Part Number: MSP430F5529
OK quick code fragment. I expect ADC12 to be busy on entering the TIMER B0 interrupt - but it isn't; so my guess is I've missed enabling something. So is it anything obvious? I'll go through the documentation carefully this weekend.
int main(void)
{
// Stop WDT
HWREGW( WDT_A_BASE | WDTCTL ) = WDTPW|WDTHOLD;
// stop interupts whilst we configure
__disable_interrupt();
// first disable ADC12
HWREGW( ADC12_A_BASE | ADC12CTL0 )&= ~ADC12ENC;
HWREGW( ADC12_A_BASE | ADC12CTL0 )&= ~ADC12ON;
// 4 ticks sample and hold.
// 0x80 = 1 - sample on SHi signal
// 0x40 - 2.5V ADC12_A ref gen volt
// 0x20 - Ref on
// 0x10 =0 - ADC12_A is off
// 0x08 =0 - overflow int disable
// 0x04 =0 - conversion time int disable
// 0x02 - enable conversion ????
// 0x01 - Start conversiom
HWREGW( ADC12_A_BASE | ADC12CTL0 ) =
ADC12SHT0_0 | ADC12MSC | ADC12REF2_5V | ADC12REFON ;
// ADC12CSTARTADDx = 0 (write starting at ADC12MEM0)
// ADC12SHP =0
// ADC12SHSx = 2 - Timer B0
// ADC12ISSH = 0 Not inverted
// ADC12DIVx = 0 (divide by 1)
// ADC12SSELx = 3 (SMCLK)
HWREGW( ADC12_A_BASE | ADC12CTL1 ) =
ADC12SHS_2 | ADC12SSEL_3 ;
// ADC12PDIV =0 (predivide 1)
// ADC12TCOFF =0 (oddly means temp sensor on)
// ADC12RES=2 (12bit)
// ADC12DF=0 (unsigned)
// ADC12SR=0 (200ksps sample rate)
// ADC12REFOUT=1 = Ref Output on
// ADC12REFBURST=1 only on during sample and convert
HWREGW( ADC12_A_BASE | ADC12CTL2 ) =
ADC12RES_2 | ADC12REFOUT | ADC12REFBURST;
// ADC12SREF2 = 1 Vref- user the external reference
// ADC12SFREG01 = 11 or 10 - user Vref+
HWREGB( ADC12_A_BASE | ADC12MCTL0 ) = ADC12SREF_7 | ADC12INCH_0;
HWREGB( ADC12_A_BASE | ADC12MCTL1 ) = ADC12SREF_7 | ADC12INCH_10;
HWREGB( ADC12_A_BASE | ADC12MCTL2 ) = ADC12EOS;
// enable ADC12
HWREGW( ADC12_A_BASE | ADC12CTL0 )|= ADC12ON;
HWREGW( ADC12_A_BASE | ADC12CTL0 )|= ADC12ENC;
__enable_interrupt();
// now all set for now just loop, with LED flashing
while(1) {
}
}
// TIMER B CC
__attribute__ ((interrupt(TIMER0_B0_VECTOR)))
void TIMER0_B0_ISR (void)
{
sprintf(print,"%i\0", HWREGW( ADC12_A_BASE | ADC12CTL1 )&ADC12BUSY);
}
The print buffer, is processed by a USCI_A1 interrupt and sent to the UART.
On the UART I just get "0" output - which given that its the first instruction in Timer B interrupter routine, and that is meant to trigger the ADC12, seems wrong.
Any ideas anyone? I'll keep digging.
