215 lines
6.4 KiB
C++
215 lines
6.4 KiB
C++
// ADS1256 header file
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/*
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Name: ADS1256.h
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Created: 2022/07/14
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Author: Curious Scientist
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Editor: Notepad++
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Comment: Visit https://curiousscientist.tech/blog/ADS1256-custom-library
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Special thanks to
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Abraão Queiroz for spending time on the code and suggesting corrections for ESP32 microcontrollers
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Benjamin Pelletier for pointing out and fixing an issue around the handling of the DRDY signal
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*/
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#ifndef _ADS1256_h
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#define _ADS1256_h
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#include <SPI.h>
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#include <Arduino.h>
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// SPI Frequency
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#define SPI_FREQ 1920000
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// Differential inputs
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#define DIFF_0_1 0b00000001 // A0 + A1 as differential input
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#define DIFF_2_3 0b00100011 // A2 + A3 as differential input
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#define DIFF_4_5 0b01000101 // A4 + A5 as differential input
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#define DIFF_6_7 0b01100111 // A6 + A7 as differential input
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// Single-ended inputs
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#define SING_0 0b00001111 // A0 + GND (common) as single-ended input
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#define SING_1 0b00011111 // A1 + GND (common) as single-ended input
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#define SING_2 0b00101111 // A2 + GND (common) as single-ended input
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#define SING_3 0b00111111 // A3 + GND (common) as single-ended input
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#define SING_4 0b01001111 // A4 + GND (common) as single-ended input
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#define SING_5 0b01011111 // A5 + GND (common) as single-ended input
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#define SING_6 0b01101111 // A6 + GND (common) as single-ended input
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#define SING_7 0b01111111 // A7 + GND (common) as single-ended input
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// PGA settings //Input voltage range
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#define PGA_1 0b00000000 // ± 5 V
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#define PGA_2 0b00000001 // ± 2.5 V
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#define PGA_4 0b00000010 // ± 1.25 V
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#define PGA_8 0b00000011 // ± 625 mV
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#define PGA_16 0b00000100 // ± 312.5 mV
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#define PGA_32 0b00000101 //+ 156.25 mV
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#define PGA_64 0b00000110 // ± 78.125 mV
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// Datarate //DEC
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#define DRATE_30000SPS 0b11110000 // 240
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#define DRATE_15000SPS 0b11100000 // 224
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#define DRATE_7500SPS 0b11010000 // 208
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#define DRATE_3750SPS 0b11000000 // 192
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#define DRATE_2000SPS 0b10110000 // 176
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#define DRATE_1000SPS 0b10100001 // 161
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#define DRATE_500SPS 0b10010010 // 146
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#define DRATE_100SPS 0b10000010 // 130
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#define DRATE_60SPS 0b01110010 // 114
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#define DRATE_50SPS 0b01100011 // 99
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#define DRATE_30SPS 0b01010011 // 83
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#define DRATE_25SPS 0b01000011 // 67
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#define DRATE_15SPS 0b00110011 // 51
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#define DRATE_10SPS 0b00100011 // 35
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#define DRATE_5SPS 0b00010011 // 19
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#define DRATE_2SPS 0b00000011 // 3
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// Status register
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#define BITORDER_MSB 0
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#define BITORDER_LSB 1
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#define ACAL_DISABLED 0
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#define ACAL_ENABLED 1
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#define BUFFER_DISABLED 0
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#define BUFFER_ENABLED 1
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// Register addresses
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#define STATUS_REG 0x00
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#define MUX_REG 0x01
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#define ADCON_REG 0x02
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#define DRATE_REG 0x03
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#define IO_REG 0x04
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#define OFC0_REG 0x05
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#define OFC1_REG 0x06
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#define OFC2_REG 0x07
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#define FSC0_REG 0x08
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#define FSC1_REG 0x09
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#define FSC2_REG 0x0A
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// Command definitions
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#define WAKEUP 0b00000000
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#define RDATA 0b00000001
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#define RDATAC 0b00000011
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#define SDATAC 0b00001111
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#define RREG 0b00010000
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#define WREG 0b01010000
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#define SELFCAL 0b11110000
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#define SELFOCAL 0b11110001
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#define SELFGCAL 0b11110010
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#define SYSOCAL 0b11110011
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#define SYSGCAL 0b11110100
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#define SYNC 0b11111100
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#define STANDBY 0b11111101
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#define RESET 0b11111110
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//----------------------------------------------------------------
