This Instructable is one part of a six-part series that will go through building the Zybot. This Instructable will guide you through everything you need to assemble the hardware of the Zybot. The Zybot is a robot that is controlled by an Xbox controller through WiFi. It also has a camera that you can access via the WiFi. The ZYBO is an embedded software and digital circuit development board that we are using to run Linux.
At this point you should have completed the power considerations instructable.
We are going to be setting up the hardware for the robot. Including the body, motor, camera arm and other miscellaneous parts we need for the robot to run. To make the Zybot you will need a lot of materials. I don't want to make a huge list here so I will list the parts in the next 3 steps, grouped based on where you might find these parts.
Step 1: Gathering the Parts - Digilent Parts
Since this project was an intern project at Digilent, most of the parts you need for this project come from Digilent. These parts include:
Note: For those of you with a 3D printer, rather than screwing these three parts together you can print the body all in one piece using this design.
- 2 Motors
- 1 Wheel Kit (D-hub)
- 1 Wheel Kit (Spined - hub)
- 1 6 Pin Header
- 2 Pmod HB5
- 1 PmodCON3
- 3 Pmod Clips
- 1 ZYBO
Note: You will end up using a lot of screws in the assembly of the Zybot. Conveniently all of the hardware kits come with screws, so you will have more than enough screws for this assembly if you purchase all of these Digilent Parts.
If you notice, I have 4 6 pin connector listed here. Each Pmod comes with one right now. The way the 6 pin connector cables are sold will change soon so check before you order them.
Step 2: Gathering the Parts - Miscellaneous Parts
Along with the parts that could be purchased at Digilent, there are several other parts you will need to assemble your Zybot:
- Red Wire
- Black or White Wire
- 1 webcam
- 1 Wireless Adapter
Note: The voltage regulator I used was a discontinued Digilent part we had in the office. I linked to a similar one that should work. Unfortunately, it is different sized and will have to be connected differently than the one I use in this tutorial.
Make sure you read the power considerations instructable before choosing your voltage regulator!
- Electrical Tape
- 1 Drag Button
Note: The Drag Button I used is included in the Digilent Robot Kits but is not sold separately at Digilent. So, If you have one of those that would be easiest, otherwise you can use one of the ball and casters such as the one I put a link to. Unfortuately non that I could find were tall enough so you will have to add height to it reaches the full 2 inches it needs to be.
- Zip Ties
- 1 USB Hub
- 2 3/4 inch screws
- MTE to battery connecter
Note: You may have to do some soldering to make this cable. I needed an MTE because that is what the input of my voltage regulator is and then the special connector my battery has.
Step 3: Gathering the Parts - Tools
Step 4: Assemble the Platform (Skip This Step If You 3D Printed the Platform)
Using the wider screws, screw the two Base plates together on the 6th hole in on the bottom base plate. Then using two more of the wider screws attach the Rounded Plate Expansion Kit to the first hole on the base plate.
Step 5: Attach the Motor Mount
The next thing we need to do is attach the motor mount to the platform. We have to put the motor mount fairly far forward because we are going to put a lot of heavy stuff on the front, and we don't want to have balancing issues.
The ideal place to attach the motor is to put the front hole of the motor mount in alignment with 3rd hole in on the rounded bracket. For those of you who 3D printed the platform you can do this. Unfortunately if the platform is built out of multiple pieces there is a screw right in the way.
Don't worry though, we'll just put the motor mount a little farther forward. Align the motor mount so the edge is touching the edge of the Base plate. Screw these together with the wider screws. Place the screw in the farthest back hole of the motor mount and the hole on the rounded bracket directly in front of where the base plate is attached.
Step 6: Mount the Motors
Screw the motors on to the motor mount using the tiny screws that came with the motors. Make sure the wires coming out of the motor face the base plate.
Warning! The screws that come with motors are sneaky little guys, if you drop them, you will never find them.
Step 7: Attach the Wheels and Drag Button
Using the same sized screws as before, attach the drag button to the farthest back set of holes as possible.
Attach the wheels with the D-hub to the motors, and put the sticky tires on.
Step 8: Attach the Pmod Clips for the H-Bridges
Using the included screws and nuts, attach one of the Pmod clips to the 5th hole down and second hole in on the Base Plate, and the second in the same place on the opposite side.
Step 9: Attach the H-Bridges
Clip the H-bridges (PmodHB5) into the Pmod clips and attach the motors to them.
Step 10: Attach the Zybo
Flip the platform over so the button and wheels are on the bottom.
Attach the ZYBO using four extra screws from the hardware kits and the standoffs that come on the ZYBO. Attach it on the fourth row of the base plate.
Step 11: Attach the PmodCON3
Plug the Pmod CON3 into the bottom row of port JD. Remove the blue jumper.
Step 12: Attach the USB Hub
The next thing we need to do is attach the USB hub. We need to place it right in front of the screws attaching the drag button. The Zybot gets jostled around quite a bit, so you'll need to attach it very securely. I use 3 zip-ties. Plug the USB hub into the USB port on the ZYBO.
Step 13: Tape the Pmod Cables Together
Using the electrical tape, tape the Pmod cables together. Stick a six pin header in each cable and connect them together so they are electrically connected. Pay attention to the flowers on the cable. The flower indicates which pin connects to which on either side of the Pmod cable. To make sure there is no confusion make sure the flowers are together.
