Diff: Si7006A20.cpp

Revision:

0:cc2c5d49fe63

Child:

1:155934570c14

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Si7006A20.cpp	Mon Jul 10 17:14:44 2017 +0000
@@ -0,0 +1,386 @@
+/*******************************************************************************
+ * Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ *
+ * The library is modified to suite Si7006A20 Humidity and Temperature Sesor
+ * Made by Jurica Resetar @ aconno
+ * More info and contact: aconno.de
+ *
+ *******************************************************************************
+ */
+
+#include "Si7006A20.h"
+
+/***** Definitions *****/
+#define I2C_ADDR    (0x80)  // 1000000x
+#define POLYVAL     (0x131)
+
+/***** File Scope Data *****/
+static const char cmd_meas_humid[] = { 0xE5 };
+static const char cmd_meas_humid_no_hold[] = { 0xF5 };
+static const char cmd_meas_temp[] = { 0xE3 };
+static const char cmd_meas_temp_no_hold[] = { 0xF3 };
+static const char cmd_meas_prev_temp[] = { 0xE0 };
+static const char cmd_rst[] = { 0xFE };
+static const char cmd_write_user1[] = { 0xE6 };
+static const char cmd_read_user1[] = { 0xE7 };
+static const char cmd_id_1[] = { 0xFA, 0x0F };
+static const char cmd_id_2[] = { 0xFC, 0xC9 };
+static const char cmd_fw_ver[] = { 0x84, 0xB8 };
+
+//******************************************************************************
+Si7006::Si7006(PinName sda, PinName scl){
+    i2c_ = new I2C(sda, scl);
+    i2c_owner = true;
+
+    // 400KHz, as specified by the datasheet.
+    i2c_->frequency(400000);
+}
+
+//******************************************************************************
+Si7006::Si7006(I2C *i2c) : i2c_(i2c){
+    i2c_owner = false;
+}
+
+//******************************************************************************
+Si7006::~Si7006(){
+    if(i2c_owner) {
+        delete i2c_;
+    }
+}
+
+//******************************************************************************
+int Si7006::reset(void){
+    if (i2c_->write(I2C_ADDR, cmd_rst, sizeof(cmd_rst)) != 0) {
+        return -1;
+    }
+    return 0;
+}
+
+//******************************************************************************
+int Si7006::getElectronicId(char* id){
+    // Send cmd with repeated start
+    if (i2c_->write(I2C_ADDR, cmd_id_1, sizeof(cmd_id_1), true) != 0) {
+        return -1;
+    }
+
+    // Read first portion of ID
+    char temp[8];
+    if (i2c_->read(I2C_ADDR, temp, 8, false) != 0) {
+        return -1;
+    }
+
+    // Check the CRC
+    char crc = 0;
+    int i;
+    for(i = 0; i < 4; i++) {
+        crc = crc8(temp[2*i], crc);
+        if(crc != temp[2*i +1]) {
+            return -1;
+        }
+    }
+
+    // Save top portion of ID
+    id[7] = temp [0];
+    id[6] = temp [2];
+    id[5] = temp [4];
+    id[4] = temp [6];
+
+    // Send cmd with repeated start
+    if (i2c_->write(I2C_ADDR, cmd_id_2, sizeof(cmd_id_2), true) != 0) {
+        return -1;
+    }
+
+    // Read rest of ID
+    if (i2c_->read(I2C_ADDR, temp, 6, false) != 0) {
+        return -1;
+    }
+
+    // Check the CRC
+    crc = 0;
+    for(i = 0; i < 2; i++) {
+        crc = crc8(temp[3*i], crc);
+        crc = crc8(temp[3*i + 1], crc);
+        if(crc != temp[3*i + 2]) {
+            return -1;
+        }
+    }
+
+    // Save bottom portion of ID
+    id[3] = temp [0];
+    id[2] = temp [1];
+    id[1] = temp [3];
+    id[0] = temp [4];
+
+    return 0;
+}
+
+//******************************************************************************
+int Si7006::configResolution(Si7006::resolution_t resolution){
+    char data[2];
+
+    if (i2c_->write(I2C_ADDR, cmd_read_user1, sizeof(cmd_read_user1)) != 0) {
+        return -1;
+    }
+
+    if (i2c_->read(I2C_ADDR, &data[1], 1) != 0) {
+        return -1;
+    }
+
+    switch (resolution) {
+        case RH_12b_TEMP_14b:
+            data[1] &= ~0x81;
+            break;
+        case RH_8b_TEMP_12b:
+            data[1] = (data[1] & ~0x80) | 0x01;
+            break;
+        case RH_10b_TEMP_13b:
+            data[1] = (data[1] & ~0x01) | 0x80;
+            break;
+        case RH_11b_TEMP_11b:
+            data[1] |= 0x81;
+            break;
+        default:
+            return -1;
+    }
+
+    data[0] = cmd_write_user1[0];
+
+    if (i2c_->write(I2C_ADDR, data, 2) != 0) {
+        return -1;
+    }
+
+    return 0;
+}
+
+//******************************************************************************
+int Si7006::getTemperature(int16_t *tempCx10){
+    if (i2c_->write(I2C_ADDR, cmd_meas_temp, sizeof(cmd_meas_temp)) != 0) {
+        return -1;
+    }
+
+    return checkTemperature(tempCx10);
+}
+
+//******************************************************************************
+int Si7006::getTemperature(float *tempC){
+    if (i2c_->write(I2C_ADDR, cmd_meas_temp, sizeof(cmd_meas_temp)) != 0) {
+        return -1;
+    }
+
+    return checkTemperature(tempC);
+}
+
+//******************************************************************************
+int Si7006::startTemperature(void){
+    if (i2c_->write(I2C_ADDR, cmd_meas_temp_no_hold, sizeof(cmd_meas_temp_no_hold)) != 0) {
