CJ Shaw / HY3116

Library for working with the HYCON HY3116/8 24-bit weigh-scales ADC series.

HY3116.cpp@8:530aad60c490, 2016-07-26 (annotated)

Committer:
seajayshore
Date:
Tue Jul 26 16:26:35 2016 +0000
Revision:
8:530aad60c490
Parent:
7:c9a0ce000a18 
Refactoring & re-organisation with true C++ constructors.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
seajayshore 0:80768ca5d5ff 1 #include "HY3116.h"
seajayshore 0:80768ca5d5ff 2
seajayshore 8:530aad60c490 3 /**
seajayshore 8:530aad60c490 4 * Default Constructor.
seajayshore 8:530aad60c490 5 * Sets default I2C pins with default frequency
seajayshore 8:530aad60c490 6 */
seajayshore 8:530aad60c490 7 HY3116::HY3116() :
seajayshore 8:530aad60c490 8 i2c(p22, p21)
seajayshore 8:530aad60c490 9 {
seajayshore 8:530aad60c490 10
seajayshore 8:530aad60c490 11 // Set the I2C clock frequency
seajayshore 8:530aad60c490 12 i2c.frequency(250000);
seajayshore 8:530aad60c490 13 } // End constructor
seajayshore 3:535ed9a0ce59 14
seajayshore 8:530aad60c490 15 /**
seajayshore 8:530aad60c490 16 * Constructor #2
seajayshore 8:530aad60c490 17 * Sets I2C pins with default frequency
seajayshore 8:530aad60c490 18 */
seajayshore 8:530aad60c490 19 HY3116::HY3116(PinName sda,
seajayshore 8:530aad60c490 20 PinName scl) :
seajayshore 8:530aad60c490 21 i2c(sda, scl)
seajayshore 8:530aad60c490 22 {
seajayshore 8:530aad60c490 23
seajayshore 8:530aad60c490 24 // Set the I2C clock frequency
seajayshore 8:530aad60c490 25 i2c.frequency(250000);
seajayshore 8:530aad60c490 26 } // End constructor
seajayshore 8:530aad60c490 27
seajayshore 8:530aad60c490 28 /**
seajayshore 8:530aad60c490 29 * Constructor #3
seajayshore 8:530aad60c490 30 * Sets I2C pins and non-default frequency
seajayshore 8:530aad60c490 31 */
seajayshore 8:530aad60c490 32 HY3116::HY3116(PinName sda,
seajayshore 8:530aad60c490 33 PinName scl,
seajayshore 8:530aad60c490 34 int freq ) :
seajayshore 8:530aad60c490 35 i2c(sda, scl)
seajayshore 8:530aad60c490 36 {
seajayshore 8:530aad60c490 37
seajayshore 8:530aad60c490 38 // Set the I2C clock frequency
seajayshore 8:530aad60c490 39 i2c.frequency(freq);
seajayshore 8:530aad60c490 40 } // End constructor
seajayshore 3:535ed9a0ce59 41
seajayshore 8:530aad60c490 42 /**
seajayshore 8:530aad60c490 43 * Destructor.
seajayshore 8:530aad60c490 44 */
seajayshore 8:530aad60c490 45 HY3116::~HY3116()
seajayshore 8:530aad60c490 46 {
seajayshore 8:530aad60c490 47
seajayshore 8:530aad60c490 48 }
seajayshore 8:530aad60c490 49
seajayshore 8:530aad60c490 50 /**
seajayshore 8:530aad60c490 51 * Helper function to write correct data to HY3116 registers
seajayshore 8:530aad60c490 52 */
seajayshore 8:530aad60c490 53 int HY3116::writeRegister(uint8_t regAddress, uint8_t writeData)
seajayshore 8:530aad60c490 54 {
seajayshore 8:530aad60c490 55 int retval = 1;
seajayshore 8:530aad60c490 56 char writeBuffer[2];
seajayshore 8:530aad60c490 57 writeBuffer[0]=regAddress;
seajayshore 8:530aad60c490 58 writeBuffer[1]=writeData;
seajayshore 8:530aad60c490 59 retval = i2c.write(HY3116_ADDRESS,writeBuffer,sizeof(writeBuffer),0);
seajayshore 8:530aad60c490 60 if (retval != 0) {
seajayshore 8:530aad60c490 61 return retval;
seajayshore 8:530aad60c490 62 }
seajayshore 8:530aad60c490 63 return 0;
seajayshore 8:530aad60c490 64 }
seajayshore 0:80768ca5d5ff 65
seajayshore 8:530aad60c490 66 /**
seajayshore 8:530aad60c490 67 * Helper function to write correct data to HY3116 registers
seajayshore 8:530aad60c490 68 */
