Analog Devices / mbed-drivers

A collection of Analog Devices drivers for the mbed platform

For additional information check out the mbed page of the Analog Devices wiki: https://wiki.analog.com/resources/tools-software/mbed-drivers-all

libraries/CN0216/CN0216.cpp@33:c3ec596a29c2, 2016-11-07 (annotated)

Committer:
Adrian Suciu
Date:
Mon Nov 07 16:27:12 2016 +0200
Revision:
33:c3ec596a29c2
Parent:
24:dae7123d432a 
Added CN0391, CN0396 and CN0397 shields

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Adrian Suciu 24:dae7123d432a 1 /**
Adrian Suciu 24:dae7123d432a 2 * @file cn0216.cpp
Adrian Suciu 24:dae7123d432a 3 * @brief Source file for CN0216
Adrian Suciu 24:dae7123d432a 4 * @author Analog Devices Inc.
Adrian Suciu 24:dae7123d432a 5 *
Adrian Suciu 24:dae7123d432a 6 * For support please go to:
Adrian Suciu 24:dae7123d432a 7 * Github: https://github.com/analogdevicesinc/mbed-adi
Adrian Suciu 24:dae7123d432a 8 * Support: https://ez.analog.com/community/linux-device-drivers/microcontroller-no-os-drivers
Adrian Suciu 24:dae7123d432a 9 * Product: www.analog.com/EVAL-CN0216-ARDZ
Adrian Suciu 24:dae7123d432a 10 * More: https://wiki.analog.com/resources/tools-software/mbed-drivers-all
Adrian Suciu 24:dae7123d432a 11
Adrian Suciu 24:dae7123d432a 12 ********************************************************************************
Adrian Suciu 24:dae7123d432a 13 * Copyright 2016(c) Analog Devices, Inc.
Adrian Suciu 24:dae7123d432a 14 *
Adrian Suciu 24:dae7123d432a 15 * All rights reserved.
Adrian Suciu 24:dae7123d432a 16 *
Adrian Suciu 24:dae7123d432a 17 * Redistribution and use in source and binary forms, with or without
Adrian Suciu 24:dae7123d432a 18 * modification, are permitted provided that the following conditions are met:
Adrian Suciu 24:dae7123d432a 19 * - Redistributions of source code must retain the above copyright
Adrian Suciu 24:dae7123d432a 20 * notice, this list of conditions and the following disclaimer.
Adrian Suciu 24:dae7123d432a 21 * - Redistributions in binary form must reproduce the above copyright
Adrian Suciu 24:dae7123d432a 22 * notice, this list of conditions and the following disclaimer in
Adrian Suciu 24:dae7123d432a 23 * the documentation and/or other materials provided with the
Adrian Suciu 24:dae7123d432a 24 * distribution.
Adrian Suciu 24:dae7123d432a 25 * - Neither the name of Analog Devices, Inc. nor the names of its
Adrian Suciu 24:dae7123d432a 26 * contributors may be used to endorse or promote products derived
Adrian Suciu 24:dae7123d432a 27 * from this software without specific prior written permission.
Adrian Suciu 24:dae7123d432a 28 * - The use of this software may or may not infringe the patent rights
Adrian Suciu 24:dae7123d432a 29 * of one or more patent holders. This license does not release you
Adrian Suciu 24:dae7123d432a 30 * from the requirement that you obtain separate licenses from these
Adrian Suciu 24:dae7123d432a 31 * patent holders to use this software.
Adrian Suciu 24:dae7123d432a 32 * - Use of the software either in source or binary form, must be run
Adrian Suciu 24:dae7123d432a 33 * on or directly connected to an Analog Devices Inc. component.
Adrian Suciu 24:dae7123d432a 34 *
Adrian Suciu 24:dae7123d432a 35 * THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR
Adrian Suciu 24:dae7123d432a 36 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT,
Adrian Suciu 24:dae7123d432a 37 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
Adrian Suciu 24:dae7123d432a 38 * IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT,
Adrian Suciu 24:dae7123d432a 39 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
Adrian Suciu 24:dae7123d432a 40 * LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, PROCUREMENT OF SUBSTITUTE GOODS OR
