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| Rev | Author | Line No. | Line |
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| 2 | mjames | 1 | |
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| 5 | #include "ch.h" // needs for all ChibiOS programs |
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| 6 | #include "hal.h" // hardware abstraction layer header |
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| 7 | |||
| 8 | #include "useAdc.h" |
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| 9 | |||
| 10 | |||
| 11 | // Lets configure our ADC first |
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| 12 | |||
| 13 | |||
| 14 | // ADCConfig structure for stm32 MCUs is empty |
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| 15 | static ADCConfig adccfg = {}; |
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| 16 | |||
| 17 | // Create buffer to store ADC results. This is |
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| 18 | // one-dimensional interleaved array |
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| 19 | #define ADC_BUF_DEPTH 2 // depth of buffer |
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| 20 | #define ADC_CH_NUM 1 // number of used ADC channels |
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| 21 | static adcsample_t samples_buf[ADC_BUF_DEPTH * ADC_CH_NUM]; // results array |
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| 22 | |||
| 23 | static int done; |
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| 24 | void terminateAdc(ADCDriver *adcp, adcsample_t *buffer, size_t n) |
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| 25 | { |
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| 26 | done = true; |
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| 27 | adcStopConversionI(adcp); |
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| 28 | } |
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| 29 | |||
| 30 | // Fill ADCConversionGroup structure fields |
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| 31 | static ADCConversionGroup adccg = { |
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| 32 | // this 3 fields are common for all MCUs |
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| 33 | // set to TRUE if need circular buffer, set FALSE otherwise |
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| 34 | TRUE, |
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| 35 | // number of channels |
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| 36 | (uint16_t)(ADC_CH_NUM), |
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| 37 | // callback function, set to NULL for begin |
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| 38 | &terminateAdc, |
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| 39 | // error callback function |
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| 40 | NULL, |
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| 41 | // Resent fields are stm32 specific. They contain ADC control registers data. |
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| 42 | // Please, refer to ST manual RM0008.pdf to understand what we do. |
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| 43 | // CR1 register content, set to zero for begin |
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| 44 | 0, |
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| 45 | // CR2 register content, set to zero for begin |
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| 46 | ADC_CR2_EXTTRIG , |
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| 47 | // SMRP1 register content, set to zero for begin |
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| 48 | 0, |
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| 49 | // SMRP2 register content, set to zero for begin |
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| 50 | 0, |
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| 51 | // SQR1 register content. Set channel sequence length |
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| 52 | ADC_SQR1_NUM_CH(ADC_CH_NUM), |
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| 53 | // SQR2 register content, set to zero for begin |
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| 54 | 0, |
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| 55 | // SQR3 register content. We must select 2 channels |
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| 56 | // For example 2nd and 3rd channels. Refer to the |
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| 57 | // pinout of your MCU to select other pins you need. |
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| 58 | // On STM32-P103 board they connected to PA4 |
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| 59 | (4 | (0 << 5)), |
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| 60 | }; |
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| 61 | |||
| 62 | // Thats all with configuration |
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| 63 | |||
| 64 | void useAdc(void) |
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| 65 | { |
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| 66 | // Following 3 functions use previously created configuration |
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| 67 | // to initialize ADC block, start ADC block and start conversion. |
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| 68 | // &ADCD1 is pointer to ADC driver structure, defined in the depths of HAL. |
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| 69 | // Other arguments defined ourself earlier. |
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| 70 | adcStart(&ADCD1, &adccfg); |
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| 71 | } |
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| 72 | adcsample_t getAdc(uint8_t chan) |
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| 73 | { |
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| 74 | return(samples_buf[chan & 1]); |
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| 75 | } |
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| 76 | |||
| 77 | // samples into buffer |
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| 78 | void adcSample(void) |
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| 79 | { |
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| 80 | done = false; |
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| 81 | adcConvert(&ADCD1, &adccg, &samples_buf[0], ADC_BUF_DEPTH); |
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| 82 | while(!done) |
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| 83 | chThdSleep(10); |
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| 84 | } |
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| 85 |