Author Topic: 7-segments diplay with 14543  (Read 4254 times)

arma61

7-segments diplay with 14543
« on: November 11, 2008, 11:03:25 AM »
Hi

pls help me with this idea, I have a Korg Pandora multieffect, I've already took out 3 wires and connected to 2 pushbuttons, so I can change programs with my foot; the fx is on the pedalboard on the ground. What I would like to build is a display that change number from 1 to 9 (I'm only using 9 pre-set programs) when I push the button to change the programs on the fx.

I've seen an MC14543B capable to driver a 7-segment display, while I can understand how it works, through the "Truth Table", I cannot figure out how to /where feed it so it can feed the display.

Is this doable? did someone of you already have a schema I can start from. I don't care if, when pedalboard's power is off, the counter gets reset while the fx will remain on the programs, I thought I can have another pushbotton to increase the number on the display so to match the one on the fx.

Sorry if it's a little bit weird, hard to explain that in English !

Thanks 4 help
Ciao
Armando

"it's a matter of objectives. If you don't know where you want to go, any direction is about as good as any other." R.G. Keen

The Tone God

Re: 7-segments diplay with 14543
« Reply #1 on: November 11, 2008, 02:38:49 PM »
It is doable. The 14535 converts a 4-bit input to an output that can drive a 7 seg display. You hook up the 14535 four inputs to your controller and have the controller generate an output that corresponds to the datasheet. As you go through your programs you set the four outputs to the number needed.

Andrew

arma61

Re: 7-segments diplay with 14543
« Reply #2 on: November 12, 2008, 09:21:30 AM »
Thx Andrew but how do you say this in an easy way??  :icon_lol: :icon_lol:

I think I've misguided you saying "while I can understand how it works, through the Truth Table, " indeed what I've understood is just a little bit, like if you feed with 0 the pins 4-2-3 and with 1 pin 5 (C) then segments connected at pins b and c gets light and show number 1. That's all I know (is it right btw?)

So how do I "have the controller generate an output that corresponds to the datasheet", what is "the controller", which chip shall I use?

Also, I didn't say this on previous post, I would like also the possibility to change number from 9 to 1.

is it getting too complex?, I mean for me, as, obviously, I don't want you guys to do the whole job for me, I'm also thinking about the making of the PCB, should it turn out to be too coplex to do it "at home" ?

Should I try to look for a kit ?

Thx
Armando
"it's a matter of objectives. If you don't know where you want to go, any direction is about as good as any other." R.G. Keen

The Tone God

Re: 7-segments diplay with 14543
« Reply #3 on: November 13, 2008, 02:28:05 PM »
Ah now I understand. I took a look at what you are modifying and I think I am going to have to restate that this is going to be more difficult then I thought. The unit has a custom display. Trying to connect to it and making sure the digit you are displaying matches the unit's setting is going to be difficult. To do this will take more then just connecting a few wires.

Andrew

arma61

Re: 7-segments diplay with 14543
« Reply #4 on: November 13, 2008, 05:29:43 PM »
thx Adrew, in deed my idea wasn't to connect to the FX display but just connected the counter in parallel with with its +/- buttons

(ahh it's very difficult for me to explain it in English ;) ) it should be in this way


The Pandora already have 3 wire coming out that I've soldered to the PCB (SMD so it was very hard!), one "common", one for program-up and one for down, they are connected to 2 pushbuttons, so I can still push the +/- button already present on the Pandora or I can push my new 2 pushbuttons. My idea was to make a counter able to count up and down from 0 to 9, connect it in parallel with my added 2 pushbuttons so when I push the + or - (either on the FX or my new ones) the display change the numbers. I know I'll have problem when I switch off the power as the fx will remain on the program chosen and the counter will (probably) reset to 0, but I can live with that.

Anyway I saw now different IC I an use, like CD4510 and CD4511, if I understand them one is counting up or down and the other one is driving the 7-segment display, still need to understand how the whole thing should work, I'll keep on trying though

I've found on Internet some up/down counter like the "9 Second Digital Readout Countdown Timer" on this link (towards the end of the page)

http://ourworld.compuserve.com/homepages/Bill_Bowden/page2.htm#delay10.gif

but they are all "automatic", so driven by a 555 or something else, while I need it to be manual.

May be I've found a kit that will do this, is an old kit of an electronic paper of 7/8 years ago, I'm just waiting the sellers to reply to my request about the availability of the kit.

Still I would like to do it DIY like the whole pedalboard I'm building!

Thx again Andrew for your intereset in this.

Ciao
Armando
"it's a matter of objectives. If you don't know where you want to go, any direction is about as good as any other." R.G. Keen

The Tone God

Re: 7-segments diplay with 14543
« Reply #5 on: November 14, 2008, 01:59:42 AM »
When you turn on the Pandora does it always start at the same setting or does it remember the setting it was at when you turn it off ?

Andrew

arma61

Re: 7-segments diplay with 14543
« Reply #6 on: November 14, 2008, 02:16:11 AM »
It starts in the state it was before power off (same program, same volume/tone/gain settings), so I know I need to set the counter, every time I turn on the pedalboard, to the number present on the Pandora so they can match, but as I said I can leave with it, I don't gig I just play at home alone so it's fine for me in this way.

Armando
"it's a matter of objectives. If you don't know where you want to go, any direction is about as good as any other." R.G. Keen

The Tone God

Re: 7-segments diplay with 14543
« Reply #7 on: November 14, 2008, 02:33:41 AM »
Or you could store the number some how but if you don't mind setting the number each time maybe by putting a button on the side to tap to the right number every time you turn on then it is still doable. The 4017 is not a bad option if can live without a number being display but if you want a number then you can use a counter with a BCD output then feed it to the 14535. You then clock the counter with the footswitches.

Andrew