seajayshore 8:530aad60c490 69 int HY3116::readRegister(uint8_t regAddress, uint8_t byteNum, uint8_t* dest)
seajayshore 0:80768ca5d5ff 70 {
seajayshore 8:530aad60c490 71 int retval = 1;
seajayshore 8:530aad60c490 72 if (byteNum > sizeof(dest)) {
seajayshore 8:530aad60c490 73 return retval;
seajayshore 7:c9a0ce000a18 74 }
seajayshore 8:530aad60c490 75 char writeBuffer[1];
seajayshore 8:530aad60c490 76 writeBuffer[0] = regAddress;
seajayshore 8:530aad60c490 77 char readBuffer[byteNum];
seajayshore 8:530aad60c490 78 retval = i2c.write(HY3116_ADDRESS,writeBuffer,sizeof(writeBuffer),1);
seajayshore 8:530aad60c490 79 if (retval != 0) {
seajayshore 8:530aad60c490 80 return retval;
seajayshore 8:530aad60c490 81 }
seajayshore 8:530aad60c490 82 retval = i2c.read(HY3116_ADDRESS,readBuffer,sizeof(readBuffer),0);
seajayshore 8:530aad60c490 83 if (retval != 0) {
seajayshore 8:530aad60c490 84 return retval;
seajayshore 8:530aad60c490 85 }
seajayshore 8:530aad60c490 86 for(int i=0; i<byteNum; i++) {
seajayshore 8:530aad60c490 87 dest[i]=readBuffer[i];
seajayshore 8:530aad60c490 88 }
seajayshore 8:530aad60c490 89 return 0;
seajayshore 0:80768ca5d5ff 90 }
seajayshore 0:80768ca5d5ff 91
seajayshore 0:80768ca5d5ff 92 // Function to send the reset command
seajayshore 7:c9a0ce000a18 93 int HY3116::resetChip()
seajayshore 0:80768ca5d5ff 94 {
seajayshore 8:530aad60c490 95 int retval = 0;
seajayshore 8:530aad60c490 96 char writeBuffer[1];
seajayshore 8:530aad60c490 97 writeBuffer[0] = RESET;
seajayshore 8:530aad60c490 98 retval = i2c.write(RESET_ADDRESS,writeBuffer,sizeof(writeBuffer),0);
seajayshore 8:530aad60c490 99 if (retval != 0) {
seajayshore 7:c9a0ce000a18 100 return 1;
seajayshore 7:c9a0ce000a18 101 }
seajayshore 7:c9a0ce000a18 102 return 0;
seajayshore 0:80768ca5d5ff 103 }
seajayshore 0:80768ca5d5ff 104
seajayshore 0:80768ca5d5ff 105 // Dedicated ADC-output read, check & format function
seajayshore 7:c9a0ce000a18 106 uint8_t HY3116::readAdc(int32_t *_adcReading)
seajayshore 0:80768ca5d5ff 107 {
seajayshore 1:1967c3f48465 108 // Initialise function variables
seajayshore 0:80768ca5d5ff 109 uint8_t rawData[3];
seajayshore 0:80768ca5d5ff 110 bool newReading = 0;
seajayshore 0:80768ca5d5ff 111 int32_t adcReading = 0;
seajayshore 7:c9a0ce000a18 112 uint8_t adc_error = 0;
seajayshore 7:c9a0ce000a18 113 uint8_t returnError = 0;
seajayshore 0:80768ca5d5ff 114
seajayshore 1:1967c3f48465 115 // Read in the raw ADO bytes
seajayshore 8:530aad60c490 116 adc_error = readRegister(ADO, 3, &rawData[0]);
seajayshore 7:c9a0ce000a18 117 if (adc_error != 0) {
seajayshore 7:c9a0ce000a18 118 returnError = 2;
seajayshore 7:c9a0ce000a18 119 return returnError;
seajayshore 7:c9a0ce000a18 120 }
seajayshore 0:80768ca5d5ff 121
seajayshore 1:1967c3f48465 122 // Test if there is new data (polling mode)
seajayshore 0:80768ca5d5ff 123 if (rawData[2] & 0b00000001) {
seajayshore 1:1967c3f48465 124
seajayshore 1:1967c3f48465 125 // Set the newReading flag
seajayshore 7:c9a0ce000a18 126 returnError = 0;
seajayshore 1:1967c3f48465 127
seajayshore 1:1967c3f48465 128 // Shift the raw bytes into the 32-bit variable
seajayshore 1:1967c3f48465 129 adcReading += rawData[0] << 15;
seajayshore 1:1967c3f48465 130 adcReading += rawData[1] << 7;
seajayshore 1:1967c3f48465 131 adcReading += rawData[2] >> 1;
seajayshore 1:1967c3f48465 132
seajayshore 1:1967c3f48465 133 // Account for twos complement polarity
seajayshore 1:1967c3f48465 134 if (rawData[0] & 0b10000000) {
seajayshore 1:1967c3f48465 135 adcReading ^= 0xFF800000;
seajayshore 1:1967c3f48465 136 }
