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SPI 4 digit 7 segment displays

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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?

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@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.

post-12741-1351355670_thumb.jpg

post-12741-135135567032_thumb.jpg

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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.

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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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Hey there guys, I ended up picking up 30 of these things.... mainly for no reason :)

 

Although I'm trying to get this working with a bus pirate

 

Does someone have an example to get this working with one? including full setup of the Bus Pirate to displaying some numbers.

I wouldn't mind stacking these things next to eachother for a long display... again for no reason :) just for fun.

 

I went though the setup mode to get to SPI> and tried sending 0x02, 0x40, 0x00, 0x8F but I don't see any numbers lit up.... could I be doing something horribly wrong?

 

Thanks,

--Aaron

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To light up all segments, send: 0x02, 0x40, 0x8F, 0xC0, 0xFF, 0xC2, 0xFF, 0xC4, 0xFF, 0xC6, 0xFF

Also, STB has to be kept low between address and data, you cannot raise it after 0xCx.

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To light up all segments, send: 0x02, 0x40, 0x8F, 0xC0, 0xFF, 0xC2, 0xFF, 0xC4, 0xFF, 0xC6, 0xFF

Also, STB has to be kept low between address and data, you cannot raise it after 0xCx.

 

Hi RobG,

 

If I send anything nothing happens,

The comment you made about keeping STB Low between address and data, is there a way of doing this on the BusPirate?

Only thing that gives this away is the setup option "Clock Polarity" this shows Idle low *Default and Idle High... me thinks Idle High?

 

I'm trying a bunch of different combinations, but I'm a new BusPirate user at least with attempting to decode datasheets... I would think it would be a little easier since some C code was provided above.

 

Thanks,

--Aaron

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Humm, maybe I should stick with an Arduino example sketch if one exists?

 

--Aaron

 

Rob,

I can't get this display to do anything, I'm almost convinced its "My" setup of the buspirate into the SPI mode.

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I don't see anywhere in the code where you specify Pin's to output the clk/strobe/mosi/moso data?

 

This also does not compile in Arduino 1.01 says DISP was not declared in the scope for some reason... but I clearly see it at the beginning.... Its clearly pebcak on my part, but help would be grand!

 

Thanks,

--Aaron

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It kinda barfs on one part of it. in Arduino 1.01

 

sketch_sep24a:2: error: function definition does not declare parameters
sketch_sep24a.ino: In function 'void loop()':
sketch_sep24a:39: error: 'DISP' was not declared in this scope

 

--Aaron

 

Ignore that ^^

There was an = sign that needed to be put on the char line. fixed.

NOnyP.jpg

 

Someone tell me if I'm doing something horribly incorrect as I can't get these displays to do anything.

 

Thanks.

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