Flexible 7-segment Driver (SSD)

[sahu77]

Anybody can provide here Flexible 7-segment display driver (SSD) ?
Like provided other Flexible driver in Code Library.
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sahu

[Mike Walne]

I believe there are too many variants on SSD 7-segment displays for this to be feasible.

This looks like yet another rehash of one of your previous posts.

Simply tell us what kind of display you're wanting to drive and maybe someone here will try to help.

Mike

[temtronic]

Hmmm there's only TWO variations of seven segment displays that I know of, IF he's talking about LED types....

1) common anode

2) common cathode

Now if the OP needs MULTIPLE digits..that's another story(he doesn't say), though a 'flexSSD' driver that allowed multiple digits of either, both or mixed types could be useful, and mildly challenging.

hth
jay

[sahu77]

[temtronic]

From a design 'concept', yes, a 'flex' type driver for a 3 digit 7segment LED display is possible. However, from the practical side, it's more trouble than it's worth.
A designer will choose components, like PIC and LED display, cut code based on PIC pin usage, board layout, perhaps connectors, etc.
Time is money, so to get a product to market, you need to decide early what is required and 'get it done'.
To create a 'flex7SSD' driver would be 'something to do on a rainy day instead of playing video games'.

hth
jay

[Ttelmah]

Agreed.

Key to understand is that the core 'driver' is so simple there is nothing to write. All you are doing is putting the required pattern out on the lines controlling the segments, turning on the first digit, then repeating. The lookup tables for the patterns needed have been published many times. The core driver is just a couple of lines. EX_LED.C does exactly this for two digits.

Where it gets 'complex', is first doing the timing in a way to not interfere with other things. The implementation of this will depend totally on what else the system is doing. If there is some nice tick interrupt being used for other things, then this is what should be used, otherwise the implementation will depend on what other timers are being used (CTC, PWM etc.), so becomes 'device specific'.

Then most systems will probably not want to use this many pins, so things like output multiplexor chips will be used, and the complexity comes in driving these, not the display as such. Even for simple use, chips like the 14511, take over the driving of the segments, and make fiddling around with seven lines pointless.

I actually can't imagine that anyone would waste the pins to drive a multi digit 7segment LED directly these days. Something like the MAX7219, will drive up to eight digits, and get rid of the need for all the driver transistors, using just a three PIC pins....

Best Wishes

[sahu77]

I think I'm kidding here as per your comments ?
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sahu