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SPI 4 digit 7 segment displays


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#1 touch

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Posted 13 September 2012 - 04:30 AM

I found these on eBay and bought some:
http://www.ebay.com/... ... 0807998835

They are 7 segment displays with the PT6961 driver chip built in. Datasheet here: http://www.princeton... ... PT6961.pdf

I cant seem to find anything out about the Oasis display, it appears to be pretty old with a date code of 0726, I'd assume the 26th week of 07. I did figure out the pinout of the display though. IC requires between 3.3 and 5v so I assume it will work with the launchpad.

Hope to get this working soon, I'll update when I do...
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#2 cde

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Posted 13 September 2012 - 07:46 AM

2 color, 4 digit + separator displays for 1.30 each? Nice. Hows the color working though?

#3 RobG

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Posted 13 September 2012 - 11:55 AM

I don't need 10, but I could use few of them. Is anyone interested in splitting it? PM me if you are.

#4 touch

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Posted 14 September 2012 - 12:25 AM

Pin out is as follows, starting from the pin closest to PIN1 on the SOP32 chip.
VCC, STB, CLK, DIN, DOUT, GND.

For SPI, clock polarity needs to be set to 1 and phase 0, LSB, I believe.

I've not gotten anything meaningful displayed yet.. I'm still trying to decipher the datasheet and figure out the address's for each digit/segment.

I've never seen a 7 segment display with different colors like this one.
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#5 cde

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Posted 14 September 2012 - 01:50 AM

Is the middle divider the only red leds?

#6 touch

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Posted 14 September 2012 - 05:13 AM

From what I can tell so far the decimal points aren't hooked up at all. :cry:

It seems that way, green digits with a red colon...very odd.

I noticed they have another set of displays here:
http://www.ebay.com/... ... 2ec116e572

Seems they are the same P/N though. I'm almost tempted to buy another 10... No idea what I'd use them for but I've never seen any displays like these with the driver chip built in, let alone at this price...

Here's what it looks like after I mapped out the segments.
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#7 JWoodrell

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Posted 14 September 2012 - 12:12 PM

http://www.oasistek.... ... 65CB-B.pdf

Here is the datasheet for the Led display itself, but they dont have anything on their site about the "d" version with the driver chip, so it may be custom for someone... Hope this helps
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#8 cubeberg

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Posted 14 September 2012 - 02:51 PM

Are you turning both the red and blue on? The auction was listed as red & blue.
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#9 touch

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Posted 15 September 2012 - 12:49 AM

Nice find on the datasheet, I've been looking for one with no luck so far. I'm going to try to contact the manufacturer and see if I can get them to send me one.

From what I can tell there are not two segment colors, I'm not sure why the auction says that, maybe an error?

The digits are mapped as the following bits for each corresponding segment, LSB:
0 - A
1 - B
2 - C
3 - D
4 - E
5 - F
6 - G
7 - Colon

DP Appears to be unconnected from what I can tell. I filled the entire display RAM with FF and can't get them to light.

#10 cde

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Posted 15 September 2012 - 01:05 AM

Considering they have multiple auctions, your's listed as red+blue (but you got green + maybe red?) and they have a different auction for red only on the same type of displays, but it looks like they have the same part numbers? Is there any other markings on the display itself?

#11 touch

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Posted 15 September 2012 - 01:29 AM

Here's what the label on the tube they came in says:
PN 07G024002500
SPEC: 4/D LED DISPLAY BLUE+RED
TOFD-5465GGH-B
Date Code: 0726 Lot code DB02
Maker OASIS Vender OASIS

Display has the same marking TOFD-5465GGH-B on it.

Here's some code I wrote in Energia to cycle through the display:
#include <SPI.h>

const int slaveSelectPin = SS;
const char DISP[16] {0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07, 0x7f, 0x6f, 0x77, 0x7c, 0x58, 0x5e, 0x79, 0x71};

void setup() {
  pinMode (slaveSelectPin, OUTPUT);
  SPI.begin(); 
  SPI.setBitOrder(LSBFIRST); 
  SPI.setDataMode(SPI_MODE2);
}

void loop() {
  //set display to 6x12 segments
  digitalWrite(slaveSelectPin,LOW);
  SPI.transfer(0x02);
  digitalWrite(slaveSelectPin,HIGH); 
  
  //set to writing mode, auto incrament address after data write
  digitalWrite(slaveSelectPin,LOW);
  SPI.transfer(0x40);
  digitalWrite(slaveSelectPin,HIGH);
  
  //first clear 8 bytes of the display RAM
  digitalWrite(slaveSelectPin,LOW);
  SPI.transfer(0xC0);
  for(int i=0; i<8; i++){
      SPI.transfer(0x00);
  }
  digitalWrite(slaveSelectPin,HIGH); 
  
  //display on, max brightness
  digitalWrite(slaveSelectPin,LOW);
  SPI.transfer(0x8F);
  digitalWrite(slaveSelectPin,HIGH); 
  
  //count through 0-9,a-f
  for(int i=0; i<16; i++){
      digitalWrite(slaveSelectPin,LOW);
      SPI.transfer(0xC0);
      SPI.transfer(DISP[i]);
      digitalWrite(slaveSelectPin,HIGH); 
      delay(500);
  }
}


#12 RobG

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Posted 17 September 2012 - 10:13 PM

OK, got mine, they are green with red colon, not sure what BLUE + RED mean (maybe that's why they ended up with the surplus guy :) )
In any case, thanks for finding them touch, they are awesome.

