Using arduino to control machine - simple question

Projects General Guidance
1

I have an engraving machine i'd like to build an alternative controller for. The keypad controller part of the engraver is pretty simple. It has 9 separate buttons which are controller by closing a circuit between 6 wires. For example:

Go (pins 1 & 4)
Pause (pins 1 & 5)
Shift (pins 3 & 6)
Check (pins 1 & 6)
Z (pins 2 & 6)
Up (pins 3 & 4)
Down (pins 3 & 5)
Left (pins 2 & 4)
Right (pins 2 & 5)

I'm pretty new to the arduino - i'm trying to figure out how i could close the connection between pins with the arduino to perform the function?

2

Well without knowing anything about the electrical side of the machine, the simplest method would be to use 9 relays controlled by the arduino and the relay contacts would make those connections.

Lefty

3

It sound like a matrix of buttons. What would mean a transistor like 2N2222 between the pins of the engraving machine and the basis connected to an Arduino pin would do it. But to what pin to connect the collector and the emitter I don't know. Perhaps if you would post some more info (images etc.)

JanD

4

You could use four 2-throw relays. Basically, you need to switch among 1, 2 and 3, and among 4, 5 and 6.

The first relay switches between 1 and 2. Second relay switches between the first relay and 3. Third relay switches between 4 and 5. Fourth relay switches between third and 6. Output of fourth and second are connected.

Each relay is connected to a pin on the arduino.

5

Using a relay would take away the need to know how to connect emitter and collector. So that would also work good.

JanD

6

JanD:
Using a relay would take away the need to know how to connect emitter and collector. So that would also work good.

JanD

Or needing to know if the machine might be using AC instead of DC paths through those connections. Lots of unknowns without detailed circuit knowlege of the machine, but relays can make us all seem smart. :smiley:

Lefty

7

Here's some photos of the control panel:

[Album] imgur.com
8

Pins 1-6 are outlined in the above message. Pins 7-8 and 3.3vdc and 9 is a ground. There are two very small LED's on the panel.

9

As relays are like switches, only that they are closed be electric and not by mechanic, so that would be the best. Just connect the relays instead of the switches and connect the other two pins of the relay to ground and an Arduino pin.

JanD

10

Thanks everyone for your suggestions. I ended up going a bit of a different route by using a custom made PCB and an NES controller. End result is great and even simpler without the need for a microcontroller. Below is the finished product: