Class similar to AnalogIn that uses burst mode to run continious background conversions so when the input is read, the last value can immediatly be returned. This slightly modified version allows NC pins.
Dependents: Pinscape_Controller
Fork of FastAnalogIn by
FastAnalogIn_LPC11UXX.cpp
- Committer:
- Sissors
- Date:
- 2014-11-04
- Revision:
- 10:afc3b84dbbd6
- Parent:
- 8:68082fdde730
File content as of revision 10:afc3b84dbbd6:
#ifdef TARGET_LPC11UXX #include "FastAnalogIn.h" static inline int div_round_up(int x, int y) { return (x + (y - 1)) / y; } #define LPC_IOCON0_BASE (LPC_IOCON_BASE) #define LPC_IOCON1_BASE (LPC_IOCON_BASE + 0x60) #define MAX_ADC_CLK 4500000 static const PinMap PinMap_ADC[] = { {P0_11, ADC0_0, 0x02}, {P0_12, ADC0_1, 0x02}, {P0_13, ADC0_2, 0x02}, {P0_14, ADC0_3, 0x02}, {P0_15, ADC0_4, 0x02}, {P0_16, ADC0_5, 0x01}, {P0_22, ADC0_6, 0x01}, {P0_23, ADC0_7, 0x01}, {NC , NC , 0 } }; static int channel_usage[8] = {0,0,0,0,0,0,0,0}; FastAnalogIn::FastAnalogIn(PinName pin, bool enabled) { ADCnumber = (ADCName)pinmap_peripheral(pin, PinMap_ADC); if (ADCnumber == (uint32_t)NC) error("ADC pin mapping failed"); datareg = (uint32_t*) (&LPC_ADC->DR0 + ADCnumber); // Power up ADC LPC_SYSCON->PDRUNCFG &= ~ (1 << 4); LPC_SYSCON->SYSAHBCLKCTRL |= ((uint32_t)1 << 13); uint32_t pin_number = (uint32_t)pin; __IO uint32_t *reg = (pin_number < 32) ? (__IO uint32_t*)(LPC_IOCON0_BASE + 4 * pin_number) : (__IO uint32_t*)(LPC_IOCON1_BASE + 4 * (pin_number - 32)); // set pin to ADC mode *reg &= ~(1 << 7); // set ADMODE = 0 (analog mode) uint32_t clkdiv = div_round_up(SystemCoreClock, MAX_ADC_CLK) - 1; LPC_ADC->CR = (LPC_ADC->CR & 0xFF) // keep current channels | (clkdiv << 8) // max of 4.5MHz | (1 << 16) // BURST = 1, hardware controlled | ( 0 << 17 ); // CLKS = 0, we stick to 10 bit mode pinmap_pinout(pin, PinMap_ADC); //Enable channel running = false; enable(enabled); } void FastAnalogIn::enable(bool enabled) { //If currently not running if (!running) { if (enabled) { //Enable the ADC channel channel_usage[ADCnumber]++; LPC_ADC->CR |= (1<<ADCnumber); running = true; } else disable(); } } void FastAnalogIn::disable( void ) { //If currently running if (running) { channel_usage[ADCnumber]--; if (channel_usage[ADCnumber]==0) LPC_ADC->CR &= ~(1<<ADCnumber); } running = false; } unsigned short FastAnalogIn::read_u16( void ) { unsigned int retval; //If object is enabled return current value of datareg if (running) retval = *datareg; //If it isn't running, enable it and wait until new value is written to datareg else { //Force a read to clear done bit, enable the ADC channel retval = *datareg; enable(); //Wait until it is converted while(1) { retval = *datareg; if ((retval>>31) == 1) break; } //Disable again disable(); } //Do same thing as standard mbed lib, unused bit 0-3, replicate 4-7 in it retval &= ~0xFFFF003F; retval |= (retval >> 6) & 0x003F; return retval; } #endif //defined TARGET_LPC11UXX