For this instructable I will show you how to make and program a robotic arm (like this one) using an Arduino or an Arduino clone. I will show how to make this using a Maplin robotic arm with USB PC interface but the same applies in this for all dc motor controlled electronics
Step 1: Equipment
1. A robotic arm using dc motors (this can be home made e.g: using a 3D printer or the one I am using has been bought from here).
2. An Arduino UNO or an Arduino UNO clone (these can be bought from almost any electronic store, be it online or in a shop).
3. An Arduino UNO Motor Control Shield (this can be bought here or from other stores, make sure you get one with the same layout as this).
4. Jumper wires (solderless) of all types (Male-Male, Male-Female, Female-Female).
5. A 5V (5V0) USB mains plug (these can be bought literally anywhere if you don't already have one [this would be very unlikely])
6. An Arduino USB programming cable.
7. The Arduino IDE (this can be downloaded from here, the current version is 1.0.6 but should work on all future and previous versions of the IDE, (if you are using the Raspberry Pi get the IDE through the LXTerminal and type "sudo apt-get install arduino" then press "y" and it will install)).
8. A PHILIPS flat head screw driver
Step 2: Arm Deconstruction
1. Get you arm out and unscrew the yellow plate and black battery compartment from the back of it.
2. Unplug the motor leads.
3. Remove the PCB and all leads and cables attached to it.
4. Remove the batteries and the other components in the back of it
5. On the removed cable mark on positive and negative sides (see image)
Step 3: Setting up the Motor Control Shield
1. Attach the shield onto your Arduino UNO.
2. Plug the Arduino in and check the green light on the shield turns on (this tells you that it is working), then unplug the UNO.
3. Loosen the screws on M1, M2, M3 and M4. (the middle screws are not needed). (a PHILIPS flat head screwdriver will loosen both the cross and flat screws).
4. Get 8 of your Male to Male Jumper Leads and insert them into the recently unscrewed openings and then tighten them up again.
5. Then get another two leads and place them in the external power port after loosening them. (Try to put a black or blue lead on negative and a red on positive for reference).
Step 4: Uploading The Sketch
Now we will upload the sketch to control each of the individual motors, but first we need to add the libarys to the IDE as well.
Step 5: The Boring (but Quick) Bit
Now it is almost time to put the arm together but first you need to work out which motors you will attach to what terminals on the shield. As there are only four terminals on the shield and five on the arm unless your tobotic arm uses less lable the motors "M1" to "M4" working your way down the arm (I missed out the wrist motor).
Step 6: Building Again
Now wire the M1 labled cable to the M1 terminals on the shield and so on. Then attach the old USB cable to the power terminals and connect the USB interface cable to reprogram the arm when you want to. Now feel free to put rhe pieces in the back of the arm whrre the batteries were or place in an enclosure to protect the pieces then plug in the plug to the power USB and test!