Adrian Suciu 24:dae7123d432a 41 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
Adrian Suciu 24:dae7123d432a 42 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
Adrian Suciu 24:dae7123d432a 43 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
Adrian Suciu 24:dae7123d432a 44 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Adrian Suciu 24:dae7123d432a 45 *
Adrian Suciu 24:dae7123d432a 46 ********************************************************************************/
Adrian Suciu 24:dae7123d432a 47
Adrian Suciu 24:dae7123d432a 48 #include "mbed.h"
Adrian Suciu 24:dae7123d432a 49 #include "AD7791.h"
Adrian Suciu 24:dae7123d432a 50 #include "CN0216.h"
Adrian Suciu 24:dae7123d432a 51 extern Serial pc;
Adrian Suciu 24:dae7123d432a 52
Adrian Suciu 24:dae7123d432a 53 /**
Adrian Suciu 24:dae7123d432a 54 * CN0216 constructor
Adrian Suciu 24:dae7123d432a 55 * @param CSAD7791 - Chipselect of the AD7791
Adrian Suciu 24:dae7123d432a 56 * @param MOSI - MOSI line of the SPI bus
Adrian Suciu 24:dae7123d432a 57 * @param MISO - MISO line of the SPI bus
Adrian Suciu 24:dae7123d432a 58 * @param SCK - SCK line of the SPI bus
Adrian Suciu 24:dae7123d432a 59 */
Adrian Suciu 24:dae7123d432a 60 CN0216::CN0216(PinName CSAD7791, PinName MOSI, PinName MISO, PinName SCK) : ad7791(1.2, CSAD7791, MOSI, MISO, SCK)
Adrian Suciu 24:dae7123d432a 61 {
Adrian Suciu 24:dae7123d432a 62 _cal_weight = 0;
Adrian Suciu 24:dae7123d432a 63 _zero_scale_value = 0;
Adrian Suciu 24:dae7123d432a 64 _full_scale_value = 0;
Adrian Suciu 24:dae7123d432a 65 _weight_units_per_bit = 0;
Adrian Suciu 24:dae7123d432a 66 }
Adrian Suciu 24:dae7123d432a 67
Adrian Suciu 24:dae7123d432a 68 /**
Adrian Suciu 24:dae7123d432a 69 * Initializes the mode and filter values of the AD7791 and sets the weight to be used in calibration
Adrian Suciu 24:dae7123d432a 70 * @param cal_weight - weight used in calibration
Adrian Suciu 24:dae7123d432a 71 * @param mode_val - value of the mode register
Adrian Suciu 24:dae7123d432a 72 * @param filter_val - value of the filter register
Adrian Suciu 24:dae7123d432a 73 */
Adrian Suciu 24:dae7123d432a 74 void CN0216::init(float cal_weight, uint8_t mode_val, uint8_t filter_val)
Adrian Suciu 24:dae7123d432a 75 {
Adrian Suciu 24:dae7123d432a 76 _cal_weight = cal_weight;
Adrian Suciu 24:dae7123d432a 77 ad7791.frequency(500000);
Adrian Suciu 24:dae7123d432a 78 wait_ms(50);
Adrian Suciu 24:dae7123d432a 79 ad7791.reset();
Adrian Suciu 24:dae7123d432a 80 wait_ms(50);
Adrian Suciu 24:dae7123d432a 81 ad7791.write_mode_reg(mode_val);
Adrian Suciu 24:dae7123d432a 82 wait_us(2);
Adrian Suciu 24:dae7123d432a 83 ad7791.write_filter_reg(filter_val);
Adrian Suciu 24:dae7123d432a 84 wait_ms(50);
Adrian Suciu 24:dae7123d432a 85 }
Adrian Suciu 24:dae7123d432a 86
Adrian Suciu 24:dae7123d432a 87 /**
Adrian Suciu 24:dae7123d432a 88 * Calibrates the CN0216 weigh scale
Adrian Suciu 24:dae7123d432a 89 * @param cal - calibration step.
Adrian Suciu 24:dae7123d432a 90 * Step CN0216::ZERO_SCALE_CALIBRATION will take CN0216::_NUMBER_OF_SAMPLES samples and use the minimum as value for the zero scale
Adrian Suciu 24:dae7123d432a 91 * Step CN0216::FULL_SCALE_CALIBRATION will take CN0216::_NUMBER_OF_SAMPLES samples and use the average as value for the full scale
Adrian Suciu 24:dae7123d432a 92 * Step COMPUTE_UNITS_PER_BIT will compute the grams per bit used in weight computation.
Adrian Suciu 24:dae7123d432a 93 */
Adrian Suciu 24:dae7123d432a 94 void CN0216::calibrate(CalibrationStep_t cal)
Adrian Suciu 24:dae7123d432a 95 {
Adrian Suciu 24:dae7123d432a 96 uint64_t sum = 0;
Adrian Suciu 24:dae7123d432a 97 uint32_t min = 0xFFFFFFFF;
Adrian Suciu 24:dae7123d432a 98 uint32_t sample = 0;
Adrian Suciu 24:dae7123d432a 99 switch(cal) {
Adrian Suciu 24:dae7123d432a 100 case ZERO_SCALE_CALIBRATION:
Adrian Suciu 24:dae7123d432a 101 case FULL_SCALE_CALIBRATION:
Adrian Suciu 24:dae7123d432a 102 for(int i = 0; i < _NUMBER_OF_SAMPLES; i++) {
Adrian Suciu 24:dae7123d432a 103 sample = ad7791.read_u32();
Adrian Suciu 24:dae7123d432a 104 min = (min < sample) ? min : sample;
Adrian Suciu 24:dae7123d432a 105 sum += ad7791.read_u32();
Adrian Suciu 24:dae7123d432a 106 wait_us(5);
Adrian Suciu 24:dae7123d432a 107 }
Adrian Suciu 24:dae7123d432a 108 if(cal == ZERO_SCALE_CALIBRATION) {
Adrian Suciu 24:dae7123d432a 109 // pc.printf("ZERO SCALE VALUE = %x",sum);
Adrian Suciu 24:dae7123d432a 110 _zero_scale_value = min;
Adrian Suciu 24:dae7123d432a 111 } else {
Adrian Suciu 24:dae7123d432a 112 // pc.printf("FULL SCALE VALUE = %x",sum);
Adrian Suciu 24:dae7123d432a 113 sum = sum / _NUMBER_OF_SAMPLES;
Adrian Suciu 24:dae7123d432a 114 _full_scale_value = sum;
Adrian Suciu 24:dae7123d432a 115 }
Adrian Suciu 24:dae7123d432a 116 break;
Adrian Suciu 24:dae7123d432a 117
Adrian Suciu 24:dae7123d432a 118 case COMPUTE_UNITS_PER_BIT:
Adrian Suciu 24:dae7123d432a 119 _weight_units_per_bit = _cal_weight / (static_cast<float> (_full_scale_value - _zero_scale_value)); /* Calculate number of grams per LSB */
Adrian Suciu 24:dae7123d432a 120 // pc.printf("GRAMS/LSB = %f", _grams_per_bit);
Adrian Suciu 24:dae7123d432a 121 break;
Adrian Suciu 24:dae7123d432a 122 default:
Adrian Suciu 24:dae7123d432a 123 break;
Adrian Suciu 24:dae7123d432a 124 }
Adrian Suciu 24:dae7123d432a 125
Adrian Suciu 24:dae7123d432a 126 }
Adrian Suciu 24:dae7123d432a 127
Adrian Suciu 24:dae7123d432a 128 /**
Adrian Suciu 24:dae7123d432a 129 * Computes the weight based on the formula
Adrian Suciu 24:dae7123d432a 130 * weight = (data - zeroscale) * weight_units_per_bit
Adrian Suciu 24:dae7123d432a 131 * @param data read from the ADC
Adrian Suciu 24:dae7123d432a 132 * @return weight based on data
Adrian Suciu 24:dae7123d432a 133 */
Adrian Suciu 24:dae7123d432a 134 float CN0216::compute_weight(uint32_t data)
Adrian Suciu 24:dae7123d432a 135 {
Adrian Suciu 24:dae7123d432a 136 // pc.printf("\r\nFULL_SCALE_VALUE = %x\r\nZERO_SCALE_VALUE = %x\r\nDATA READ = %x\r\nGRAMS/LSB = %f\r\n",_full_scale_value,data,_zero_scale_value,_grams_per_bit);
Adrian Suciu 24:dae7123d432a 137 if(data < _zero_scale_value)
Adrian Suciu 24:dae7123d432a 138 data = _zero_scale_value; // clamp data to 0
Adrian Suciu 24:dae7123d432a 139 float weight_in_grams = (static_cast<float>((data) - _zero_scale_value)) * _weight_units_per_bit; /* Calculate weight */
Adrian Suciu 24:dae7123d432a 140 return weight_in_grams;
Adrian Suciu 24:dae7123d432a 141 }
Adrian Suciu 24:dae7123d432a 142
Adrian Suciu 24:dae7123d432a 143 /**
Adrian Suciu 24:dae7123d432a 144 * Reads the AD7791
Adrian Suciu 24:dae7123d432a 145 * @return value read by the ADC
Adrian Suciu 24:dae7123d432a 146 */
Adrian Suciu 24:dae7123d432a 147 uint32_t CN0216::read_u32()
Adrian Suciu 24:dae7123d432a 148 {
Adrian Suciu 24:dae7123d432a 149 return ad7791.read_u32();
Adrian Suciu 24:dae7123d432a 150 }
Adrian Suciu 24:dae7123d432a 151
Adrian Suciu 24:dae7123d432a 152 /**
Adrian Suciu 24:dae7123d432a 153 * Reads the ADC and computes the weight based on the formula described above.
Adrian Suciu 24:dae7123d432a 154 * @return weight
Adrian Suciu 24:dae7123d432a 155 */
Adrian Suciu 24:dae7123d432a 156 float CN0216::read_weight()
Adrian Suciu 24:dae7123d432a 157 {
Adrian Suciu 24:dae7123d432a 158 uint32_t weight = read_u32();
Adrian Suciu 24:dae7123d432a 159 return compute_weight(weight);
Adrian Suciu 24:dae7123d432a 160 }
Adrian Suciu 24:dae7123d432a 161