wrapped samd21 adc/dma implementation in an ugly class

Author: maxlem

src/SimpleFOC.h

@@ -109,6 +109,7 @@ void loop() {
 #include "drivers/StepperDriver4PWM.h"
 #include "drivers/StepperDriver2PWM.h"
 #include "current_sense/InlineCurrentSense.h"
+#include "current_sense/LowSideCurrentSense.h"
 #include "communication/Commander.h"
 #include "communication/StepDirListener.h"
 

src/current_sense/LowSideCurrentSense.cpp

@@ -5,7 +5,9 @@
 //  - phA   - A phase adc pin
 //  - phB   - B phase adc pin
 //  - phC   - C phase adc pin (optional)
-LowSideCurrentSense::LowSideCurrentSense(float _shunt_resistor, float _gain, int _pinA, int _pinB, int _pinC){
+LowSideCurrentSense::LowSideCurrentSense(float _shunt_resistor, float _gain, int _pinA, int _pinB, int _pinC): 
+adc(_pinA, _pinB, _pinC)
+{
     pinA = _pinA;
     pinB = _pinB;
     pinC = _pinC;
@@ -21,9 +23,7 @@ LowSideCurrentSense::LowSideCurrentSense(float _shunt_resistor, float _gain, int
 
 // Inline sensor init function
 void LowSideCurrentSense::init(){
-    // configure ADC variables
-    _configure3PinsDMA(pinA,pinB,pinC);
-    _start3PinsDMA(); //start next acuisition
+    adc.init();
     // calibrate zero offsets
     // calibrateOffsets();
 }
@@ -54,8 +54,9 @@ PhaseCurrent_s LowSideCurrentSense::getPhaseCurrents(){
     // current.a = (_readADCVoltage(pinA) - offset_ia)*gain_a;// amps
     // current.b = (_readADCVoltage(pinB) - offset_ib)*gain_b;// amps
     // current.c = (!_isset(pinC)) ? 0 : (_readADCVoltage(pinC) - offset_ic)*gain_c; // amps
-    _read3PinsDMA(pinA, pinB, pinC, current.a, current.b, current.c);
-    _start3PinsDMA();
+    
+    adc._read3PinsDMA(pinA, pinB, pinC, current.a, current.b, current.c);
+    adc._start3PinsDMA();
 
     return current;
 }

src/current_sense/LowSideCurrentSense.h

@@ -6,6 +6,7 @@
 #include "../common/time_utils.h"
 #include "../common/base_classes/CurrentSense.h"
 #include "hardware_api.h"
+#include "hardware_specific/samd21_mcu.h"
 
 class LowSideCurrentSense: public CurrentSense{
   public:
@@ -52,6 +53,8 @@ class LowSideCurrentSense: public CurrentSense{
     double offset_ib; //!< zero current B voltage value (center of the adc reading)
     double offset_ic; //!< zero current C voltage value (center of the adc reading)
 
+    SAMDCurrentSensceADC adc;
+
 };
 
 #endif

src/current_sense/hardware_specific/samd21_mcu.cpp

@@ -1,35 +1,57 @@
 
-#include "../hardware_api.h"
+#include "samd21_mcu.h"
 
-// this code was pulled from Paul Gould's git https://github.com/gouldpa/FOC-Arduino-Brushless
-static uint32_t ADC_OneBeforeFirstPin; // hack to discard first noisy readout
-static uint32_t ADC_FirstPin; // PA04
-static uint32_t ADC_LastPin;  // PA06
-static uint32_t BufferSize = 0;
 
-uint16_t adcBuffer[20];
+void adc_stop_with_DMA(void);
+void adc_start_with_DMA(void);
 
+/**
+ * @brief  ADC sync wait 
+ * @retval void
+ */
+static __inline__ void ADCsync() __attribute__((always_inline, unused));
+static void   ADCsync() {
+  while (ADC->STATUS.bit.SYNCBUSY == 1); //Just wait till the ADC is free
+}
+
+//  ADC DMA sequential free running (6) with Interrupts /////////////////
+
+typedef struct {
+  uint16_t btctrl;
+  uint16_t btcnt;
+  uint32_t srcaddr;
+  uint32_t dstaddr;
+  uint32_t descaddr;
+} dmacdescriptor ;
+volatile dmacdescriptor wrb[12] __attribute__ ((aligned (16)));
+dmacdescriptor descriptor_section[12] __attribute__ ((aligned (16)));
+dmacdescriptor descriptor __attribute__ ((aligned (16)));
+DmacDescriptor *desc; // DMA descriptor address (so we can change contents)
 
-static uint32_t ADC_pinA = A4;
-static uint32_t ADC_pinB = A5;
-static uint32_t ADC_pinC = 8;
 
 
-#define _ADC_VOLTAGE 3.3 // we use ADC_REFCTRL_REFSEL_INTVCC1_Val
-#define _ADC_RESOLUTION (1 << 12)
-#define ADC_CONV_ ( _ADC_VOLTAGE / _ADC_RESOLUTION )
+SAMDCurrentSensceADC::SAMDCurrentSensceADC(int pinA, int pinB, int pinC, float arefaVoltage, uint32_t adcBits) 
+: _ADC_VOLTAGE(arefaVoltage), _ADC_RESOLUTION(1 << adcBits)
+{
+  ADC_CONV_ = ( _ADC_VOLTAGE / _ADC_RESOLUTION );
+  this->pinA = pinA;
+  this->pinB = pinB;
+  this->pinC = pinC;
+}
+
+void SAMDCurrentSensceADC::init()
+{
+  _configure3PinsDMA();
+  _start3PinsDMA(); //s
+}
 
-void adc_dma(void *rxdata, size_t hwords);
-void adc_init();
-void adc_start_with_DMA();
-void dma_init();
 
-void _start3PinsDMA()
+void SAMDCurrentSensceADC::_start3PinsDMA()
 {
   adc_dma(adcBuffer + ADC_OneBeforeFirstPin, BufferSize);
   adc_start_with_DMA();
 }
-void _read3PinsDMA(const int pinA,const int pinB,const int pinC, float & a, float & b, float & c)
+void SAMDCurrentSensceADC::_read3PinsDMA(const int pinA,const int pinB,const int pinC, float & a, float & b, float & c)
 {
   while(ADC->CTRLA.bit.ENABLE) ;
   uint32_t adcA = g_APinDescription[pinA].ulADCChannelNumber;
@@ -44,7 +66,7 @@ void _read3PinsDMA(const int pinA,const int pinB,const int pinC, float & a, floa
 }
 
 // function reading an ADC value and returning the read voltage
-void _configure3PinsDMA(const int pinA,const int pinB,const int pinC){
+void SAMDCurrentSensceADC::_configure3PinsDMA(){
 
   uint32_t adcA = g_APinDescription[pinA].ulADCChannelNumber;
   uint32_t adcB = g_APinDescription[pinB].ulADCChannelNumber;
@@ -65,52 +87,24 @@ void _configure3PinsDMA(const int pinA,const int pinB,const int pinC){
   ADC_OneBeforeFirstPin = ADC_FirstPin - 1; //hack to discard noisy first readout
   BufferSize = ADC_LastPin - ADC_OneBeforeFirstPin + 1;
 
-  ADC_pinA = pinA;
-  ADC_pinB = pinB;
-  ADC_pinC = pinC;
-
   // ADC and DMA
   adc_init();
   dma_init();
 }
 
 
 
-//  ADC DMA sequential free running (6) with Interrupts /////////////////
-
-typedef struct {
-  uint16_t btctrl;
-  uint16_t btcnt;
-  uint32_t srcaddr;
-  uint32_t dstaddr;
-  uint32_t descaddr;
-} dmacdescriptor ;
-volatile dmacdescriptor wrb[12] __attribute__ ((aligned (16)));
-dmacdescriptor descriptor_section[12] __attribute__ ((aligned (16)));
-dmacdescriptor descriptor __attribute__ ((aligned (16)));
-DmacDescriptor *desc; // DMA descriptor address (so we can change contents)
-
-static uint32_t ADC_DMA_chnl = 3;  // DMA channel
 
 
-/**
- * @brief  ADC sync wait 
- * @retval void
- */
-static __inline__ void ADCsync() __attribute__((always_inline, unused));
-static void   ADCsync() {
-  while (ADC->STATUS.bit.SYNCBUSY == 1); //Just wait till the ADC is free
-}
-
 /**
  * @brief  Initialize ADC
  * @retval void
  */
-void adc_init(){
+void SAMDCurrentSensceADC::adc_init(){
 
-  auto a = analogRead(ADC_pinA);  // do some pin init  pinPeripheral() 
-  auto b = analogRead(ADC_pinB);  // do some pin init  pinPeripheral() 
-  auto c = analogRead(ADC_pinC);  // do some pin init  pinPeripheral() 
+  analogRead(pinA);  // do some pin init  pinPeripheral() 
+  analogRead(pinB);  // do some pin init  pinPeripheral() 
+  analogRead(pinC);  // do some pin init  pinPeripheral() 
 
   ADC->CTRLA.bit.ENABLE = 0x00; // Disable ADC
   ADCsync();
@@ -121,62 +115,55 @@ void adc_init(){
   // ADC->REFCTRL.bit.REFSEL = ADC_REFCTRL_REFSEL_INTVCC0;
   ADCsync();  //  ref 31.6.16
 
-  a = analogRead(ADC_pinA);  // do some pin init  pinPeripheral() 
-  b = analogRead(ADC_pinB);  // do some pin init  pinPeripheral() 
-  c = analogRead(ADC_pinC);  // do some pin init  pinPeripheral() 
-  SerialUSB.println("--------------");
-  SerialUSB.println(a);
-  SerialUSB.println(b);
-  SerialUSB.println(c);
-  SerialUSB.println("--------------");
-/*
-Bits 19:16 – INPUTSCAN[3:0]: Number of Input Channels Included in Scan
-This register gives the number of input sources included in the pin scan. The number of input sources included is
-INPUTSCAN + 1. The input channels included are in the range from MUXPOS + INPUTOFFSET to MUXPOS +
-INPUTOFFSET + INPUTSCAN.
-The range of the scan mode must not exceed the number of input channels available on the device.
-Bits 4:0 – MUXPOS[4:0]: Positive Mux Input Selection
-These bits define the Mux selection for the positive ADC input. Table 32-14 shows the possible input selections. If
-the internal bandgap voltage or temperature sensor input channel is selected, then the Sampling Time Length bit
-group in the SamplingControl register must be written.
-Table 32-14. Positive Mux Input Selection
-MUXPOS[4:0] Group configuration Description
-0x00 PIN0 ADC AIN0 pin
-0x01 PIN1 ADC AIN1 pin
-0x02 PIN2 ADC AIN2 pin
-0x03 PIN3 ADC AIN3 pin
-0x04 PIN4 ADC AIN4 pin
-0x05 PIN5 ADC AIN5 pin
-0x06 PIN6 ADC AIN6 pin
-0x07 PIN7 ADC AIN7 pin
-0x08 PIN8 ADC AIN8 pin
-0x09 PIN9 ADC AIN9 pin
-0x0A PIN10 ADC AIN10 pin
-0x0B PIN11 ADC AIN11 pin
-0x0C PIN12 ADC AIN12 pin
-0x0D PIN13 ADC AIN13 pin
-0x0E PIN14 ADC AIN14 pin
-0x0F PIN15 ADC AIN15 pin
-0x10 PIN16 ADC AIN16 pin
-0x11 PIN17 ADC AIN17 pin
-0x12 PIN18 ADC AIN18 pin
-0x13 PIN19 ADC AIN19 pin
-0x14-0x17 Reserved
-0x18 TEMP Temperature reference
-0x19 BANDGAP Bandgap voltage
-0x1A SCALEDCOREVCC 1/4 scaled core supply
-0x1B SCALEDIOVCC 1/4 scaled I/O supply
-0x1C DAC DAC output
-0x1D-0x1F Reserved
-*/
+  /*
+  Bits 19:16 – INPUTSCAN[3:0]: Number of Input Channels Included in Scan
+  This register gives the number of input sources included in the pin scan. The number of input sources included is
+  INPUTSCAN + 1. The input channels included are in the range from MUXPOS + INPUTOFFSET to MUXPOS +
+  INPUTOFFSET + INPUTSCAN.
+  The range of the scan mode must not exceed the number of input channels available on the device.
+  Bits 4:0 – MUXPOS[4:0]: Positive Mux Input Selection
+  These bits define the Mux selection for the positive ADC input. Table 32-14 shows the possible input selections. If
+  the internal bandgap voltage or temperature sensor input channel is selected, then the Sampling Time Length bit
+  group in the SamplingControl register must be written.
+  Table 32-14. Positive Mux Input Selection
+  MUXPOS[4:0] Group configuration Description
+  0x00 PIN0 ADC AIN0 pin
+  0x01 PIN1 ADC AIN1 pin
+  0x02 PIN2 ADC AIN2 pin
+  0x03 PIN3 ADC AIN3 pin
+  0x04 PIN4 ADC AIN4 pin
+  0x05 PIN5 ADC AIN5 pin
+  0x06 PIN6 ADC AIN6 pin
+  0x07 PIN7 ADC AIN7 pin
+  0x08 PIN8 ADC AIN8 pin
+  0x09 PIN9 ADC AIN9 pin
+  0x0A PIN10 ADC AIN10 pin
+  0x0B PIN11 ADC AIN11 pin
+  0x0C PIN12 ADC AIN12 pin
+  0x0D PIN13 ADC AIN13 pin
+  0x0E PIN14 ADC AIN14 pin
+  0x0F PIN15 ADC AIN15 pin
+  0x10 PIN16 ADC AIN16 pin
+  0x11 PIN17 ADC AIN17 pin
+  0x12 PIN18 ADC AIN18 pin
+  0x13 PIN19 ADC AIN19 pin
+  0x14-0x17 Reserved
+  0x18 TEMP Temperature reference
+  0x19 BANDGAP Bandgap voltage
+  0x1A SCALEDCOREVCC 1/4 scaled core supply
+  0x1B SCALEDIOVCC 1/4 scaled I/O supply
+  0x1C DAC DAC output
+  0x1D-0x1F Reserved
+  */
   ADC->INPUTCTRL.bit.MUXPOS = ADC_OneBeforeFirstPin;
   ADCsync();
   ADC->INPUTCTRL.bit.INPUTSCAN = ADC_LastPin; // so the adc will scan from AIN[1] to AIN[ADC_Number+1] 
   ADCsync();
   ADC->INPUTCTRL.bit.INPUTOFFSET = 0; //input scan cursor
   ADCsync();
   ADC->AVGCTRL.reg = 0x00 ;  //no averaging
-  ADC->SAMPCTRL.reg = 0x05;  ; //sample length in 1/2 CLK_ADC cycles
+  ADC->SAMPCTRL.reg = 0x05;  ; //sample length in 1/2 CLK_ADC cycles, see GCLK_ADC and ADC_CTRLB_PRESCALER_DIV16
+  // according to the specsheet: f_GCLK_ADC ADC input clock frequency 48 MHz, so same as fCPU
   ADCsync();
   ADC->CTRLB.reg = ADC_CTRLB_PRESCALER_DIV16 | ADC_CTRLB_FREERUN | ADC_CTRLB_RESSEL_12BIT;
   ADCsync();
@@ -187,7 +174,7 @@ MUXPOS[4:0] Group configuration Description
  * @brief  dma_init
  * @retval void
  */
-void dma_init() {
+void SAMDCurrentSensceADC::dma_init() {
   // probably on by default
   PM->AHBMASK.reg |= PM_AHBMASK_DMAC ;
   PM->APBBMASK.reg |= PM_APBBMASK_DMAC ;
@@ -201,15 +188,15 @@ void dma_init() {
  * @brief  adc_dma 
  * @retval void
  */
-void adc_dma(void *rxdata,  size_t hwords) {
+void SAMDCurrentSensceADC::adc_dma(void *rxdata,  size_t hwords) {
   uint32_t temp_CHCTRLB_reg;
 
