diff options
Diffstat (limited to 'src/c/hardware/avr/adc')
-rw-r--r-- | src/c/hardware/avr/adc/u8AVRADCSetups.c | 42 | ||||
-rw-r--r-- | src/c/hardware/avr/adc/u8AVRReadADCs.c | 46 |
2 files changed, 88 insertions, 0 deletions
diff --git a/src/c/hardware/avr/adc/u8AVRADCSetups.c b/src/c/hardware/avr/adc/u8AVRADCSetups.c new file mode 100644 index 00000000..620f80fe --- /dev/null +++ b/src/c/hardware/avr/adc/u8AVRADCSetups.c @@ -0,0 +1,42 @@ +// Function to initialise ADC of AVR +// +// Calling Sequence +// AVRSetupADC(uint8 prescalar, uint8 adc_ref) +// +// Parameters +// prescalar: prescalar to be used for generating ADC clock (0-7) +// adc_ref : reference voltage to be used for ADC conversion +// 0 -> Voltage on VREF pin +// 1 -> Voltage on AVCC pin +// 2 -> Internal 2.56 reference voltage +// +// Description +// This function initialises ADc of AVR with given parameters. 'prescalar' is +// needed for deciding ADC clock. ADC clock should be between 50KHz and 200KHz +// and it given as (MCU clock/2^prescalar). Select appropriate prescalar depending +// on MCU clock. 'adc_ref' selects one of the available reference voltage sources +// available +// Examples +// AVRADCSetup(128,0) +// +// Authors +// Siddhesh Wani +// + +#include "AVRPeripheralADC.h" + + +uint8 u8AVRADCSetups(uint8 prescalar, uint8 adc_ref) +{ + /*Set the prescalar value*/ + ADCSRA |= (prescalar & 0x07); + + /*Set the adc reference voltage*/ + ADMUX |= ((adc_ref & 0x03) << 6); + + /*Enable ADC hardware. Set ADEN bit*/ + ADCSRA |= (1<<7); + + return 0; +} + diff --git a/src/c/hardware/avr/adc/u8AVRReadADCs.c b/src/c/hardware/avr/adc/u8AVRReadADCs.c new file mode 100644 index 00000000..71fe1363 --- /dev/null +++ b/src/c/hardware/avr/adc/u8AVRReadADCs.c @@ -0,0 +1,46 @@ +// Function to get voltage on analog pin on AVR +// +// Calling Sequence +// u8AVRReadADCs(channel) +// +// Parameters +// channel : Select which channel is to be read. Values from 0-7 select one +// of the pins ADC0-ADC7. For other possible channel values refer +// datasheet +// Returns-> +// result : Digital value for the voltage present on channel selected +// +// Description +// This function returns digital value for present on adc pins. 'channel' +// selects which of the ADC0-ADC7 is to be used for reading analog value. +// Apart from reading just ADC0-ADC7 other it can also read differential +// voltages between some pins. For channel values for those options, please +// refer datasheet. +// +// Examples +// adc_result = u8AVRReadADC(0) //Read ADC0 +// +// Authors +// Siddhesh Wani +// + + +#include "AVRPeripheralADC.h" + +uint16 u8AVRReadADCs(uint8 channel) +{ + /*Set ADC conversion channel*/ + ADMUX |= (channel & 0x1F); + + /*Start ADC conversion. Set 'ADSC' bit*/ + ADCSRA |= (1<<6); + + /*Wait for conversion to complete. Check 'ADIF' bit*/ + while(!(ADCSRA & (1<<4))); + + /*Clear ADIF flag*/ + ADCSRA |= (1<<4); + + /*ADC conversion result is stored in ADCH/L registers*/ + return (ADC); +} |