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DisplayString() using no delays #14

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DisplayString() using no delays #14

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912f782
DisplayString() using no delays
Feb 7, 2017
f7221ba
fixed decimal point
Feb 11, 2017
855874b
added 'a'
May 13, 2018
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262 changes: 154 additions & 108 deletions src/SevSeg.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -65,7 +65,6 @@ SevSeg::SevSeg()
{
//Initial values
DecAposColon = 0; //This variable tracks the decimal place, apostrophe, and colon (if the display has support)

}
void SevSeg::Begin(boolean mode_in, byte numOfDigits,
byte dig1, byte dig2, byte dig3, byte dig4,
Expand Down Expand Up @@ -152,6 +151,9 @@ void SevSeg::Begin(boolean mode_in, byte numOfDigits,
digitalWrite(segmentApostrophe, SegOff);
pinMode(segmentApostrophe, OUTPUT);
}

previousMicros = 0;
timer = 0;
}

//Begin
Expand All @@ -174,9 +176,12 @@ void SevSeg::Begin(boolean mode_in, byte numOfDigits,
//We need to error check and map the incoming value
void SevSeg::SetBrightness(byte percentBright)
{
//Error check and scale brightnessLevel
if(percentBright > 100) percentBright = 100;
brightnessDelay = map(percentBright, 0, 100, 0, FRAMEPERIOD); //map brightnessDelay to 0 to the max which is framePeriod
//Error check brightnessLevel
if(percentBright > 100){brightness = 100;}
else if(percentBright < 1){brightness = 1;}
else{brightness = percentBright;}

brightnessDelay = (100-brightness)*numberOfDigits*100/brightness;
}


Expand All @@ -189,113 +194,154 @@ void SevSeg::SetBrightness(byte percentBright)
void SevSeg::DisplayString(char* toDisplay, byte DecAposColon)
{
//For the purpose of this code, digit = 1 is the left most digit, digit = 4 is the right most digit
for(byte digit = 1 ; digit < (numberOfDigits+1) ; digit++)
{
switch(digit)
{
case 1:
digitalWrite(digit1, DigitOn);
break;
case 2:
digitalWrite(digit2, DigitOn);
break;
case 3:
digitalWrite(digit3, DigitOn);
break;
case 4:
digitalWrite(digit4, DigitOn);
break;
//This only currently works for 4 digits
}

//Here we access the array of segments
//This could be cleaned up a bit but it works
//displayCharacter(toDisplay[digit-1]); //Now display this digit
// displayArray (defined in SevSeg.h) decides which segments are turned on for each number or symbol
char characterToDisplay = toDisplay[digit-1];
if (characterToDisplay & 0x80) // bit 7 enables bit-per-segment control
{ // Each bit of characterToDisplay turns on a single segment (from A-to-G)
if (characterToDisplay & 0x01) digitalWrite(segmentA, SegOn);
if (characterToDisplay & 0x02) digitalWrite(segmentB, SegOn);
if (characterToDisplay & 0x04) digitalWrite(segmentC, SegOn);
if (characterToDisplay & 0x08) digitalWrite(segmentD, SegOn);
if (characterToDisplay & 0x10) digitalWrite(segmentE, SegOn);
if (characterToDisplay & 0x20) digitalWrite(segmentF, SegOn);
if (characterToDisplay & 0x40) digitalWrite(segmentG, SegOn);
}
else
{
const uint8_t chr = pgm_read_byte(&characterArray[characterToDisplay]);
if (chr & (1<<6)) digitalWrite(segmentA, SegOn);
if (chr & (1<<5)) digitalWrite(segmentB, SegOn);
if (chr & (1<<4)) digitalWrite(segmentC, SegOn);
if (chr & (1<<3)) digitalWrite(segmentD, SegOn);
if (chr & (1<<2)) digitalWrite(segmentE, SegOn);
if (chr & (1<<1)) digitalWrite(segmentF, SegOn);
if (chr & (1<<0)) digitalWrite(segmentG, SegOn);
}
//Service the decimal point, apostrophe and colon
if ((DecAposColon & (1<<(digit-1))) && (digit < 5)) //Test DecAposColon to see if we need to turn on a decimal point
digitalWrite(segmentDP, SegOn);