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class ADS1256
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{
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public:
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static constexpr int8_t PIN_UNUSED = -1;
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// Constructor
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ADS1256(const int8_t DRDY_pin, const int8_t RESET_pin, const int8_t SYNC_pin, const int8_t CS_pin, float VREF, SPIClass *spi = &SPI);
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~ADS1256()
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{
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vSemaphoreDelete(m_drdyHigh);
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vSemaphoreDelete(m_drdyLow);
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}
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// Initializing function
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void InitializeADC();
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// ADS1256(int drate, int pga, int byteOrder, bool bufen);
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// Read a register
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long readRegister(uint8_t registerAddress);
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// Write a register
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void writeRegister(uint8_t registerAddress, uint8_t registerValueToWrite);
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// Individual methods
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void setDRATE(uint8_t drate);
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void setPGA(uint8_t pga);
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uint8_t getPGA();
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void setMUX(uint8_t mux);
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void setByteOrder(uint8_t byteOrder);
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uint8_t getByteOrder();
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void setBuffer(uint8_t bufen);
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uint8_t getBuffer();
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void setAutoCal(uint8_t acal);
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uint8_t getAutoCal();
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void setGPIO(uint8_t dir0, uint8_t dir1, uint8_t dir2, uint8_t dir3);
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void writeGPIO(uint8_t dir0value, uint8_t dir1value, uint8_t dir2value, uint8_t dir3value);
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uint8_t readGPIO(uint8_t gpioPin);
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void setCLKOUT(uint8_t clkout);
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void setSDCS(uint8_t sdcs);
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void sendDirectCommand(uint8_t directCommand);
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// Get a single conversion
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long readSingle();
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// Single input continuous reading
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long readSingleContinuous();
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// Cycling through the single-ended inputs
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long cycleSingle(); // Ax + COM
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// Cycling through the differential inputs
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long cycleDifferential(); // Ax + Ay
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// Converts the reading into a voltage value
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float convertToVoltage(int32_t rawData);
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// Stop AD
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void stopConversion();
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// functions for callback
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inline uint8_t getDRDYpin()
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{
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return m_DRDY_pin;
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}
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SemaphoreHandle_t getDRDYsemaphoreHigh()
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{
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return m_drdyHigh;
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}
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SemaphoreHandle_t getDRDYsemaphoreLow()
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{
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return m_drdyLow;
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}
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private:
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SPIClass *_spi; // Pointer to an SPIClass object
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void waitForLowDRDY(); // Block until DRDY is low
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void waitForHighDRDY(); // Block until DRDY is high
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void updateMUX(uint8_t muxValue);
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inline void CS_LOW();
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inline void CS_HIGH();
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void updateConversionParameter(); // Refresh the conversion parameter based on the PGA
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float m_VREF = 0; // Value of the reference voltage
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float m_conversionParameter = 0; // PGA-dependent multiplier
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// Pins
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int8_t m_DRDY_pin; // Pin assigned for DRDY
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int8_t m_RESET_pin; // Pin assigned for RESET
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int8_t m_SYNC_pin; // Pin assigned for SYNC
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int8_t m_CS_pin; // Pin assigned for CS
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// Register values
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uint8_t m_DRATE; // Value of the DRATE register
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uint8_t m_ADCON; // Value of the ADCON register
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uint8_t m_MUX; // Value of the MUX register
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uint8_t m_PGA; // Value of the PGA (within ADCON)
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uint8_t m_GPIO; // Value of the GPIO register
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uint8_t m_STATUS; // Value of the status register
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uint8_t m_GPIOvalue; // GPIO value
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uint8_t m_ByteOrder; // Byte order
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uint8_t m_outputBuffer[3]; // 3-byte (24-bit) buffer for the fast acquisition - Single-channel, continuous
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int32_t m_outputValue; // Combined value of the m_outputBuffer[3]
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bool m_isAcquisitionRunning; // bool that keeps track of the acquisition (running or not)
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uint8_t m_cycle; // Tracks the cycles as the MUX is cycling through the input channels
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SemaphoreHandle_t m_drdyHigh;
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SemaphoreHandle_t m_drdyLow;
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};
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#endif |