File content as of revision 1:352a27b3a1ec:

#include "mbed.h"
#include "GUI.h"
#include "mbed_events.h"
#include "ntp-client/NTPClient.h"

#define CY8CKIT_TFT // Light or Temperature?
Thread netTimeThreadHandle;
WiFiInterface *wifi;
#define MBED_CONF_APP_WIFI_SSID "brackenhillc"
#define MBED_CONF_APP_WIFI_PASSWORD "1broches"

/* Reference resistor in series with the thermistor is of 10 KOhm */
#define R_REFERENCE (float)(10000)

/* Beta constant of this thermistor is 3380 Kelvin. See the thermistor
   (NCP18XH103F03RB) data sheet for more details. */
#define B_CONSTANT (float)(3380)

/* Resistance of the thermistor is 10K at 25 degrees C (from data sheet)
   Therefore R0 = 10000 Ohm, and T0 = 298.15 Kelvin, which gives
   R_INFINITY = R0 e^(-B_CONSTANT / T0) = 0.1192855 */
#define R_INFINITY (float)(0.1192855)

/* Zero Kelvin in degree C */
#define ABSOLUTE_ZERO (float)(-273.15)

EventQueue *displayQueue;
Semaphore WiFiSemaphore;
#define SENSOR_BOARD
#ifdef CY8CKIT_TFT
DigitalOut      PwrEnable(P6_2);
#ifdef SENSOR_BOARD
AnalogIn        ALS(P10_7); //Sensor Board
#else
AnalogIn        ALS(P10_0); //TFT Board
#endif
static float lightlevel;
#else
DigitalOut      PwrEnable(P10_0);
DigitalOut      ThermGnd(P10_3);
AnalogIn        Thermistor(P10_1);
static float TempAverage;
#endif
/******************************************************************************************
*
* Display Functions
*
********************************************************************************************/
#define DISP_LEFTMARGIN 10
#define DISP_TOPMARGIN 4
#define DISP_LINESPACE 2
// updateDisplayWiFiStatus
// Used to display the wifi status
void updateDisplayWiFiStatus(char *status)
{
    GUI_SetFont(GUI_FONT_16_1);
    GUI_DispStringAt(status,DISP_LEFTMARGIN, DISP_TOPMARGIN);
    free(status);
}
// updateDisplayWiFiConnectAttempts
// This function displays the number of attempted connections
void updateDisplayWiFiConnectAttempts(int count)
{
    char buffer[128];
    snprintf(buffer,sizeof(buffer),"WiFi Connect Attempts = %d",count);
    GUI_SetFont(GUI_FONT_16_1);
    GUI_DispStringAt(buffer,DISP_LEFTMARGIN, DISP_TOPMARGIN + (GUI_GetFontSizeY()+DISP_LINESPACE) );
}
// updateDisplayNTPFailed
// updates the display with the number of time the NTP Server has been called
// and got a failed response
void updateDisplayNTPFailed(void)
{
    static int count=0;
    char buffer[128];
    count = count + 1;
    snprintf(buffer,sizeof(buffer),"NTP Update Failure = %d\n",count);
    GUI_SetFont(GUI_FONT_16_1);
    GUI_DispStringHCenterAt(buffer,LCD_GetXSize()/2,LCD_GetYSize() - 2*GUI_GetFontSizeY()); // near the bottom
}
// updateDisplayNTPCount
// updates the display with the number of time the NTP Server has been called
void updateDisplayNTPCount(void)
{
    static int count=0;
    char buffer[128];
    count = count + 1;
    snprintf(buffer,sizeof(buffer),"NTP Updates = %d\n",count);
    GUI_SetFont(GUI_FONT_16_1);
    GUI_DispStringHCenterAt(buffer,LCD_GetXSize()/2,LCD_GetYSize() - GUI_GetFontSizeY()); // near the bottom
}
// updateDisplayTime
// This function updates the time on the screen
void updateDisplayTime()
{
    time_t rawtime;
    struct tm * timeinfo;
    char buffer [128];
    time (&rawtime);
    //rawtime = rawtime - (4*60*60); // UTC - 4hours ... serious hack which only works in summer
    rawtime = rawtime + 3600;  // GMT + 1 for BST
    timeinfo = localtime (&rawtime);
    strftime (buffer,sizeof(buffer)," %r ",timeinfo);
    GUI_SetFont(GUI_FONT_32B_1);
    GUI_DispStringHCenterAt(buffer,LCD_GetXSize()/2,LCD_GetYSize()/2 - GUI_GetFontSizeY()/2 - 20);
    printf("%s\r\n", buffer);
    strftime (buffer,sizeof(buffer)," %A   ",timeinfo);
    GUI_SetFont(GUI_FONT_32B_1);
    GUI_DispStringHCenterAt(buffer,LCD_GetXSize()/2,LCD_GetYSize()/2 - GUI_GetFontSizeY()/2 + 20);
    printf("%s\r\n", buffer);
    strftime (buffer,sizeof(buffer)," %D ",timeinfo);
    GUI_SetFont(GUI_FONT_32B_1);
    GUI_DispStringHCenterAt(buffer,LCD_GetXSize()/2,LCD_GetYSize()/2 - GUI_GetFontSizeY()/2 + 60);
    printf("%s\r\n", buffer);
#ifdef CY8CKIT_TFT
    sprintf(buffer, " Light = %d %c  \r\n",int(lightlevel*100), '%');
                            GUI_SetFont(GUI_FONT_32B_1);
    GUI_DispStringHCenterAt(buffer,LCD_GetXSize()/2,LCD_GetYSize()/2 - GUI_GetFontSizeY()/2 - 60);
    printf("%s",buffer);
#else
    float temperature = (B_CONSTANT / (logf((R_REFERENCE / ( 1 / TempAverage - 1 )) / 
                                               R_INFINITY))) + ABSOLUTE_ZERO;

