Hexiwear / Mbed OS Hexi_Click_AirQuality_Example

Important changes to repositories hosted on mbed.com

Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.

To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.

It is also possible to export all your personal repositories from the account settings page.

Dependencies:   Hexi_KW40Z Hexi_OLED_SSD1351

main.cpp@1:7b9c19276087, 2016-10-21 (annotated)

Committer:
daveyclk
Date:
Fri Oct 21 13:20:11 2016 +0000
Revision:
1:7b9c19276087
Parent:
0:4cf89612afab
Child:
2:8e7d89c2cbde
Updated CalculatePPM() with correct 16bit ADC values and ref voltages

Who changed what in which revision?

UserRevisionLine numberNew contents of line
GregC 0:4cf89612afab 1 /******************************************************************************
GregC 0:4cf89612afab 2 * Includes
GregC 0:4cf89612afab 3 *******************************************************************************/
GregC 0:4cf89612afab 4
GregC 0:4cf89612afab 5 #include "mbed.h"
GregC 0:4cf89612afab 6 #include "Hexi_OLED_SSD1351.h"
GregC 0:4cf89612afab 7 #include "images.h"
GregC 0:4cf89612afab 8 #include "string.h"
GregC 0:4cf89612afab 9
GregC 0:4cf89612afab 10 /******************************************************************************
GregC 0:4cf89612afab 11 * Input and Output Pinout
GregC 0:4cf89612afab 12 *******************************************************************************/
GregC 0:4cf89612afab 13
GregC 0:4cf89612afab 14 AnalogIn ain(PTB2);
GregC 0:4cf89612afab 15 SSD1351 oled(PTB22,PTB21,PTC13,PTB20,PTE6, PTD15); // SSD1351 OLED Driver (MOSI,SCLK,POWER,CS,RST,DC)
GregC 0:4cf89612afab 16 DigitalOut led1(LED_GREEN);
GregC 0:4cf89612afab 17 Serial pc(USBTX, USBRX);
GregC 0:4cf89612afab 18
GregC 0:4cf89612afab 19 /******************************************************************************
GregC 0:4cf89612afab 20 * Module Variable Definitions
GregC 0:4cf89612afab 21 *******************************************************************************/
GregC 0:4cf89612afab 22
GregC 0:4cf89612afab 23 double ppm; // ppm
GregC 0:4cf89612afab 24
GregC 0:4cf89612afab 25 int value = 0;
GregC 0:4cf89612afab 26 int value_old = 0;
GregC 0:4cf89612afab 27 uint16_t adc_rd;
GregC 0:4cf89612afab 28
GregC 0:4cf89612afab 29 const uint8_t *image1; // Pointer for the image to be displayed
GregC 0:4cf89612afab 30 char text[20]; // Text Buffer for dynamic value displayed
GregC 0:4cf89612afab 31
GregC 0:4cf89612afab 32
GregC 0:4cf89612afab 33
GregC 0:4cf89612afab 34 /**************************************************************************************************
GregC 0:4cf89612afab 35 * Function InitModules()
GregC 0:4cf89612afab 36 * -------------------------------------------------------------------------------------------------
GregC 0:4cf89612afab 37 * Overview:
GregC 0:4cf89612afab 38 * Input: None
GregC 0:4cf89612afab 39 * Output: None
GregC 0:4cf89612afab 40 **************************************************************************************************/
GregC 0:4cf89612afab 41
GregC 0:4cf89612afab 42 void InitModules()
GregC 0:4cf89612afab 43 {
GregC 0:4cf89612afab 44 image1 = AirQuality; // Setting pointer location of the 96 by 96 pixel bitmap
GregC 0:4cf89612afab 45 oled.DrawImage(image1,0,0); // Fill 96px by 96px Screen with 96px by 96px NXP Image starting at x=0,y=0
GregC 0:4cf89612afab 46
GregC 0:4cf89612afab 47 oled_text_properties_t textProperties = {0}; // Get OLED Class Default Text Properties
GregC 0:4cf89612afab 48 oled.GetTextProperties(&textProperties);