delayMicroseconds(brightnessDelay + 1); //Display this digit for a fraction of a second (between 1us and 5000us, 500-2000 is pretty good)
//The + 1 is a bit of a hack but it removes the possible zero display (0 causes display to become bright and flickery)
//If you set this too long, the display will start to flicker. Set it to 25000 for some fun.
static byte digit = 0; // to be incremented to cycle through digits
if(micros() - previousMicros > timer)
{
if (digit == numberOfDigits + 1) // meaning the display has a colon or apostrophe
{
turnDigitOff(numberOfDigits);
//After we've gone through the digits, we control the colon and apostrophe (if the display supports it)
//Turn on the colon and/or apostrophe
if ((digitColon != 255) || (digitApostrophe != 255))
{
if (DecAposColon & (1<<4)) //Test to see if we need to turn on the Colon
{
digitalWrite(digitColon, DigitOn);
digitalWrite(segmentColon, SegOn);
}
if (DecAposColon & (1<<5)) //Test DecAposColon to see if we need to turn on Apostrophe
{
digitalWrite(digitApostrophe, DigitOn);
digitalWrite(segmentApostrophe, SegOn);
}
}
digit = 0;
previousMicros = micros();
timer = brightness; //Display this digit for a fraction of a second (between 1us and 5000us, 500-2000 is pretty good)
}

//Turn off all segments
digitalWrite(segmentA, SegOff);
digitalWrite(segmentB, SegOff);
digitalWrite(segmentC, SegOff);
digitalWrite(segmentD, SegOff);
digitalWrite(segmentE, SegOff);
digitalWrite(segmentF, SegOff);
digitalWrite(segmentG, SegOff);
digitalWrite(segmentDP, SegOff);
else if(digit == numberOfDigits)
{
turnDigitOff(numberOfDigits-1);
turnDigitOn(toDisplay, numberOfDigits, DecAposColon);
digit = digitColon != 255 || digitApostrophe != 255 ? digit+1 : 0;
previousMicros = micros();
timer = brightness; //Display this digit for a fraction of a second (between 1us and 5000us, 500-2000 is pretty good)
}

//Turn off this digit
switch(digit)
{
case 1:
digitalWrite(digit1, DigitOff);
break;
case 2:
digitalWrite(digit2, DigitOff);
break;
case 3:
digitalWrite(digit3, DigitOff);
break;
case 4:
digitalWrite(digit4, DigitOff);
break;
//This only currently works for 4 digits
}
// The display is on for microSeconds(brightnessLevel + 1), now turn off for the remainder of the framePeriod
delayMicroseconds(FRAMEPERIOD - brightnessDelay + 1); //the +1 is a hack so that we can never have a delayMicroseconds(0), causes display to flicker
else
{
if (digit == 0)
{
if ((digitColon != 255) || (digitApostrophe != 255))
{
digitalWrite(digitColon, DigitOff);
digitalWrite(segmentColon, SegOff);
digitalWrite(digitApostrophe, DigitOff);
digitalWrite(segmentApostrophe, SegOff);
}
else
{
turnDigitOff(numberOfDigits);
}
// The display is on for microSeconds(brightnessLevel + 1), now turn off for the remainder of the framePeriod
previousMicros = micros();
timer = brightnessDelay;
}
else
{
if (digit != 1)
{
turnDigitOff(digit-1);
}
turnDigitOn(toDisplay, digit, DecAposColon);
previousMicros = micros();
timer = brightness; //Display this digit for a fraction of a second (between 1us and 5000us, 500-2000 is pretty good)
}
digit++;
}
}
}

//After we've gone through the digits, we control the colon and apostrophe (if the display supports it)

//Turn on the colon and/or apostrophe
if ((digitColon != 255) || (digitApostrophe != 255))
{
if (DecAposColon & (1<<4)) //Test to see if we need to turn on the Colon
{
digitalWrite(digitColon, DigitOn);
digitalWrite(segmentColon, SegOn);
}
if (DecAposColon & (1<<5)) //Test DecAposColon to see if we need to turn on Apostrophe
{
digitalWrite(digitApostrophe, DigitOn);
digitalWrite(segmentApostrophe, SegOn);
}
delayMicroseconds(brightnessDelay + 1); //Display this digit for a fraction of a second (between 1us and 5000us, 500-2000 is pretty good)
void SevSeg::turnDigitOff(byte digit)
{
//Turn off all segments
digitalWrite(segmentA, SegOff);
digitalWrite(segmentB, SegOff);
digitalWrite(segmentC, SegOff);
digitalWrite(segmentD, SegOff);
digitalWrite(segmentE, SegOff);
digitalWrite(segmentF, SegOff);
digitalWrite(segmentG, SegOff);
digitalWrite(segmentDP, SegOff);

//Turn off the colon and/or apostrophe
digitalWrite(digitColon, DigitOff);
digitalWrite(segmentColon, SegOff);
digitalWrite(digitApostrophe, DigitOff);
digitalWrite(segmentApostrophe, SegOff);
delayMicroseconds(FRAMEPERIOD - brightnessDelay + 1); //the +1 is a hack so that we can never have a delayMicroseconds(0), causes display to flicker
}

