defines changed from TARGET_LPC1768 to TARGET_LPC176X to support LPC1769 target
Fork of FastAnalogIn by
Diff: FastAnalogIn_LPC408X.cpp
- Revision:
- 4:cd84739f7640
- Child:
- 5:55274430c8df
diff -r a9b753c25073 -r cd84739f7640 FastAnalogIn_LPC408X.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/FastAnalogIn_LPC408X.cpp Sun Apr 20 16:23:19 2014 +0000 @@ -0,0 +1,128 @@ +#ifdef TARGET_LPC408X + +#include "FastAnalogIn.h" + +static inline int div_round_up(int x, int y) +{ + return (x + (y - 1)) / y; +} + +static const PinMap PinMap_ADC[] = { + {P0_23, ADC0_0, 0x01}, + {P0_24, ADC0_1, 0x01}, + {P0_25, ADC0_2, 0x01}, + {P0_26, ADC0_3, 0x01}, + {P1_30, ADC0_4, 0x03}, + {P1_31, ADC0_5, 0x03}, + {P0_12, ADC0_6, 0x03}, + {P0_13, ADC0_7, 0x03}, + {NC , NC , 0 } +}; + +int FastAnalogIn::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"); + //printf("ADC_ID=%u\n",ADCnumber); + datareg = (uint32_t*) (&LPC_ADC->DR[ADCnumber]); + + wait_us(1000); // we need either the debug printf above or a wait before we try to initialize the ADC + + // ensure power is turned on + LPC_SC->PCONP |= (1 << 12); + + uint32_t PCLK = PeripheralClock; + + // calculate minimum clock divider + // clkdiv = divider - 1 + uint32_t MAX_ADC_CLK = 12400000; + uint32_t clkdiv = div_round_up(PCLK, MAX_ADC_CLK) - 1; + // Set the clkdiv + LPC_ADC->CR &= ~(255<<8); + LPC_ADC->CR |= clkdiv<<8; + + //Enable ADC: + LPC_ADC->CR |= 1<<21; + + //Enable burstmode, set start as zero + LPC_ADC->CR |= 1<<16; + LPC_ADC->CR &= ~(7<<24); + + // must enable analog mode (ADMODE = 0) ... ??? just copied from official LPC408X analogin_api.c + __IO uint32_t *reg = (__IO uint32_t*) (LPC_IOCON_BASE + 4 * pin); + *reg &= ~(1 << 7); + + //Map pins + 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 ) +{ + volatile 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) { + wait_us(1); + retval = *datareg; + if ((retval>>31) == 1) + break; + } + //Do a second conversion since first one always fails for some reason + while(1) { + wait_us(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 &= ~0xFFFF000F; + retval |= (retval >> 8) & 0x000F; + return retval; + +} +#endif //defined TARGET_LPC408X