    sprintf(buffer, "Temperature = %d.%1d C\r\n",int(temperature),
                        int((temperature-(int)temperature)*10));
                            GUI_SetFont(GUI_FONT_32B_1);
    GUI_DispStringHCenterAt(buffer,LCD_GetXSize()/2,LCD_GetYSize()/2 - GUI_GetFontSizeY()/2 - 60);
    printf("%s",buffer);
#endif
    printf("%c[4A", 0x1b );
}
void readSensors(){
    PwrEnable = 1;
#ifdef CY8CKIT_TFT
    static int lcount = 0;
    static float Light[8];
    Light[lcount] = ALS;
    lcount = (lcount + 1) & 0x7;
    if (lcount == 0) {
    lightlevel = 0;
        for (int i = 0; i < 8; i++) lightlevel += Light[i];
        lightlevel = lightlevel/8;
#ifdef SENSOR_BOARD
        lightlevel = 1 - lightlevel;
#endif        
#else
    ThermGnd = 0;
    static int lcount = 0;
    static float Therm[8];
    float thermValue;
    float rThermistor;
    thermValue = Thermistor;
    Therm[lcount] = thermValue;
    lcount = (lcount + 1) & 0x7;
    if (lcount == 0) {
        TempAverage = 0;
        for (int i = 0; i < 8; i++) TempAverage += Therm[i];
        TempAverage = TempAverage/8;
/*        rThermistor = (R_REFERENCE/(1 / TempAverage -1 ));
 *       temperature =
 *         (B_CONSTANT / (logf(rThermistor / R_INFINITY))) + ABSOLUTE_ZERO;
 * 
 *       temperature = (B_CONSTANT / (logf((R_REFERENCE / ( 1 / TempAverage - 1 )) / 
 *                                                   R_INFINITY))) + ABSOLUTE_ZERO;
 *
 *        printf("Temp is %d\r\n",(int)(temperature*10));
 *        for (int i = 0; i < 8; i++) 
 *            printf("%d ", (int)(Therm[i]*1000));
 *        printf("therm=%d\r\n", (int)(thermValue*1000));
 */

#endif
    PwrEnable = 0;
   }
}
/******************************************************************************************
* NTPTimeThread
* This thread calls the NTP Timeserver to get the UTC time
* It then updates the time in the RTC
* And it updates the display by adding an event to the display queue
********************************************************************************************/
void NTPTimeThread()
{
    static time_t old_timestamp = 0, timestamp;
    NTPClient ntpclient(wifi);
    while(1) {
        if(wifi->get_connection_status() == NSAPI_STATUS_GLOBAL_UP) {
            timestamp = ntpclient.get_timestamp();
            if (timestamp < old_timestamp) {
                displayQueue->call(updateDisplayNTPFailed);
            } else {
                set_time(timestamp);
                displayQueue->call(updateDisplayNTPCount);
            }
        }
        old_timestamp = timestamp;
        ThisThread::sleep_for(300s); // Goto the NTP server every 5 minutes
    }
}
/******************************************************************************************
*
* Main & WiFi Thread
*
********************************************************************************************/
// wifiStatusCallback
// Changes the display when the wifi status is changed
void wifiStatusCallback(nsapi_event_t status, intptr_t param)
{
    const int buffSize=40;
    char *statusText;
    SocketAddress a;
    statusText = (char *)malloc(buffSize);
    switch(param) {
        case NSAPI_STATUS_LOCAL_UP:
            wifi->get_ip_address(&a);
            snprintf(statusText,buffSize,"WiFi IP = %s",a.get_ip_address());
            break;
        case NSAPI_STATUS_GLOBAL_UP:
            wifi->get_ip_address(&a);
            snprintf(statusText,buffSize,"WiFi IP = %s",a.get_ip_address());
            break;
        case NSAPI_STATUS_DISCONNECTED:
            WiFiSemaphore.release();
            snprintf(statusText,buffSize,"WiFi Disconnected");
            break;
        case NSAPI_STATUS_CONNECTING:
            snprintf(statusText,buffSize,"WiFi Connecting");
            break;
        default:
            snprintf(statusText,buffSize,"Not Supported");
            break;
    }
    displayQueue->call(updateDisplayWiFiStatus,statusText);
}
int main()
{
    int wifiConnectionAttempts;
    int ret;
    GUI_Init();
    printf("%c[2J", 0x1b);   // Clear Screen
    printf("%c[?25l", 0x1b); // Cursor Off
    displayQueue = mbed_event_queue();
    displayQueue->call_every(1s, &updateDisplayTime);
    displayQueue->call_every(100ms, &readSensors);
    wifi = WiFiInterface::get_default_instance();
    wifi->attach(&wifiStatusCallback);

    while(1) {
        wifiConnectionAttempts = 1;
        do {
            ret = wifi->connect(MBED_CONF_APP_WIFI_SSID, MBED_CONF_APP_WIFI_PASSWORD, NSAPI_SECURITY_WPA_WPA2);
            displayQueue->call(updateDisplayWiFiConnectAttempts,wifiConnectionAttempts);
            if (ret != 0) {
                wifiConnectionAttempts += 1;
                ThisThread::sleep_for(2s); // If for some reason it doesnt work wait 2s and try again
            }
        } while(ret !=0);
// If the NTPThread is not running... then start it up
        if(netTimeThreadHandle.get_state() == Thread::Deleted)
            netTimeThreadHandle.start(NTPTimeThread);
        WiFiSemaphore.acquire();
    }
}