Anyone know how to rework circuitry?

**HiJackZX1** · 09-02-2009, 02:53 PM

Originally Posted by cMags

Could be accomplished using a 555 timer to output a 1-shot (monostable) pulse. You can configure how long to hold the pulse via external circuitry.

http://www.kpsec.freeuk.com/555timer.htm#monostable

I bought a 555 times, but I do not understand how to use it

**soundman98** · 09-02-2009, 03:52 PM

here is the non-techie iteration of the mono stable circuit--i copied the design straight out of cmags link, before building it though, you might want some of the more circuit oriented people look over it to make sure it is correct:

for referance, here is the original schematic:

edit: i forgot the capacitor from pins 6&7 to ground....

**Curiosity** · 09-02-2009, 06:38 PM

You might be able to simplify the design based on how the DQP operates. Such as knowing how the button works. One side of the button is either ground or power (5V or 12V possibly) and the other floats (changes when pressed). That could help with interfacing your circuit to it. There could also be logic chips, relays/fets or even a PIC, and could be initialization logic that you could modify depending on what's in there. The main thing would be what's connected to that button?

**HiJackZX1** · 09-02-2009, 10:12 PM

Originally Posted by Curiosity

You might be able to simplify the design based on how the DQP operates. Such as knowing how the button works. One side of the button is either ground or power (5V or 12V possibly) and the other floats (changes when pressed). That could help with interfacing your circuit to it. There could also be logic chips, relays/fets or even a PIC, and could be initialization logic that you could modify depending on what's in there. The main thing would be what's connected to that button?

I honestly have no idea.... here are pix of the DQP board. All the buttons have 2 features. For the 3 way mode, a quick press of the button switches to 3 way, then 2 way, then single screen. The first press of that button goes to 3 way. Now if you hold it in for to long, it will go into this weird zoom mode.

**Curiosity** · 09-03-2009, 05:12 AM

You could just leave it powered if it didn't take much power. It looks like it might be a bit much though.

Well, let's see...
EtronTech = frame buffer for Techwell
Techwell = 4 Channel Video QUAD/MUX Controller
WinBond = Microcontroller
74HCT573 = Octal D-type transparent latch; 3-state (interface between the two)

The winbond probably routes to the 2x10 pin header. Does that connect to a board with buttons and LEDs? Are there any chips on that? It could connect directly to the buttons, but could also have some logic or I2C.

**HiJackZX1** · 09-03-2009, 08:49 AM

Originally Posted by Curiosity

You could just leave it powered if it didn't take much power. It looks like it might be a bit much though.

Well, let's see...
EtronTech = frame buffer for Techwell
Techwell = 4 Channel Video QUAD/MUX Controller
WinBond = Microcontroller
74HCT573 = Octal D-type transparent latch; 3-state (interface between the two)

The winbond probably routes to the 2x10 pin header. Does that connect to a board with buttons and LEDs? Are there any chips on that? It could connect directly to the buttons, but could also have some logic or I2C.

It runs on 12V, at 1amp...... Um, looks like you know your stuff, lol... All I see is a bunch of curcuits.

Yes there is a seperate button board that connects via a ribbon cable. Two of the headers are what trigger the view modes. So I have wires coming from those (not pictured).

**Curiosity** · 09-03-2009, 11:09 AM

Oh you already have it setup for external control! Well, a timer would be best since it's not just logic chips. Bsxtees actually had a good idea. You need a delay and then a pulse, probably around 1 second delay, then 200-500ms pulse. With the 555 (2) you need a 2 stage, both monostable. One with a 1 second pulse that triggers the second. The counter would take less components though. An optocoupler may be easier than a FET though since we're not sure if that's a pull-up or pull-down switch.

**HiJackZX1** · 09-03-2009, 11:38 AM

Originally Posted by Curiosity

Oh you already have it setup for external control! Well, a timer would be best since it's not just logic chips. Bsxtees actually had a good idea. You need a delay and then a pulse, probably around 1 second delay, then 200-500ms pulse. With the 555 (2) you need a 2 stage, both monostable. One with a 1 second pulse that triggers the second. The counter would take less components though. An optocoupler may be easier than a FET though since we're not sure if that's a pull-up or pull-down switch.

LOL, see your starting to sound Alien to me, thats why I wanted someone to make it for me and I'd pay them for it.

You mean the button its self? All i know is you touch the 2 wires together and it will go to 3 way mode, lol.

Its funny though, I am sure this is so simple, but my mind is weird. Hard $h!+ that is so complicated sometimes, is so simple to me. But simple things will shoot right over my head.

**Curiosity** · 09-03-2009, 11:47 AM

Oh, I sell something that does that. It's in my sig.

The 555 timer is confusing even after looking at tons of examples until you play with one. Then it's all pretty simple.

**HiJackZX1** · 09-03-2009, 01:02 PM

Originally Posted by Curiosity

Oh, I sell something that does that. It's in my sig.

The 555 timer is confusing even after looking at tons of examples until you play with one. Then it's all pretty simple.

OMFG, you sell alot of stuff... which do I need?

Basically when power is applied, I need it to push the button, then the timer thingy turns off and stays off until power is reapplied again!