I am writing a simple progam to read in temperature and a hall effect sensor. This isnt complicated at all.
It makes use of and LCD. The problem I have is that it runs fine for an hour or 2 and then it needs to be reset because it hangs. For now this isn't a serious problem becuase my use allows me to do this without a worry but this has to be a problem if I expand my use to other purposes I intend to use. I would love some suggestions.
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
int sensorPin = A0; // select the input pin for the potentiometer
int sensorValue = 0; // variable to store the value coming from the sensor
long secs = 0;
int hallPin = A1; // Select the #1 pin for the hall effect sensor
char bufd[16];
char bufe[16];
char *bd;
char *be;
int hallValOld = 0;
int maxHallVal = 0;
int minHallVal = 1023;
void setup() {
// initialize the string string to nothing
bufd[0] = '/0';
bufe[0] = '/0';
bd = bufd;
be = bufe;
// Tell the LCD to turn on.
lcd.begin(16, 2);
}
void loop() {
long modSecs = 0;
double digTemp = 0;
int hallVal = 0;
int digOut = 0;
int dispTemp = 0;
int cTemp = 0;
int hallOut = 0;
bufd[0] = '/0';
bufe[0] = '/0';
digTemp = analogRead(sensorPin);
hallVal = analogRead(hallPin);
digTemp = digTemp/5.2;
dispTemp = digTemp -22;
cTemp = ((digTemp - 54)/1.8);
if (hallVal < minHallVal) {
minHallVal = hallVal;
}
if (maxHallVal < hallVal) {
maxHallVal = hallVal;
}
//sprintf(bd,"Min:%d, Max:%d\n",minHallVal,maxHallVal);
//lcd.print(bd);
lcd.setCursor(0,0);
sprintf(bd,"TempF = %d ",dispTemp);
lcd.print(bd);
lcd.setCursor(0,1);
hallOut = hallVal;
hallOut = hallOut - 515;
sprintf(be,"Gauss = %d ",hallOut);
lcd.print(be);
}
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
int sensorPin = A0; // select the input pin for the potentiometer
int sensorValue = 0; // variable to store the value coming from the sensor
long secs = 0;
int hallPin = A1; // Select the #1 pin for the hall effect sensor
char bufd[16];
char bufe[16];
[glow]char *bd; // Get rid of this. You don't need it.[/glow]
[glow]char *be; // Get rid of this. You don't need it.[/glow]
int hallValOld = 0;
int maxHallVal = 0;
int minHallVal = 1023;
void setup() {
// initialize the string string to nothing
[glow]bufd[0] = '/0'; // Get rid of this. You don't need it. It's not correct; it should be '\0'.[/glow]
[glow]bufe[0] = '/0'; // Get rid of this. You don't need it. It's not correct; it should be '\0'.[/glow]
[glow]bd = bufd; // Get rid of this. You don't need it. [/glow]
[glow]be = bufe; // Get rid of this. You don't need it. [/glow]
// Tell the LCD to turn on.
lcd.begin(16, 2);
}
void loop() {
long modSecs = 0;
double digTemp = 0;
int hallVal = 0;
int digOut = 0;
int dispTemp = 0;
int cTemp = 0;
int hallOut = 0;
[glow]bufd[0] = '/0'; // Get rid of this. You don't need it. [/glow]
[glow]bufe[0] = '/0'; // Get rid of this. You don't need it. [/glow]
digTemp = analogRead(sensorPin);
hallVal = analogRead(hallPin);
digTemp = digTemp/5.2;
dispTemp = digTemp -22;
cTemp = ((digTemp - 54)/1.8);
if (hallVal < minHallVal) {
minHallVal = hallVal;
}
if (maxHallVal < hallVal) {
maxHallVal = hallVal;
}
//sprintf(bd,"Min:%d, Max:%d\n",minHallVal,maxHallVal);
//lcd.print(bd);
lcd.setCursor(0,0);
sprintf([glow]bufd[/glow],"TempF = %d ",dispTemp);
lcd.print([glow]bufd[/glow]);
lcd.setCursor(0,1);
hallOut = hallVal;
hallOut = hallOut - 515;
sprintf([glow]bufe[/glow],"Gauss = %d ",hallOut);
lcd.print([glow]bufe[/glow]);
}
Now to the lock-up...
char bufd[16];
char bufe[16];
You can safely store up to 15 characters in each buffer. Let's look at what you are trying to store...
123456789.1235|
TempF = 0 |
Gauss = 0 |
Looks good so far.
123456789.1235|
TempF = -99 |
Gauss = -99 |
Uh oh. Gauss doesn't fit. Does your application ever get Gauss values below -9? (even it if doesn't, it would be a good idea to both clamp hallOut to an absolute minimum value and make bufe larger)
Let's try another one...
123456789.1235|
TempF = 100 |
Gauss = 100 |
Uh oh. Gauss doesn't fit. Does your application ever get Gauss values above 100? (even it if doesn't, it would be a good idea to both clamp hallOut to an absolute maximum value and make bufe larger)
