edge of the SHI signal to trigger each sample-and-convert.
REFCTL0&=~0x0080; //REFMSTR=0, Reference system controlled by legacy control bits inside the ADC12_A module when available
ADC12CTL0|=0x0020; //ADC12_A reference generator on. In devices with the REF module, this bit is only valid if the REFMSTR bit of the REF module is set to 0
ADC12CTL0|=0x0040; //ADC12_A is the reference generator voltage and = 2.5V,this bit is only valid if the REFMSTR bit of the REF module is set to 0
//ADC12SC start sample and conversion
ADC12CTL1|=0x5000; //conversion start address is ADC12MEM5
//ADC12_A sample-and-hold source select is ADC12SC bit
//ADC12_A sample-and-hold pulse-mode select : SAMPCON signal is sourced from the sample-input signal
ADC12CTL1|=0x00E0; //ADC12_A clock divider by 8
ADC12CTL1|=0x0180; //ADC12_A clock source is SMCLK
//Single-channel, single-conversion
ADC12CTL2|=0x0100; //ADC12_A predivider. This bit predivides the selected ADC12_A clock source Predivide by 4
ADC12CTL2|=0x0080; //Temperature sensor off
ADC12MCTL5|=0x0010; ADC12MCTL5&=~0x0060; //VR+ = VREF+ and VR- = AVSS
ADC12MCTL5|=0x0005; ADC12MCTL5&=~0x0009;//channel select is A5
__delay_cycles(100000);
}
unsigned short ADC_READ(void)
{
unsigned short value=0;
ADC12CTL0|=0x0010; //ADC12_A is On ADC12ON
ADC12CTL0|=0x0001; //start sample and conversion ADC12SC
ADC12CTL0|=0x0002; //ADC12_A enable conversion ADC12ENC
//__delay_cycles(2000);
while( (ADC12CTL1&0x0001) == 1 );
value = ADC12MEM5;
return value;
}
and that's in the main function
while(1)
{
volatile unsigned short value_of_adc= ADC_READ();
__delay_cycles(2000000);
}
I'm not getting real value, actually I'm getting a ZERO!
I don't care if we change reference to VCC, but I just wanted it to be connected to the ADC module 2.5 v reference.
Where is my problem?
