wow, thanks a lot
that is just awesome! I'll try to implement it in my project and will let you know how it goes.
thx again for your effort!
Hi,
What about 8 digit display based on 595 chip?
I have found code below -
#define LATCH 12 //pin 12 of BBFuino connect to RCK of 8x7segment module
#define CLOCK 11 //pin 11 of BBFuino connect to SCK of 8x7segment module
#define DATA 10 //pin 10 of BBFuino connect to DIO of 8x7segment module
#define LED 13 //LED is connected to pin 13 of Arduino
#define MultiplexDelay 1 //delay for multiplexing between digit on 8x7segment module
#define LEFT 0 // define the value for left justify
#define RIGHT 1 // define the value for right justify
#define BLANK 11 //array element to make 7segment blank
// array to activate particular digit on the 8x7segment module
// it is the common anode of 7 segment
byte anode[8] = { 0b10000000, //digit 1 from right
0b01000000, //digit 2 from right
0b00100000, //digit 3 from right
0b00010000, //digit 4 from right
0b00001000, //digit 5 from right
0b00000100, //digit 6 from right
0b00000010, //digit 7 from right
0b00000001 //digit 8 from right
};
//array for decimal number, it is the cathode, please refer to the datasheet.
//therefore a logic low will activete the particular segment
//PGFEDCBA, segment on 7 segment, P is the dot
byte cathode[12] = {0b11000000, // 0
0b11111001, // 1
0b10100100, // 2
0b10110000, // 3
0b10011001, // 4
0b10010010, // 5
0b10000010, // 6
0b11111000, // 7
0b10000000, // 8
0b10010000, // 9
0b01111111, //dot
0b11111111 //blank
};
//fucntion to send the serial data out to two 74HC595 serial to parallel shift register and activate the 7 segment.
void display8x7segment(byte datapin, byte clockpin, byte latchpin, byte digit, byte number)
{
digitalWrite(latchpin, LOW);
shiftOut(datapin, clockpin, MSBFIRST, digit); // clears the right display
shiftOut(datapin, clockpin, MSBFIRST, number); // clears the left display
digitalWrite(latchpin, HIGH);
}
//function to display value on 8x7 segment display according to the justify state
void displayNumber8x7segment(byte justify, unsigned long value)
{
byte decimal[8] = {0};
value = value % 100000000; //ensure the value is within 8 digits only
decimal[7] = value / 10000000; //extract digit 7 from value
value = value % 10000000; //extract the rest of 7 digit value
decimal[6] = value / 1000000;
value = value % 1000000;
decimal[5] = value / 100000;
value = value % 100000;
decimal[4] = value / 10000;
value = value % 10000;
decimal[3] = value / 1000;
value = value % 1000;
decimal[2] = value / 100;
value = value % 100;
decimal[1] = value / 10;
decimal[0] = value % 10;
byte zero = 0;
if (justify == RIGHT)
{
for(byte e = 8; e > 0 ; e --)
{
if(zero == 0)
{
if(decimal[e-1] != 0)
{
display8x7segment(DATA, CLOCK, LATCH, anode[e-1], cathode[decimal[e-1]]);
zero = 1;
}
}
else display8x7segment(DATA, CLOCK, LATCH, anode[e-1], cathode[decimal[e-1]]);
delay(MultiplexDelay);
}
}
else //if justify == left
{
byte d = 0;
for(byte e = 8; e > 0; e --)
{
if(zero == 0)
{
if(decimal[e-1] != 0)
{
display8x7segment(DATA, CLOCK, LATCH, anode[7], cathode[decimal[e-1]]);
zero = 1;
d ++;
delay(MultiplexDelay);
}
}
else
{
display8x7segment(DATA, CLOCK, LATCH, anode[7-d], cathode[decimal[e-1]]);
d ++;
delay(MultiplexDelay);
}
}
}
}
void setup() {
pinMode(LATCH, OUTPUT);
pinMode(CLOCK, OUTPUT);
pinMode(DATA, OUTPUT);
pinMode(LED, OUTPUT);
digitalWrite(LATCH, HIGH);
digitalWrite(LED, LOW); //off LED
// set up the LCD's number of columns and rows:
delay(1000); //delay for 1 second
}
void loop(){
//1st demo, 8x7segment will display decimal value from 0 to 9 and dot from 1st digit (most right) until the last digit (most right)
for(byte i = 0; i < 8; i++)
{
for(byte k = 0; k < 11; k++)
{
display8x7segment(DATA, CLOCK, LATCH, anode[i], cathode[k]);
delay(300);
}
}
delay(1000); //delay 1 second
//2nd demo, 8x7segment will display same decimal from 0 to 9 and dot across all 8 digit
for(byte k = 0; k < 11; k++)
{
display8x7segment(DATA, CLOCK, LATCH, 0xff, cathode[k]); //activate all digit
delay(300);
}
delay(1000); //delay 1 second
//3rd demo, 8x7segment will display a decimal value increasing like normal counter.
for (unsigned long value = 0; value < 100000000; value ++)
{
for(byte i = 0; i < 10 ; i ++)
{
displayNumber8x7segment(RIGHT, value); //display the value in right justify format
}
}
delay(1000);
}
I'm trying to get the datasheet but without success. Would you mind to shear it with me?
What a crazy hijack! Not even a mention of what hardware. And then it gets a response! Oy!
Thank you aarg, for your research on this and your code. Here is my small contribution, please excuse my style, these were the first lines that I wrote in this environment. 
It allows one to display a rational number within certain limits
int getFullNumberAndCountDecimals(float fNumber, int* decimals){
*decimals = 0;
float tempNumber = fNumber;
while (tempNumber != trunc(tempNumber)){
tempNumber *= 10;
*decimals+=1;
}
//TODO ignore last digits for numbers that don't fit (like 88.222)
return tempNumber;
}
void printRational(float value){
int countDecimals;
int fullNumber = getFullNumberAndCountDecimals(value, &countDecimals);
modulePrint2(fullNumber,10,testDigits);
testDigits[(numDigits-1)-countDecimals]|= 0x80;
}
One can use it by calling printRational with the desired value.
These last few posts seem completely off topic to me. What are you thinking of?
I think I'll close this thread before someone starts talking about how to cook chickens. 