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88 lines
2.1 KiB
88 lines
2.1 KiB
/* |
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This program is free software: you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation, either version 3 of the License, or |
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(at your option) any later version. |
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This program is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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GNU General Public License for more details. |
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You should have received a copy of the GNU General Public License |
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along with this program. If not, see <http://www.gnu.org/licenses/>. |
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*/ |
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/* |
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analog capture for IOMCU. This uses direct register access to avoid |
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using up a DMA channel and to minimise latency. We capture a single |
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sample at a time |
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*/ |
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#include "ch.h" |
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#include "hal.h" |
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#include "analog.h" |
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#if HAL_USE_ADC != TRUE |
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#error "HAL_USE_ADC must be set" |
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#endif |
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/* |
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initialise ADC capture |
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*/ |
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void adc_init(void) |
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{ |
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adc_lld_init(); |
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rccEnableADC1(true); |
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/* set channels 4 and 5 for 28.5us sample time */ |
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ADC1->SMPR2 = ADC_SMPR2_SMP_AN4(ADC_SAMPLE_28P5) | ADC_SMPR2_SMP_AN5(ADC_SAMPLE_28P5); |
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/* capture a single sample at a time */ |
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ADC1->SQR1 = 0; |
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ADC1->SQR2 = 0; |
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} |
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/* |
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capture one sample on a channel |
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*/ |
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static uint16_t adc_sample_channel(uint32_t channel) |
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{ |
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// clear EOC |
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ADC1->SR = 0; |
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/* capture one sample */ |
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ADC1->SQR3 = channel; |
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ADC1->CR2 |= ADC_CR2_ADON; |
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/* wait for the conversion to complete */ |
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uint32_t counter = 16; |
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while (!(ADC1->SR & ADC_SR_EOC)) { |
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if (--counter == 0) { |
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// ensure EOC is clear |
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ADC1->SR = 0; |
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return 0xffff; |
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} |
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} |
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// return sample (this also clears EOC flag) |
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return ADC1->DR; |
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} |
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/* |
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capture VSERVO in mV |
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*/ |
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uint16_t adc_sample_vservo(void) |
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{ |
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const uint32_t channel = ADC_SQR3_SQ1_N(ADC_CHANNEL_IN4); |
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return adc_sample_channel(channel) * 9900 / 4096; |
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} |
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/* |
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capture VRSSI in mV |
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*/ |
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uint16_t adc_sample_vrssi(void) |
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{ |
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const uint32_t channel = ADC_SQR3_SQ1_N(ADC_CHANNEL_IN5); |
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return adc_sample_channel(channel) * 9900 / 4096; |
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}
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