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Optionally measure ADC2 along with temperature

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This commit is contained in:
dak664 2010-02-11 20:49:31 +00:00
parent e9d760bf9e
commit cc47c556e7
1 changed files with 21 additions and 2 deletions
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19
platform/avr-ravenlcd/temp.c
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@ -147,12 +147,18 @@ temp_deinit(void)
*
* After the raw adc value is stored, it will be used to lookup a degree conversion
* based on the tables for F or C.
* Optionally, EXT_SUPL_SIG is also read on channel 2 and stored in the global
* ADC2_reading for subsequent transfer to the 1284p web server.
*
* \param unit Used to determine what unit needs to be appended with the value.
*
* \return EOF This is an uninitialized adc error.
* \retval temp The newly converted value in degrees F or C.
*/
#if MEASURE_ADC2
uint16_t ADC2_reading;
#endif
int16_t
temp_get(temp_unit_t unit)
{
@ -173,6 +179,19 @@ temp_get(temp_unit_t unit)
while ((res = adc_result_get(ADC_ADJ_RIGHT)) == EOF ){
;
}
#if MEASURE_ADC2
/* Measure external voltage supply, routed to ADC2 through a 470K/100K divider*/
/* AVCC is 3.3 volts if using external supply, else Vbat which will be lower */
/* Convert result to millivolts assuming AVCC is 3.3 volts, on battery it will be lower! */
adc_init(ADC_CHAN_ADC2, ADC_TRIG_FREE_RUN, ADC_REF_AVCC, ADC_PS_128);
adc_conversion_start();
while ((ADC2_reading = adc_result_get(ADC_ADJ_RIGHT)) == EOF ){
;
}
ADC2_reading = (ADC2_reading*((470+100)*3300UL))/(100*1024UL);
#endif
adc_deinit();
/* Re-init the adc for buttons. */
key_init();