Content originally posted in LPCWare by Redbull68 on Wed May 28 05:31:42 MST 2014 Hi,
I try to use the on chip ADC but I have a problem with the result. I use the software control to start and stop acquisiton on AD0 pin where a generator is connected to have a stable voltage.
void HalAdcInit(void)
{
// Configure pin as ADC peripheral
IOCON_PIO0_30 |= 3; // channel AD0
IOCON_PIO0_30 &= 0xFF7F; // Pin as analog
PDRUNCFG_bit.ADC_PD = 0; // Enable Power on ADC
SYSAHBCLKCTRL_bit.ADC = 1; // Enable ADC clock
AD0CR_bit.CLKDIV = 3; // Divider (value + 1) for APB clock to have an ADC clock
// less than 9 MHz
// ADC clock = System clock / (CLKDIV + 1)
// 33177600 / 4
// 8294400 Hz
AD0CR_bit.SEL = 1;
AD0CR_bit.BURST = 0; // Conversion are software controlled
AD0CR_bit.START = 0; // A/D conversion stop
}/*END HalAdcInit*/
void HalAdcTest2(void)
{
UVAR_16 i;
UVAR_16 tab[400];
memset(tab, 0, sizeof(tab));
while (1)
{
for (i = 0; i < 400; i++)
{
AD0CR_bit.START = 1;
while (AD0DR0_bit.DONE != 1);
AD0CR_bit.START = 0;
tab = AD0DR0_bit.RESULT;
}
}
}
I do the initialisation and after only HalAdcTest2 function running. When i run the loop only 1 time, data in tab is good but if I launch continually the function and i stop in the fly, data in tab is not good( sequence of 0x003F and 0x03C1)