seajayshore 0:80768ca5d5ff 137 }
seajayshore 0:80768ca5d5ff 138 else {
seajayshore 1:1967c3f48465 139
seajayshore 1:1967c3f48465 140 // Set the newReading flag
seajayshore 7:c9a0ce000a18 141 returnError = 1;
seajayshore 0:80768ca5d5ff 142 }
seajayshore 0:80768ca5d5ff 143
seajayshore 1:1967c3f48465 144 *_adcReading = adcReading;
seajayshore 0:80768ca5d5ff 145
seajayshore 7:c9a0ce000a18 146 return returnError;
seajayshore 0:80768ca5d5ff 147 }
seajayshore 0:80768ca5d5ff 148
seajayshore 0:80768ca5d5ff 149 // Initialise the HY3116 with the following config.:
seajayshore 0:80768ca5d5ff 150 //
seajayshore 7:c9a0ce000a18 151 bool HY3116::init()
seajayshore 0:80768ca5d5ff 152 {
seajayshore 7:c9a0ce000a18 153 int adc_error = 0;
seajayshore 7:c9a0ce000a18 154
seajayshore 8:530aad60c490 155 // Reset the chip
seajayshore 8:530aad60c490 156 adc_error = resetChip();
seajayshore 8:530aad60c490 157 if (adc_error != 0) {
seajayshore 8:530aad60c490 158 return 0;
seajayshore 8:530aad60c490 159 }
seajayshore 8:530aad60c490 160 wait_ms(1);
seajayshore 0:80768ca5d5ff 161
seajayshore 0:80768ca5d5ff 162 // Set-up the SYS register
seajayshore 8:530aad60c490 163 adc_error = writeRegister(SYS, 0b00011100); // Enable the ADC & LDO
seajayshore 7:c9a0ce000a18 164 if (adc_error != 0) {
seajayshore 7:c9a0ce000a18 165 return 0;
seajayshore 7:c9a0ce000a18 166 }
seajayshore 2:2da9fbab02b7 167 wait_ms(1); // wait 100 ms to stabilize
seajayshore 0:80768ca5d5ff 168
seajayshore 0:80768ca5d5ff 169 // Set-up the ADC1 register
seajayshore 8:530aad60c490 170 adc_error = writeRegister(ADC1, 0b00001000); // Set inputs to AIN1 & AIN2
seajayshore 7:c9a0ce000a18 171 if (adc_error != 0) {
seajayshore 7:c9a0ce000a18 172 return 0;
seajayshore 7:c9a0ce000a18 173 }
seajayshore 2:2da9fbab02b7 174 wait_ms(1); // wait 100 ms to stabilize
seajayshore 0:80768ca5d5ff 175
seajayshore 0:80768ca5d5ff 176 // Set-up the ADC2 register
seajayshore 8:530aad60c490 177 adc_error = writeRegister(ADC2, 0b01010000); // Set pos. ref. voltage to VDDA, neg. ref. to VSSA, DC offset to 0VRef
seajayshore 7:c9a0ce000a18 178 if (adc_error != 0) {
seajayshore 7:c9a0ce000a18 179 return 0;
seajayshore 7:c9a0ce000a18 180 }
seajayshore 2:2da9fbab02b7 181 wait_ms(1); // wait 100 ms to stabilize
seajayshore 0:80768ca5d5ff 182
seajayshore 0:80768ca5d5ff 183 // Set-up the ADC3 register
seajayshore 8:530aad60c490 184 adc_error = writeRegister(ADC3, 0b00111111); // Set to int. osc. 327kHz, full ref. range, PGA to 32x, pre-amp to 2x
seajayshore 7:c9a0ce000a18 185 if (adc_error != 0) {
seajayshore 7:c9a0ce000a18 186 return 0;
seajayshore 7:c9a0ce000a18 187 }
seajayshore 2:2da9fbab02b7 188 wait_ms(1); // wait 100 ms to stabilize
seajayshore 0:80768ca5d5ff 189
seajayshore 0:80768ca5d5ff 190 // Set-up the ADC4 register
seajayshore 5:3fdbe36e5057 191 // [0:1] = LDO voltage select, 01 = 3.0V
seajayshore 5:3fdbe36e5057 192 // [2] = REFO voltage, 0 = 1.2V
seajayshore 5:3fdbe36e5057 193 // [3] = HS conversion rate, 0 = slow (327kHz)
seajayshore 5:3fdbe36e5057 194 // [4:6] = OSR ADC output rate, 110 = 40SPS (when HS = 0)
seajayshore 5:3fdbe36e5057 195 // [7] = N/A
seajayshore 8:530aad60c490 196 adc_error = writeRegister(ADC4, 0b01001100);
seajayshore 7:c9a0ce000a18 197 if (adc_error != 0) {
seajayshore 7:c9a0ce000a18 198 return 0;
seajayshore 7:c9a0ce000a18 199 }
seajayshore 5:3fdbe36e5057 200 wait_ms(1); // Wait to stabilise
seajayshore 0:80768ca5d5ff 201
seajayshore 7:c9a0ce000a18 202 return 1;
seajayshore 0:80768ca5d5ff 203 }