+        return -1;
+    }
+
+    return 0;
+}
+
+//******************************************************************************
+int Si7006::checkTemperature(int16_t *tempCx10){
+    char data[3];
+    uint16_t code;
+    int temp;
+
+    if (i2c_->read(I2C_ADDR, data, 3) != 0) {
+        return -1;
+    }
+
+    // Get 16-bit value from bytes read
+    code = ((uint16_t)data[0] << 8) + data[1];
+
+    // Calculate the temperature using the formula from the datasheet
+    // Scaled by 100
+    temp = ((((int)17572 * code) + 0x8000) >> 16) - 4685;
+
+    // Return value is to be scaled by 10
+    *tempCx10 = (temp + 5) / 10;
+    
+    return 0;
+}
+
+//******************************************************************************
+int Si7006::checkTemperature(float *tempC){
+    char data[3];
+    uint16_t code;
+
+    if (i2c_->read(I2C_ADDR, data, 3) != 0) {
+        return -1;
+    }
+
+    // Get 16-bit value from bytes read
+    code = ((uint16_t)data[0] << 8) + data[1];
+
+    // Calculate the temperature using the formula from the datasheet
+    // Scaled by 100
+    *tempC = (((float)175.72 * code) / 65536) - 46.85;
+
+    return 0;
+}
+
+//******************************************************************************
+int Si7006::getHumidity(int16_t *humidx10){
+    if (i2c_->write(I2C_ADDR, cmd_meas_humid, sizeof(cmd_meas_humid), true) != 0) {
+        //return -1;
+    }
+    wait_ms(100);
+    return checkHumidity(humidx10);
+}
+
+//******************************************************************************
+int Si7006::getHumidity(float *humid){
+    if (i2c_->write(I2C_ADDR, cmd_meas_humid, sizeof(cmd_meas_humid)) != 0) {
+        //return -1;
+    }
+    wait_ms(100);
+    return checkHumidity(humid);
+}
+
+//******************************************************************************
+int Si7006::startHumidity(void){
+    if (i2c_->write(I2C_ADDR, cmd_meas_humid_no_hold, sizeof(cmd_meas_humid_no_hold)) != 0) {
+        return -1;
+    }
+
+    return 0;
+}
+
+//******************************************************************************
+int Si7006::checkHumidity(int16_t *humidx10){
+    char data[3];
+    uint16_t code;
+
+    if (i2c_->read(I2C_ADDR, data, 3) != 0) {
+        return -1;
+    }
+
+    // Get 16-bit value from bytes read
+    code = ((uint16_t)data[0] << 8) + data[1];
+
+    // Calculate the humidity using the formula from the datasheet
+    // Scaled by 10
+    *humidx10 = ((((int)1250 * code) + 0x8000) >> 16) - 60;
+
+    // Check the crc
+    char crc = crc8(data[0], 0x00);
+    crc = crc8(data[1], crc);
+    if(crc != data[2]) {
+        return -1;
+    }
+
+    return 0;
+}
+
+//******************************************************************************
+int Si7006::checkHumidity(float *humid){
+    char data[3];
+    uint16_t code;
+
+    if (i2c_->read(I2C_ADDR, data, 3) != 0) {
+        return -1;
+    }
+
+    // Get 16-bit value from bytes read
+    code = ((uint16_t)data[0] << 8) + data[1];
+
+    // Calculate the humidity using the formula from the datasheet
+    *humid = (((float)125 * code) / 65536) - 6;
+
+    return 0;
+}
+
+//******************************************************************************
+int Si7006::getPrevTemperature(float *tempC) {
+    if (i2c_->write(I2C_ADDR, cmd_meas_prev_temp, sizeof(cmd_meas_prev_temp)) != 0) {
+        return -1;
+    }
+    if(checkTemperature(tempC) != 0) {
+        return -1;
+    }
+    return 0;
+}
+
+//******************************************************************************
+int Si7006::getPrevTemperature(int16_t *tempCx10) {
+    if (i2c_->write(I2C_ADDR, cmd_meas_prev_temp, sizeof(cmd_meas_prev_temp)) != 0) {
+        return -1;
+    }
+    if(checkTemperature(tempCx10) != 0) {
+        return -1;
+    }
+    return 0;
+}
+
+//******************************************************************************
+int Si7006::getRev(char *rev){
+    if (i2c_->write(I2C_ADDR, cmd_fw_ver, sizeof(cmd_fw_ver)) != 0) {
+        return -1;
+    }
+    if (i2c_->read(I2C_ADDR, rev, 1) != 0) {
+        return -1;
+    }
+    
+    return 0;
+}
+
+//******************************************************************************
+int Si7006::heater(bool enable)
+{
+    char data[2];
+
+    if (i2c_->write(I2C_ADDR, cmd_read_user1, sizeof(cmd_read_user1)) != 0) {
+        return -1;
+    }
+
+    if (i2c_->read(I2C_ADDR, &data[1], 1) != 0) {
+        return -1;
+    }
+
+    if (enable) {
+        data[1] |= 0x04;
+    } else {
+        data[1] &= ~0x04;
+    }
+
+    data[0] = cmd_write_user1[0];
+
+    if (i2c_->write(I2C_ADDR, data, 2) != 0) {
+        return -1;
+    }
+
+    return 0;
+}
+
+//******************************************************************************
+char Si7006::crc8(char value, char seed)
+{
+    int i;
+
+    for (i = 0; i < 8; i++) {
+
+        if ((value ^ seed) & 0x80) {
+            seed <<= 1;
+            seed ^= POLYVAL;
+        } else {
+            seed <<= 1;
+        }
+
+        value <<= 1;
+    }
+
+    return seed;
+}