diff options
Diffstat (limited to 'openpicc/application/adc.c')
| -rw-r--r-- | openpicc/application/adc.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/openpicc/application/adc.c b/openpicc/application/adc.c new file mode 100644 index 0000000..4aa900e --- /dev/null +++ b/openpicc/application/adc.c @@ -0,0 +1,45 @@ +/* AT91 ADC for OpenPICC + * (C) 2007 Henryk Plötz <henryk@ploetzli.ch> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + + +#include "openpicc.h" +#include "board.h" + +#include <sys/types.h> +#include <lib_AT91SAM7.h> + +static AT91S_ADC* adc = AT91C_BASE_ADC; + +int adc_get_field_strength(void) +{ + adc->ADC_CR = AT91C_ADC_START; + while( (adc->ADC_SR & AT91C_ADC_EOC4)==0) ; + return adc->ADC_CDR4; +} + +void adc_init(void) +{ + // PRESCAL = 4 -> ADC clock = MCLK / 10 = 4.8 MHz (max is 5 MHz at 10 bit) + // Start time <20 us -> STARTUP=11 + // Track and hold time >600 ns -> SHTIM=2 + adc->ADC_MR = AT91C_ADC_TRGEN_DIS | AT91C_ADC_LOWRES_10_BIT | + AT91C_ADC_SLEEP_MODE | (4 << 8) | (11 << 16) | (2 << 24); + adc->ADC_IDR = 0xfffff; + adc->ADC_CHER = OPENPICC_ADC_FIELD_STRENGTH; +} |