GregC 0:4cf89612afab 49
GregC 0:4cf89612afab 50 textProperties.fontColor = COLOR_BLUE; // Set text properties to white and right aligned for the dynamic text
GregC 0:4cf89612afab 51 textProperties.alignParam = OLED_TEXT_ALIGN_LEFT;
GregC 0:4cf89612afab 52 oled.SetTextProperties(&textProperties);
GregC 0:4cf89612afab 53
GregC 0:4cf89612afab 54 strcpy((char *) text,"ppm:"); // Display Legends
GregC 0:4cf89612afab 55 oled.Label((uint8_t *)text,15,75);
GregC 0:4cf89612afab 56
GregC 0:4cf89612afab 57 textProperties.fontColor = COLOR_BLUE; // Set text properties to white and right aligned for the dynamic text
GregC 0:4cf89612afab 58 textProperties.alignParam = OLED_TEXT_ALIGN_RIGHT;
GregC 0:4cf89612afab 59 oled.SetTextProperties(&textProperties);
GregC 0:4cf89612afab 60
GregC 0:4cf89612afab 61 sprintf(text,"%i",value); // Format the value
GregC 0:4cf89612afab 62 oled.TextBox((uint8_t *)text,55,75,20,15); //Increase textbox for more digits
GregC 0:4cf89612afab 63
GregC 0:4cf89612afab 64 /** initialize ADC */
GregC 0:4cf89612afab 65 // ADC0_Init();
GregC 0:4cf89612afab 66
GregC 0:4cf89612afab 67 /** pause for 100ms for ADC module stabilization */
GregC 0:4cf89612afab 68 wait_ms(100);
GregC 0:4cf89612afab 69 }
GregC 0:4cf89612afab 70
GregC 0:4cf89612afab 71
GregC 0:4cf89612afab 72 /**************************************************************************************************
GregC 0:4cf89612afab 73 * Function ReadSensor()
GregC 0:4cf89612afab 74 * -------------------------------------------------------------------------------------------------
GregC 0:4cf89612afab 75 * Overview: Read sensor.
GregC 0:4cf89612afab 76 * Input: None
GregC 0:4cf89612afab 77 * Output: None
GregC 0:4cf89612afab 78 **************************************************************************************************/
GregC 0:4cf89612afab 79
GregC 0:4cf89612afab 80 void ReadSensor()
GregC 0:4cf89612afab 81 {
GregC 0:4cf89612afab 82 adc_rd = ain.read_u16();
GregC 0:4cf89612afab 83 wait_ms(10);
GregC 0:4cf89612afab 84 }
GregC 0:4cf89612afab 85
GregC 0:4cf89612afab 86
GregC 0:4cf89612afab 87 /**************************************************************************************************
GregC 0:4cf89612afab 88 * Function CalculatePPM()
GregC 0:4cf89612afab 89 * -------------------------------------------------------------------------------------------------
GregC 0:4cf89612afab 90 * Overview: Calculation of PPM.
GregC 0:4cf89612afab 91 * Input: None
GregC 0:4cf89612afab 92 * Output: None
GregC 0:4cf89612afab 93 **************************************************************************************************/
GregC 0:4cf89612afab 94
GregC 0:4cf89612afab 95 void CalculatePPM()
GregC 0:4cf89612afab 96 {
GregC 0:4cf89612afab 97 const double Rl = 5000.0; // Rl (Ohm) - Load resistance
daveyclk 1:7b9c19276087 98 const double Vadc_33 = 0.0000503548; // ADC step 3,3V/65535 0.00503mV (16bit ADC)
GregC 0:4cf89612afab 99 double Vrl; // Output voltage
GregC 0:4cf89612afab 100 double Rs; // Rs (Ohm) - Sensor resistance
GregC 0:4cf89612afab 101 double ratio; // Rs/Rl ratio
GregC 0:4cf89612afab 102 double lgPPM;
GregC 0:4cf89612afab 103
GregC 0:4cf89612afab 104 Vrl = (double)adc_rd * Vadc_33; // For 3.3V Vcc use Vadc_33
daveyclk 1:7b9c19276087 105 Rs = Rl * (3.3 - Vrl)/Vrl; // Calculate sensor resistance
GregC 0:4cf89612afab 106 ratio = Rs/Rl; // Calculate ratio
GregC 0:4cf89612afab 107 lgPPM = (log10(ratio) * -0.8) + 0.9; // Calculate ppm
GregC 0:4cf89612afab 108 ppm = pow(10,lgPPM); // Calculate ppm
GregC 0:4cf89612afab 109 }
