main.cpp

00001 #include "mbed.h"
00002 #include "EthernetNetIf.h" // ethernet 
00003 #include "NTPClient.h" // Network Time Protocol client
00004 
00005 // rudimentary driving of a 20T202DA2JA vacuum fluorescent display, 20 chars x 2 lines
00006 // display has 5 pins
00007 // 1 - green - GND
00008 // 2 - yellow - Vcc
00009 // 3 - orange - SIO - serial data - MOSI - p5
00010 // 4 - red - /STB - active low device select - p10
00011 // 5 - brown - SCK - serial clock - sclk - p7
00012 
00013 // Also, I have fitted a battery on my breadboard to the RTC, to keep the time across power downs.
00014 
00015 // VFD
00016 SPI spi(p5, p6, p7); // mosi, miso, sclk (miso not used by display)
00017 DigitalOut cs(p10); // chip select (active low)
00018 
00019 // alternatively, look on the ethernet interface to find an NTP server and set the time from that.
00020 EthernetNetIf eth; // instantiate an ethernet connection
00021 NTPClient ntp; // instantiate an NTP client
00022 
00023 // summertime
00024 int summertime = true; // if this is true, then it's summer!
00025 
00026 void DATA(unsigned char displaying) {
00027     // Select the device by setting chip select low
00028     cs = 0;
00029     spi.write(0xfa);
00030     spi.write(displaying);
00031     // Deselect the device
00032     cs = 1;
00033 }
00034 
00035 void COM(unsigned char telling) {
00036     // Select the device by setting chip select low
00037     cs = 0;
00038     spi.write(0xf8);
00039     spi.write(telling);
00040     // Deselect the device
00041     cs = 1;
00042 }
00043 
00044 int i = 0; // initalise the character steppers
00045 
00046 void INITIALISE_DISPLAY() {
00047     COM(0x01); //clear all display and set DD-RAM address 0 in address counter
00048     COM(0x02); //move cursor to the original position
00049     COM(0x06); //set the cursor direction increment and cursor shift enabled
00050     COM(0x38); //set 8bit operation,2 line display and 100% brightness level
00051     COM(0x80); //set cursor to the first position of 1st line
00052     COM(0x0c); //set display on,cursor on,blinking off
00053 }
00054 
00055 void printVFDLine1(char statusString[21]) {
00056     COM(0x80); // first line
00057     for (i=0; i<20; i++) {
00058         DATA(statusString[i]); // step through the top line
00059     }
00060 }
00061 
00062 void printVFDLine2(char statusString[21]) {
00063     COM(0xc0); // second line
00064     for (i=0; i<20; i++) {
00065         DATA(statusString[i]); // step through the first part of the bottom line
00066     }
00067 }
00068 
00069 char timeStringTop[21]; // used with the NTP code in the first line display code
00070 char timeStringBottom[21]; // used with the NTP code in the second line display code
00071 char statusString[41]; // place to put startup status text, etc
00072 
00073 int main() {
00074     // Setup the spi for 8 bit data, high steady state clock,
00075     // second edge capture, with a 1MHz clock rate
00076     spi.format(8,3); // set SPI mode
00077     spi.frequency(1000000);
00078 
00079     // Ethernet and NTP stuff begins (from http://mbed.org/cookbook/NTP-Client )
00080     INITIALISE_DISPLAY();
00081     char statusString1[21] = "Start               ";
00082     printVFDLine1(statusString1);
00083     char statusString2[21] = "Setting up...       ";
00084     printVFDLine2(statusString2);
00085 
00086     EthernetErr ethErr = eth.setup();
00087     if (ethErr) {
00088         printf("Error %d in setup.\n\r", ethErr);
00089 
00090         char statusString3[21] = "Error %d in setup.\n\r";
00091         printVFDLine1(statusString3);
00092         return -1;
00093     }
00094 
00095     Host server(IpAddr(), 123, "0.uk.pool.ntp.org");
00096     ntp.setTime(server);
00097 
00098     char statusString4[21] = "0.uk.pool.ntp.org   ";
00099     printVFDLine1(statusString4);
00100     char statusString5[21] = "Setup OK            ";
00101     printVFDLine2(statusString5);
00102 
00103     // end of Ethernet and NTP stuff
00104 
00105     INITIALISE_DISPLAY(); // call the function that initialises the VFD
00106 
00107     while (1) {
00108 
00109         time_t rtc_seconds = time(NULL); // somehow gets the current amount of seconds, evah!
00110 
00111         if (summertime) { // if the summertime variable is true, we add 3600 seconds to rtc_seconds
00112             rtc_seconds = rtc_seconds + 3600;
00113         }
00114 
00115         // build the two lines of the display separately
00116         strftime(timeStringTop, 21, "%a %d %b %T ", localtime(&rtc_seconds)); // put the hours:minutes:seconds, then full day, then am/pm
00117         printVFDLine1(timeStringTop);
00118 
00119         //  char thingStringBottom[21] = "This is a blank line";
00120         //  printVFDLine2(thingStringBottom);
00121 
00122         wait(1);
00123 
00124     }
00125 
00126 }