Wireless foot pedal for my Tig welder

[gregs78cam]

Miller sells a wireless foot pedal for around $600, which seems a little expensive for what it does. The average foot pedal has only two components, a switch (for on/off), and a potentiometer(for current control). I was thinking it wouldn't be too hard to DIY something like this using maybe a couple of Arduino BTs, or some type of 2.4Ghz RF link. I just don't know where to start. I can go to the Arduino site and after about 10 minutes I am lost. Does anyone have any suggestions on hardware? I can learn the software side, and what better way than to immerse myself in a 'relatively' simple project. I was also thinking something like this might work as well:

http://www.digikey.com/product-detail/en/EZ430-RF2500T/296-23125-ND/1805795?cur=USD


Anyways you kind of get the idea. What do you all think?

[Six_Shooter]

I looked into that same pedal a couple years ago, and the price scared me away too.

My one concern of a DIY approach is the RF interference created by the welder itself.

Using an Arduino might actually be overkill for something like this lol.

If you really want to learn about it, get an Arduino (or two), Uno, or the Due, depending on whether you want to use an Atmega or ARM chip set, and the wireless modules, and start by sending simple on off signals between them, then add in the functionality of a variable input. You will need to use an analog read input and a PWM output in the end to do what you want to do, probably some other buffer circuit in there, to isolate the Arduino (or uC) from the welder.

If you really haven't working with C before, start with a single Arduino and get it to read the analog input either to the screen, or to an LED output of the same board. This will at least get you some of teh code you will need in the end.

Another development hardware to look at is the Teensy. I have both an Uno and a Teensy++ 2.0. I like each for different reasons, both use the same IDE, which is nice. I plan to be working on a few uC based projects this summer, I might have to add this one to list to help out.

Teensy: http://www.pjrc.com/teensy/

[gregs78cam]

I looked into that same pedal a couple years ago, and the price scared me away too.

My one concern of a DIY approach is the RF interference created by the welder itself.


I am pretty sure that the Miller uses a 2.4Ghz connection similar to the new RC stuff like Spektrum DSM or Futaba Fasst.



... I plan to be working on a few uC based projects this summer, I might have to add this one to list to help out.

That would be cool to get some help on this. I just looked at the datasheet for that TI eZ430 and it looks like it would work really well. What do you think? $40 for both ends and the battery pack/board.

[Six_Shooter]

I haven't looked at that one, but the xBEE modules seem to be favored in Arduino projects. This is partly due to the ease of connection set-up with the xBEE modules. There are shields available for the Arduino and wireless interfaces.

[Six_Shooter]

Sheild:
http://arduino.cc/en/Main/ArduinoWirelessShield

xBEE module information:
https://www.sparkfun.com/pages/xbee_guide

[EagleMark]

I am pretty sure that the Miller uses a 2.4Ghz connection similar to the new RC stuff like Spektrum DSM or Futaba Fasst.I have an old three channel 2.4ghz controller here if you want it? May also have the servos...

[gregs78cam]

I have an old three channel 2.4ghz controller here if you want it? May also have the servos...

Do you happen to know the brand, some are not compatible others, as far as Tx and Rx. Unless you have both the Tx and Rx, then I could maybe make something work.

[EagleMark]

Spektrum DX3

[Six_Shooter]

I was looking for one of those a while ago. lol

[gregs78cam]

Oh yea, I have one of those with my Revo. HobbyCity has a few cheap Chi-Com Rx for the Spektrum stuff. I might pick that up from you next time I am over that way, and drop of your throttle body that I don't need.

[EagleMark]

What throttle body? I want to make sure I want it back first! :laugh: Trying to clean up around here...

This one still worked fine on the rock crawlers, but antenna got broke and the kid has not played with toy rock crawlers since he got a real one...

[Six_Shooter]

Anymore RC parts that you'd like to clean up? :D lol

[gregs78cam]

I would like to sell my Revo. I guess I should CL it one of these days.

[EagleMark]

Anymore RC parts that you'd like to clean up? :D lolNo all gone, kid lost iuntrest and sold them all for real rock crawler money, only thing left was the controller...

[gregs78cam]

Six, I took a look at the Teensy, and it seems to be adequate for what I am looking at. Make sure I am correct here, I would need a Teensy to take the pedal's on/off (digital), and variable (analog) inputs, convert them to a digital signal, send it connected XBee, which would transmit the signal to the receiving XBee, then it would get passed on to another Teensy to get decoded, and tied into the foot pedal connector on the welder. Right?

So I would need two Teensys, two XBees, and two adapters for them? Seems reasonable.

[Six_Shooter]

Six, I took a look at the Teensy, and it seems to be adequate for what I am looking at. Make sure I am correct here, I would need a Teensy to take the pedal's on/off (digital), and variable (analog) inputs, convert them to a digital signal, send it connected XBee, which would transmit the signal to the receiving XBee, then it would get passed on to another Teensy to get decoded, and tied into the foot pedal connector on the welder. Right?

So I would need two Teensys, two XBees, and two adapters for them? Seems reasonable.

Yep, that's how I would attack this.

Actually I would likely try to reduce the need for the Teensy down to just a uC, with the supporting power supply hardware. You can look up terms like "making your Arduino Project smaller" or similar to get ideas on how to do that. For initial development using a pair of dev boards and XBee modules will get proof of concept and prototype working.

[gregs78cam]

Well I was looking around and found the programmable XBee and thought about using that as it looks like it would do exactly that: combine the uC with the RF module. But cost would be more than I want to spend right now. I have a couple of high quality switching power supplies that a friend gave me from his work, they are about the size of 3 stacked quarters and work very well at regulating 5V. I figured I can use one in the foot pedal with a 9V battery, and possibly one in the Rx if the welder can't supply the needed voltage/current.

[gregs78cam]

So I pulled the trigger on the Teensy 3.0 for a different project that I will use as a learning tool to get into these affordable micro-controllers. Then I realized that the 3.0 is 3.3V and I need 5V capable for this other project. So I ordered a 2.0 also for the other project and will use the 3.0 for this one when I have time. I will post up a new thread on that subject when I get some time to work with the software, because I have few questions.

[bentrod]

never used teeny but have heard a lot of hype about it recently. Same goes with adruino; which seems to be popular with the crowd of people who want to do quick one off projects without learning too much about microcontrollers. For your project, it might be the easiest route so you can get on with your overall goal (welding wirelessly).

I develop electronic hardware for a living if you need some ideas or something cleared up I might be able to help.

[gregs78cam]

Cool, thanks, I will keep you in mind in case I need a brain to pick.