GregC 0:4cf89612afab 110
GregC 0:4cf89612afab 111
GregC 0:4cf89612afab 112
GregC 0:4cf89612afab 113 /**************************************************************************************************
GregC 0:4cf89612afab 114 * Function DisplayAirQValue()
GregC 0:4cf89612afab 115 * -------------------------------------------------------------------------------------------------
GregC 0:4cf89612afab 116 * Overview:
GregC 0:4cf89612afab 117 * Input: None
GregC 0:4cf89612afab 118 * Output: None
GregC 0:4cf89612afab 119 **************************************************************************************************/
GregC 0:4cf89612afab 120
GregC 0:4cf89612afab 121 void DisplayAirQValue( uint16_t value )
GregC 0:4cf89612afab 122 {
GregC 0:4cf89612afab 123 if (value_old != value)
GregC 0:4cf89612afab 124 {
GregC 0:4cf89612afab 125
GregC 0:4cf89612afab 126 oled_text_properties_t textProperties = {0}; // Get OLED Class Default Text Properties
GregC 0:4cf89612afab 127 oled.GetTextProperties(&textProperties);
GregC 0:4cf89612afab 128
GregC 0:4cf89612afab 129 // clear the previous value
GregC 0:4cf89612afab 130 textProperties.fontColor = COLOR_WHITE; // Set text properties to white and right aligned for the dynamic text
GregC 0:4cf89612afab 131 textProperties.alignParam = OLED_TEXT_ALIGN_RIGHT;
GregC 0:4cf89612afab 132 oled.SetTextProperties(&textProperties);
GregC 0:4cf89612afab 133
GregC 0:4cf89612afab 134 sprintf(text,"%i",value_old); // Format the value
GregC 0:4cf89612afab 135 oled.TextBox((uint8_t *)text,55,75,20,15); //Increase textbox for more digits
GregC 0:4cf89612afab 136
GregC 0:4cf89612afab 137 // display the new value
GregC 0:4cf89612afab 138 textProperties.fontColor = COLOR_WHITE; // Set text properties to white and right aligned for the dynamic text
GregC 0:4cf89612afab 139 textProperties.alignParam = OLED_TEXT_ALIGN_RIGHT;
GregC 0:4cf89612afab 140 oled.SetTextProperties(&textProperties);
GregC 0:4cf89612afab 141
GregC 0:4cf89612afab 142 sprintf(text,"%i",value); // Format the value
GregC 0:4cf89612afab 143 oled.TextBox((uint8_t *)text,55,75,20,15); //Increase textbox for more digits
GregC 0:4cf89612afab 144 }
GregC 0:4cf89612afab 145 value_old = value;
GregC 0:4cf89612afab 146 }
GregC 0:4cf89612afab 147
GregC 0:4cf89612afab 148
GregC 0:4cf89612afab 149 /**************************************************************************************************
GregC 0:4cf89612afab 150 * Function Main()
GregC 0:4cf89612afab 151 * -------------------------------------------------------------------------------------------------
GregC 0:4cf89612afab 152 * Overview:
GregC 0:4cf89612afab 153 * Input: None
GregC 0:4cf89612afab 154 * Output: None
GregC 0:4cf89612afab 155 **************************************************************************************************/
GregC 0:4cf89612afab 156
GregC 0:4cf89612afab 157 int main()
GregC 0:4cf89612afab 158 {
GregC 0:4cf89612afab 159
GregC 0:4cf89612afab 160 InitModules();
GregC 0:4cf89612afab 161
GregC 0:4cf89612afab 162 while (true)
GregC 0:4cf89612afab 163 {
GregC 0:4cf89612afab 164
GregC 0:4cf89612afab 165 ReadSensor();
GregC 0:4cf89612afab 166 pc.printf("Sensor Value 0x%04X\n\r",ain.read_u16());
GregC 0:4cf89612afab 167
GregC 0:4cf89612afab 168 CalculatePPM();
GregC 0:4cf89612afab 169
GregC 0:4cf89612afab 170 DisplayAirQValue(ppm);
GregC 0:4cf89612afab 171
GregC 0:4cf89612afab 172 led1 = !led1;
GregC 0:4cf89612afab 173 Thread::wait(500);
GregC 0:4cf89612afab 174
GregC 0:4cf89612afab 175 }
GregC 0:4cf89612afab 176 }