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Topic: 3bit Common Anode Digital Tube 0.36in. red LED - help please (Read 975 times) previous topic - next topic


Jan 15, 2013, 09:23 pm Last Edit: Jan 15, 2013, 11:03 pm by Ruffsta Reason: 1
ok, just received this in the mail...

looking for help on this one as well, however - with this one after it's hooked up and working.. i'll eventually want to to hook up 2 buttons to it - (one that will move the digits up and another for down). once working with the buttons it will start off wit "SEL" or blinking "---", then once the user hits the up button it will start with "A01" and every time it will count up to "J10".. and each time the user hits down, it will count down to "A10"

A01 - A10, B01 - B10, and so on until J10 - once at "J10" it will not count up anymore, but start at "A01" again and same with the opposite button.. once at "A01" start back at "J10".

i'll assume this will have some sort of val or state condition.. i'll write the whole code, if someone could just get me stared..

any schematics on this one for starters?

thanks in advance


Jan 16, 2013, 12:01 am Last Edit: Jan 16, 2013, 12:51 am by Msquare Reason: 1
Schematics : You ordered it, so you probably have a type number or something. Then use Google. To assist with schematics we need to know the pinout.

There are Binary-7Seg converter chips that include multiplexing (your display has 11 pins and 24 segments and dots - so there must be some multiplexing). That may be simpler than trying to do it all in software in the Arduino (depends if you are better at hardware or software).

To get started on the code just write a sketch that reads your two buttons and uses Serial.print to write the A01 A02 and so on. Hints: you will need two counters. When counter one goes to 11, reset it to 1 and increment the other on to "2" (which you display as a "B")


Most likely it is made like this
So you need 3 PNP transistors to source current, and a shift register like TPIC6B595 to sink current from the cathode resistors.

Setup the data for digit 1, turn on its PNP. After 8mS, turn it off.
Setup the data for digit 2, turn on its PNP. After 8mS, turn it off.
Setup the data for digit 3, turn on its PNP. After 8mS, turn it off.

Use millis capture & subtraction to see when time has elapsed:
Code: [Select]

current_time = millis();
if ((current_time - previous_time) >= interval) {
previous_time = previous_time + interval; // set up for next pass
keep track of which digit in array
digitalWrite(pnpArray[pnpPin]; // pnpPin[2,3,4] example for the 3 pins being used
use an array to send out the font data
use SPI to send data to the shift register:
digitalWrite(shift_reg_latch, LOW);
digitalWrite(shift_reg_latch, HIGH);

Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
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Jan 16, 2013, 05:39 am Last Edit: Jan 16, 2013, 05:44 am by Ruffsta Reason: 1
the only shift resistors i have at the moment are: SN74HC595N 74HC595 8-Bit Shift Register DIP-16 IC

and the only pnp's i have are:
2N3906 TO-92 General Propose PNP Transistor are the only pnp's i have


the seller linked me to this image if it helps any..

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