Thanks for the tips guys.
This is the code to drive a large 7 segment LED clock.
There are 4 buttons for setting and mode purposes.
If the clock setting button is pressed, the clock enters setting mode, where 12 digits are displayed on the LED to show the time.
As it stands now, the program enters "display" mode, if no keys on the hardware or no keys on the serial terminal are pressed. Then it starts to spit out a string parsed off the RTC in a timer interrupt function parsing it into a string "DispDigits"
In run mode, a variable for the serial port, Settingdigits is assigned to DispDigits, in setting mode, DispDigits is assigned to Settingdigits.
Corruption happens in the final loop
while (true)
{wait(1.0);
pc.printf("Time Is %s \r\n",SettingDigits.c_str());
} //end while loop.
When "Time is" becomes replaced by garbage from the upper half of the ascii codemap
#include "mbed.h"
#include "DebouncedIn.h"
#include "string.h"
#include "string"
#include "stdio.h"
#include "stdlib.h"
///define SPI for displays
SPI spi(p11, p12, p13); // mosi, miso, sclk
//spi.format (8,0);
DigitalOut Latch(p14);
DigitalOut OE (p15);
//Every 8th bit is a decimal point
DebouncedIn button1 (p30); //buttons debounced by DebouncedIn.h
DebouncedIn button2 (p29);
DebouncedIn button3 (p28);
DebouncedIn button4 (p27);
DigitalOut led1(LED1);
DigitalOut led2(LED2);
DigitalOut led3(LED3);
DigitalOut led4(LED4);
Ticker Tsystem, TTimeout;
int dispblink; //blinking character counter.
// time units.
//char seconds,minutes,hours,day,month,year;
//Define character map for LED.
const char Seg7[11] = {0,1,2,4,8,16,32,64,128,128,128}; //0..9 are digits and 10= space
bool blink[12] ;
char spidata[12];
char Sec_dp; //which bit in the SPI needs to be on.
string DispDigits,NewDigits,SettingDigits ;
int charpos,charctr;
int Display_mode,setctr;
//modeconstants
int leadsuppress=1;
int flashingseconds=2;
int clocksetting=4;
//timers
bool timedout, resettimeout;
bool waiting;
int waitctr,timingctr,Mychar;
//clock structures
struct tm Clocktime;
time_t Clocksecs;
void timerout ()
{ if (resettimeout) {timingctr=10;resettimeout=false;};
timingctr--;
if (timingctr==0) {timedout=true;} else {timedout=false;};
};
void DisplayMonitor()
// Every 1/8 second, check to see if display needs to be updated
{char chardata;
if (dispblink>7) { //reset blinking timer
waiting=false;
dispblink=0;}
else dispblink++;
if ((Display_mode & clocksetting) == 0) { //Get RTC time into a datastructure.
//read rtc into TM
Clocksecs=time (NULL);
led1=!led1;
char buffer[12];
strftime(buffer, 12, "%I%m%S%d%m%y", localtime(&Clocksecs));
DispDigits=buffer;
SettingDigits=DispDigits;
} else {DispDigits=SettingDigits;};
//Disp digits now has blanking/blinking sorted out
//Build SPI data for tranmission.
NewDigits=DispDigits;
for (charctr =0; charctr<=12; charctr++) {
if (dispblink>4) {
if (blink[charctr]==true) {
NewDigits[charctr]=10;} else {NewDigits[charctr]=DispDigits[charctr];}; //Blank character temporarily
int Ord;
Ord = int (NewDigits[charctr]) - int ('0');
chardata = Seg7 [Ord];
if (Display_mode && flashingseconds) {
Sec_dp=atoi(NewDigits.substr(4,2).c_str()) % 60;
if (charctr==Sec_dp) {
chardata=chardata | 8;} else {chardata=chardata & 0x11110111;}; // with whatever to mask on second DP 8 might be wrong
spidata[charctr]=chardata;
};
};
//clock out the prepared data.
Latch=false;
OE=false;
for (charctr =0;charctr<=12; charctr++) {
spi.write(spidata[charctr]);
};
Latch=true;
OE=true;
};
}; //end of display monitor
int main(){
Tsystem.attach (DisplayMonitor,0.125);
TTimeout.attach (timerout,1.0);
Serial pc(USBTX, USBRX); // tx, rx
pc.printf("Hello Clock 5.00 \n\r");
timedout=false;
Display_mode=0;
DispDigits =' ';
NewDigits =' ';
wait(1);
if (pc.readable() ) {Mychar=pc.getc();};
//check buttons are pressed
if ((button3.read() ==true) | (Mychar=='l'))
{Display_mode=Display_mode+leadsuppress;};
if ((button4.read() ==true) | (Mychar=='f'))
{Display_mode=Display_mode+flashingseconds;};
if ((button1.read() == true) | (Mychar=='c'))
{Display_mode=Display_mode+clocksetting;};
pc.printf("Got Mode\n\r");
Display_mode=clocksetting;
//if button pressed enter setting mode
//freeze display with current time.
if ( ( button1.read() ==true ) || (Display_mode == clocksetting)) {
//wait for mode setting button to be released
pc.printf("In setting mode\n\r");
setctr='0';
charpos=0;
SettingDigits="000000000000";
resettimeout=true;
waiting=false;
while (timedout== false) {
//In setting mode
Mychar=0;
if (pc.readable() ) {Mychar=pc.getc();};
if ( ((button1.read()==true) & (button2.read()==false)) | (Mychar=='.' ))
{resettimeout=true;
if (charpos < 12)
{charpos++;if (charpos==4) charpos=6;} //skip seconds on way up
else charpos=0;setctr=NewDigits[charpos];};
if ( ((button2.read()==true) & (button1.read()==false)) | (Mychar==',' ))
{resettimeout=true;
if (charpos > 0)
{charpos--; if (charpos==5) charpos=3;} //Skip Seconds on the way DOWN
else charpos=12;setctr=NewDigits[charpos];};
if ( ((button3.read()==true) & (button4.read()==false)) | (Mychar=='[' )) {resettimeout=true; if (setctr<'9') setctr++;else setctr='0';};
if ( ((button4.read()==true) & (button3.read()==false)) | (Mychar==']' )) {resettimeout=true; if (setctr>'0') setctr--;else setctr='9';};
SettingDigits[charpos]=setctr;
pc.printf("Charpos Setctr %d %s \r\n",charpos, SettingDigits.c_str());
blink[charpos]=true;
//Add key delay, so the display doesn't scroll too fast.
wait(0.25);
}
pc.printf("Finished Setting:Set RTC %s \n\r",SettingDigits.c_str());
// As we exit setting mode, adjust RTC to read new time.
Clocktime.tm_hour = atoi (SettingDigits.substr(0,2).c_str());
Clocktime.tm_sec = int (0);
Clocktime.tm_min = atoi (SettingDigits.substr(2,2).c_str());
Clocktime.tm_mday = atoi (SettingDigits.substr(6,2).c_str());
Clocktime.tm_mon = atoi (SettingDigits.substr(8,2).c_str())+1;
Clocktime.tm_year = atoi (SettingDigits.substr(10,3).c_str())+100;
pc.printf ("Tm_hour %d \r\n",Clocktime.tm_hour);
pc.printf ("Tm_Min %d \r\n",Clocktime.tm_min);
pc.printf ("Tm_sec %d \r\n",Clocktime.tm_sec);
pc.printf ("Tm_mday %d \r\n",Clocktime.tm_mday);
pc.printf ("Tm_mon %d \r\n",Clocktime.tm_mon);
pc.printf ("Tm_year %d \r\n",Clocktime.tm_year);
set_time(mktime(&Clocktime));
pc.printf("Parsed clock into RTC ");
}; //end setting mode
pc.printf("In Clock Mode\n\r");
// Display_mode=Display_mode || 0x111110111; //turn off clock setting mode
Display_mode=0;
while (true)
{wait(1);
pc.printf("Time Is %s \r\n",SettingDigits.c_str());
} //end while loop.
}; // end program
Adam Green.
12
replies
Ad van der Weiden wrote:
I'm having a problem using printf via serial USB to PC.
For the first few cycles through my code, the output of a "printf" statement is fine, after about 30 seconds, the constant part of the statement becomes corrupted, and even a reset of the board doesn't restore normal function. The variable part of the statement stays properly formatted though !!
Powering down and restarting DOES restore the printf, but again it corrupts permanently after a few more seconds.
I'd be grateful for suggestions about what to look for !
There is an interrupt routine running, but the routine has no printing in it.
Thanks a lot.
Steve