Electronics Question (arduino)

You could always put a small micro controller on the remote control (like an AT-Tiny) and gather the necessary data from each input device and then send down via RS232 (Serial 3 wires) a series of data packets whose values can be interpreted by the master Arduino (Uno i'm guessing) and sets those values to the servo's motors' and LED's?  That means you're going to have to power your remote control with a 9v and a switching regulator and then have at least a 3 wire cable going to the arduino.  You might as well use RS232 over USB since the master USB port on the Arduino will function as a functional RS232 port for data acquisition.

Heck go a step further maybe part 2 of your project once you have it working, get yourself an Xbee and go truly wireless.  Once you've built the RS232 communications protocol for the data its just a matter of changing the media by which the data is transfered.  Wired to wireless.

http://www.digi.com/products/wireless-wired-embedded-solutions/zigbee-rf-modules/zigbee-mesh-module/xbee-zb-module

Good Luck!

Hi Tim.

Thanks very much for your help.

That seems like a much better way then taking 7 wires to the arduino uno.

The Xbee would be a great idea however my budget wouldn't be able to stretch to it.

I'll let you know how i get on when finished.

Ricky

Sure,

Feel free to ask more questions during the development.

Should be a fun little project

Hi Tim.

Just a quick question for you, what model At Tiny would you recommend? And what programmer or can i program it via the arduino uno.

I have also attached a picture of the circuitry so far.

Thanks

First, the ATTINY85  is a nice unit with a fair amount of memory and capabilities. Ben uses them a lot in his designs. There are a number of ways to program it but for your project probably using the Uno would work.

Here is a nice Instructable how to do exactly that.

http://m.instructables.com/id/How-to-program-attiny-using-arduino-uno/

Check that out and give it a try. Gonna need a few parts which are all listed in there.

Tim

Hi Tim.

That Instructable looks fairly good and i have most of the parts already so i'll go with that.

Could you give me an idea what type of outputs i will be sending from the attiny to the arduino.

Thanks

Hi,

If you only have 4 wires and one is a ground, leaving 3 signal wires - you would need one for each pot - leaving 1 for the three switches.

This could be done using 3 different voltage levels or a 3 bit voltage level scheme on the last wire, or 3 different modulation frequencies.

Doug

Did you buy the ATTINY yet?

Hopefully not, if you did no biggy you're only out a couple of bucks and you'll use it someday.

However if you look on eBay for "Arduino Mini" there's a small micro controller Arduino with much more I/O and is available for about 5-8 bucks U.S. it would be easier to integrate and has all the I/O you'd need in your controller without having to do some high level programming.

It's a cheap Chinese knockoff but it's fully compatable.

Then the basic idea is to program the mini in the loop to monitor the current values of each input and create either a String or if you're comfortable with it a Byte array where you would add each value from each input. Separate the string values with like a carriage return char so you can parse them later easier. Then after you've built the string send it down to the other Arduino in the car serially and parse through the string applying each value to their respective outputs. 

I'd put a delay of 5-10 ms after that before looping again to ensure the Uno is finished before the buffer is hit again with another packet.

Congrats you've just design and hopefully programmed a protocol.

Totally agree with the Arduino Mini, Good shout.

You can also use the Arduino Nano, with a built-in USB interface.

Thanks Paul, Tim and Douglas.

That sounds like a good idea. I haven't bought the AtTiny yet but i might still get them as they are very useful.

I'll give a shot at programming the protocol and see how it turns out.

Also do you think i should use a Arduino Nano in the remote and in the car to reduce space.

All your help is very much appreciated,

Just another quick question any idea if the 2 servos and motor will work together if all running at same time, as the way i have it now only one servo works at a time and the motor loses considerable speed when a servo is active.

This might just be a programming error which i will check when i start programming the new program but i would like to get your opinion also.

Kind Regards

Ricky