//Turn off this digit
switch(digit)
{
case 1:
digitalWrite(digit1, DigitOff);
break;
case 2:
digitalWrite(digit2, DigitOff);
break;
case 3:
digitalWrite(digit3, DigitOff);
break;
case 4:
digitalWrite(digit4, DigitOff);
break;
//This only currently works for 4 digits
}
}

void SevSeg::turnDigitOn(char* toDisplay, byte digit, byte DecAposColon)
{
switch(digit)
{
case 1:
digitalWrite(digit1, DigitOn);
break;
case 2:
digitalWrite(digit2, DigitOn);
break;
case 3:
digitalWrite(digit3, DigitOn);
break;
case 4:
digitalWrite(digit4, DigitOn);
break;
//This only currently works for 4 digits
}

//Here we access the array of segments
//This could be cleaned up a bit but it works
//displayCharacter(toDisplay[digit-1]); //Now display this digit
// displayArray (defined in SevSeg.h) decides which segments are turned on for each number or symbol
char characterToDisplay = toDisplay[digit-1];
if (characterToDisplay & 0x80) // bit 7 enables bit-per-segment control
{ // Each bit of characterToDisplay turns on a single segment (from A-to-G)
if (characterToDisplay & 0x01) digitalWrite(segmentA, SegOn);
if (characterToDisplay & 0x02) digitalWrite(segmentB, SegOn);
if (characterToDisplay & 0x04) digitalWrite(segmentC, SegOn);
if (characterToDisplay & 0x08) digitalWrite(segmentD, SegOn);
if (characterToDisplay & 0x10) digitalWrite(segmentE, SegOn);
if (characterToDisplay & 0x20) digitalWrite(segmentF, SegOn);
if (characterToDisplay & 0x40) digitalWrite(segmentG, SegOn);
}
else
{
const uint8_t chr = pgm_read_byte(&characterArray[characterToDisplay]);
if (chr & (1<<6)) digitalWrite(segmentA, SegOn);
if (chr & (1<<5)) digitalWrite(segmentB, SegOn);
if (chr & (1<<4)) digitalWrite(segmentC, SegOn);
if (chr & (1<<3)) digitalWrite(segmentD, SegOn);
if (chr & (1<<2)) digitalWrite(segmentE, SegOn);
if (chr & (1<<1)) digitalWrite(segmentF, SegOn);
if (chr & (1<<0)) digitalWrite(segmentG, SegOn);
}
//Service the decimal point
if ((DecAposColon & (1<<(digit-1))) && (digit < 5)) //Test DecAposColon to see if we need to turn on a decimal point
{
digitalWrite(segmentDP, SegOn);
}
}
18 changes: 5 additions & 13 deletions src/SevSeg.h
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Original file line number Diff line number Diff line change
Expand Up @@ -17,17 +17,6 @@

#define BLANK 16 //Special character that turns off all segments (we chose 16 as it is the first spot that has this)

// framePeriod controls the length of time between display refreshes
// It's also closely linked to the brightness setting
#define FRAMEPERIOD 2000
//Total amount of time (in microseconds) for the display frame. 1,000us is roughly 1000Hz update rate
//A framePeriod of:
//5000 is flickery
//3000 has good low brightness vs full brightness
//2000 works well
//500 seems like the low brightness is pretty bright, not great


//This is the combined array that contains all the segment configurations for many different characters and symbols
const uint8_t characterArray[] PROGMEM = {
// ABCDEFG Segments 7-segment map:
Expand Down Expand Up @@ -128,7 +117,7 @@ const uint8_t characterArray[] PROGMEM = {
0b0000000, // 94 '^' NO DISPLAY
0b0001000, // 95 '_'
0b0000010, // 96 '`'
0b1110111, // 97 'a' SAME AS CAP
0b1111101, // 97 'a'
0b0011111, // 98 'b' SAME AS CAP
0b0001101, // 99 'c'
0b0111101, // 100 'd' SAME AS CAP
Expand Down Expand Up @@ -180,6 +169,8 @@ class SevSeg {
//Private Functions
void displayCharacter(byte characterToDisplay); //Illuminates the correct segments
void SplitNumber(int);
void turnDigitOff(byte digit);
void turnDigitOn(char* toDisplay, byte digit, byte DecAposColon);

//Private Variables
boolean mode, DigitOn, DigitOff, SegOn, SegOff;
Expand All @@ -190,7 +181,8 @@ class SevSeg {

byte numberOfDigits;

unsigned int brightnessDelay;
unsigned int brightness, brightnessDelay;
unsigned long previousMicros, timer;

byte DigitPins[4];
byte SegmentPins[8];
Expand Down