   DMAC->CHID.reg = DMAC_CHID_ID(ADC_DMA_chnl);
   DMAC->CHCTRLA.reg &= ~DMAC_CHCTRLA_ENABLE;
   DMAC->CHCTRLA.reg = DMAC_CHCTRLA_SWRST;
   DMAC->SWTRIGCTRL.reg &= (uint32_t)(~(1 << ADC_DMA_chnl));
   temp_CHCTRLB_reg = DMAC_CHCTRLB_LVL(0) |
-DMAC_CHCTRLB_TRIGSRC(ADC_DMAC_ID_RESRDY) | DMAC_CHCTRLB_TRIGACT_BEAT;
+  DMAC_CHCTRLB_TRIGSRC(ADC_DMAC_ID_RESRDY) | DMAC_CHCTRLB_TRIGACT_BEAT;
   DMAC->CHCTRLB.reg = temp_CHCTRLB_reg;
   DMAC->CHINTENSET.reg = DMAC_CHINTENSET_MASK ; // enable all 3 interrupts
   descriptor.descaddr = 0;
@@ -224,6 +211,9 @@ DMAC_CHCTRLB_TRIGSRC(ADC_DMAC_ID_RESRDY) | DMAC_CHCTRLB_TRIGACT_BEAT;
   DMAC->CHCTRLA.reg |= DMAC_CHCTRLA_ENABLE;
 }
 
+
+
+
 /**
  * @brief  adc_stop_with_DMA
  * @retval void
@@ -241,16 +231,12 @@ void adc_stop_with_DMA(void)
 void adc_start_with_DMA(void)
 {
   // SerialUSB.println("strating DMA...");
-
-
-  ADC->INPUTCTRL.bit.MUXPOS = ADC_OneBeforeFirstPin;
-  ADC->INPUTCTRL.bit.INPUTSCAN = ADC_LastPin;
+  // ADC->INPUTCTRL.bit.MUXPOS = ADC_OneBeforeFirstPin;
+  // ADC->INPUTCTRL.bit.INPUTSCAN = ADC_LastPin;
   ADC->INPUTCTRL.bit.INPUTOFFSET = 0;
   ADC->SWTRIG.bit.FLUSH = 1;
   ADC->CTRLA.bit.ENABLE = 0x01; 
 }
-
-
 /**
  * @brief  DMAC_Handler
  * @retval void
@@ -263,4 +249,4 @@ void DMAC_Handler() {
   DMAC->CHINTFLAG.reg = DMAC_CHINTENCLR_TCMPL; // clear
   DMAC->CHINTFLAG.reg = DMAC_CHINTENCLR_TERR;
   DMAC->CHINTFLAG.reg = DMAC_CHINTENCLR_SUSP;
-}
+}