In the first image although the flower on the second cable is on the bottom side it is lined up with the flower on the first cable on the top side.
Step 14: Connect the H-bridges to the Zybo
Use the cables you just created to connect the ZYBO to the H-bridges.
Plug each cable into the H-bridges, insuring that the flower is on pin one of each H-bridge.
Plug the right H-bridge into the top of port JE, and the bottom H-bridge into the bottom of port JE. Again make sure the flower of each cable is attached to pin 1. Use the 6 pin, pin headers to connect the cables to the ZYBO port.
Step 15: Tighten the Loose Cables With Zipties
At this point you probably notices that the Pmod cables are dangerously loose. We can fix that with a few zip-ties. Zip-tie the cables down keeping the bulk to the cable as far back on the Zybot as possible.
Step 16: Connect the Two Servo Brackets
Next we are going to connect the two servo brackets together. Connect them so that the short side of one servo bracket is attached to the back on the long side of the second. Use two of the screws from the servo bracket kit.
Step 17: Connect the Servos to the Servo Bracket.
Attach the servos to the brackets using more of the screws from the servo bracket kit. The top servo should have the circular connector screwed on, and the bottom servo should have no servo connector screwed on.
Step 18: Connect the Single Motor Mount.
Connect the single motor mount to the circular servo connector, so that there is an arm and a place for the camera to sit on. If you used the 3d printed part you can glue the arm on, otherwise you will have to screw together the two single motor mounts and screw them on to the servo.
Step 19: Attach the Camera
Next dettach the camera hinge and glue the camera on to the arm you just created.
Step 20: Create a Base for the Servos
Using the 3/4 inch screws. Attach one of the spined-hub wheels to the far right front of the Zybot. Then connect the servo to the wheel. You may find the need to hot glue the servo into the wheel if you end up driving the Zybot too wildly.
Plug the servos into the PmodCON3, paying attention to power and ground, and connect the camera to the USB hub.
Step 21: Consolidate the Cords
The servo cables need all of the room that they have for the servos to have full motion so we can't organize their cables. However, we can zip-tie down the lengthy camera cable. Leave a bit of slack for the camera to move and then zip-tie the cable in place. `
Step 22: Connect the Battery
To connect the battery we are going to create two Velcro loops for the battery to sit in.
Cut two pieces of Velcro about 4 inches long.
Separate the Velcro and then attach it back together overlapping only as wide as the battery.
Trim the Velcro so that when you fold over each side it reaches only to the other side of the battery.
Close the Velcro so it forms loops and glue those loops in the middle of the Zybot underside.
You know have resealable loops to hold the battery in place.
Step 23: Connect the Voltage Regulator
The voltage regulator that I am using is conveniently the size of a Pmod so I can use a Pmod clip to attach mine. Depending on the voltage regulator you use, you may have to get creative with how you attach it. Put the voltage regulator somewhere close to the ZYBO power pins and the PmodCON3.
Step 24: Power the Motors
At this point do not have the battery plugged into anything. We do not want to be messing with wires and various boards connected to power until we have all of our connections made and secure. Also be sure you have read the instructable on Power considerations for the Zybot.
The motors require 12V. So, we want to connect the 12V side of the Voltage regulator to the motors. For the regulator I am using there is a handy set of screw terminals that I can use to connect to the 12V side.
So, first I need to two sets of red and black wire long enough to go from the H-bridges to the Voltage regulator. Mine ended up being about 11 inches long. Then I will strip about 1/4 inch of the insulation on each side.
Then I will connect them to the screw terminals.
Note: The way you connect the Voltage Regulator and motors may be different depending on the connection style of your voltage regulator. In any case you are connecting the 12V side to each H-bridge. Be vary careful that you pay attention to which side is power and which is ground!
Step 25: Power the Servo
This step may seem a little weird to those of you who have some electronics experience.
Take one of the two pin MTE power cables, and plug the power side onto the VS pin of the PmodCON3 and plug the other end into the 5V side of the voltage regulator. The servos can only take 5V.
Again, make sure that the power and ground are connected to the respective pins.
It may seem weird that we are only connecting the power side of the PmodCON3. The PmodCON3 will already have a common ground with the ZYBO since it is plugged into the ZYBO so it doesn't need a ground pin. However, this means that you must have all of the power connections done before you plug in the battery, otherwise the servos will float.
Step 26: Power the Zybo
The last thing you need to plug in before you plug in the battery is the ZYBO board. The ZYBO board can only handle 5V!
Take the second MTE cable and plug that into the 5V side of the voltage regulator. The other side of this will be connected to the ZYBO board. Remove the blue jumper from JP7, which is by the power switch. Plug the MTE cable into the GND and VV5V0 pins paying close attention again to connecting power to power and ground to ground.
Step 27: Plug in Your Power Source
This is again going to be different depending on the voltage regulator. The one I'm using has a set of input pins. So I take my special batter to MTE cable and plug the power side into the Vin and the ground side into the GND.
I would highly suggest testing the voltage regulator current and voltage at every pin to make sure that you aren't going to destroy any part of the Zybot, particularly the ZYBO. I did not use the voltage regulator that you will be using so I don't know for sure the current and voltage. On top of that it is extremely easy to get pins mixed up and power something incorrectly.
Step 28: Yay! the Hardware Is Done!
Congratulations, you have now completed the hardware for your Zybot!
Continue on to the controller instructable so you can drive your Zybot around.