Here's my test code
#include <msp430g2231.h>

void sendData(unsigned char data, unsigned char hold);
const char segments[16] = { 0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07, 0x7f,
		0x6f, 0x77, 0x7c, 0x58, 0x5e, 0x79, 0x71 };

void main(void) {
	WDTCTL = WDTPW + WDTHOLD; // stop WDT

	P1OUT |= BIT0 + BIT5 + BIT6;
	P1DIR |= BIT0 + BIT5 + BIT6;

	sendData(0x02, 0);
	sendData(0x40, 0);
	sendData(0x8F, 0);

	char i = 0;
	char colon = 1;
	while (1) {
		for (i = 0; i < 16; i++) {
			colon ^= 0x01;
			sendData(0xC0, 1);
			sendData(segments[i] + (colon ? BIT7 : 0), 0);
			sendData(0xC2, 1);
			sendData(segments[i] + (colon ? BIT7 : 0), 0);
			sendData(0xC4, 1);
			sendData(segments[i], 0);
			sendData(0xC6, 1);
			sendData(segments[i], 0);
			_delay_cycles(500000);
		}
	}
}

void sendData(unsigned char data, unsigned char hold) {
	char c = 0;
	P1OUT &= ~BIT0;
	while (c < 8) {
		(data & 0x01) ? (P1OUT |= BIT6) : (P1OUT &= ~BIT6);
		data >>= 1;
		P1OUT &= ~BIT5;
		P1OUT |= BIT5;
		c++;
	}

	if (!hold) {
		P1OUT |= BIT0;
	}
}

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#13 touch

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Posted 17 September 2012 - 11:26 PM

OK, got mine, they are green with red colon, not sure what BLUE + RED mean (maybe that's why they ended up with the surplus guy :) )
In any case, thanks for finding them touch, they are awesome.

You're welcome, they are awesome! I wish I could find some with working decimal points, or maybe a 6 digit version, but this is the first time I've ever found a 7 segment display with a driver IC built in. Sure beats having to deal with current limiting resistors/pwm + multiplexing...

It's kinda funny, since I made this post they've sold 30+, but when I bought mine they had sold none.

#14 cde

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Posted 18 September 2012 - 04:51 AM

This thread has been seen almost 500 times, and they featured it on the 43oh blog.

Also, Oasis's online catalog shows that the 5425 lcd's raw pinout. 1 common for each 4 digits, with 7 segment lines. But the last two commons have an extra segment for the separator dots. The decimal points are not connected at all, and probably don't even have leds in the positions.
http://issuu.com/oas...splay_catalogue

#15 JWoodrell

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Posted 21 September 2012 - 12:53 AM

in answering the question of whether there are decimal LED's buried in there somewhere I can conclusively say no there are not.

I sacrificed one to the gods of tearing stuff apart and found there are neither LED's or driving circuit pads for them, just the 4 7 segment characters and the two colon points.

it was interesting extricating the circuit board without breaking it (although the LED's get destroyed when you split the two halves apart)

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#16 RobG

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Posted 21 September 2012 - 02:25 AM

Can you salvage IC?

#17 touch

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Posted 21 September 2012 - 04:12 AM

I was considering adding my own LED's for the DP's on things where I needed them. It's easy enough to solder to the chip, just lightly sand the epoxy off of the chip legs, drill a hole where the DP is and stickin a 0402 LED with some enameled wire connecting it to the driver chip.

Can you tell if there are any traces in the way of doing this?

#18 JWoodrell

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Posted 21 September 2012 - 05:03 AM

@touch - the first and fourth decimal place would be clear to drill through to mount a led in, the second one is blocked by the 6 interface pins, and the third is blocked by a via.

@RobG - challenge complete... :) There is still some epoxy on the inside of the legs but it wouldn't interfere with reusing the chip, and if i tried too aggressively to clean it off, i would probably damage the legs.

I actually salvaged the little SMD resistor as well, but it is tiny and i misplaced it, now I can't find the thing :( the capacitor could have been salvaged if I was paying closer attention to it.

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#19 cde

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Posted 21 September 2012 - 05:48 AM

1st and 4th? that's all most people would need. Drill in from the back, a little at a time, drop down the led, test to see if it lights decently enough, drill some more if needed (jewelers drill [or hex shank drill bit on screwdriver] is probably best).

As for the legs, look into ic decapping acid. Just enough to clean them without tools. There are some cheap homebrew versions.

#20 JWoodrell

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Posted 21 September 2012 - 12:32 PM

The other option that would allow all 4 LEDs would be to drill into the side of the case, you have a good bit of room above the pcb that is just clear plastic(about 3/16 if i had to guess based on memory) you could drop the led in the side. Just a thought, when i get back home ill measure and take pictures
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