I am currently using NXT platform for my students who do the robotics soccer project. Due to the size of the brick and motors, it is extremely difficult to make it as small as 22cm for all sides. In addition, due to the limitation of 4 sensors ports, we have to tag along a multiplexer… increasing the size even more!!
I am looking to switch. I run into arduino… my difficulty is to locate all necessary components for our soccer project.
**Criteria includes: ** ]no soldering is needed/:m] ]Easy to make a bot which is within 22cm in all dimension/:m] ]Processor capability of floating point calculation /:m] ]Software interface (prefer to be in C) which allows event driven structure and multi-tasking./:m] ]Minimum 3 motors /:m] ]Lcd/:m] ]Led (I guess I get this any radio shack… but need to know how to attach it onto the controller though)/:m] ]Minimum types of sensors including IR sensor, ultrasonic sensor, li/:m]ght/reflective, compass.
I seem to have difficult to determine that exactly what I should purchase from your list on the website.
Questions:
if using Pololu 3pi Robot USB Programmer and Cable Combo, I still have to look for compass and accelerometer sensors compatiable with it. Suggestion?
if i order each part from robotshop, wonder if someone can help me to list the parts I’ll need, such as :
]Pololu 3pi Black Expansion Kit (with Cutouts) /:m] ]Arduino Duemilanove (2009) , or Pololu controller /:m] ]Orangutan USB programmer/:m] ]USB7 6 Digit LED Display Kit/:m] ]Where is the breadboard for it? /:m] ]Solarbotics Gearmotor GM_2/:m] ]Solarbotics Gearmotor GM_3 /:m] ]D/:m]irection as how to mount this motors onto the cutout board
2nd level? do you mean 2nd physical level? So, can I buy one of those cut out board, Pololu 3pi Black Expansion Kit (with Cutouts)
Product code : RB-Pol-79 . and mount on top? that’s ok, I think.
I do want servo motors as I need the tachometer feature.
but, can the 1st level accomodate the following, including:
]compass, /:m] ]IR to detect infrared objects (with a 135 degrees viewing angle)/:m] ]some kind distance sensor/:m] ]3rd servo motor./:m]
I have played with the C programming software. They do not seem to support multi-tasking, or event-driven control structure. Am I incorrect?
And they all are so much more costly!
I am looking for kit that I can potentially use for all my advanced students. I have 8 kids doing robotic soccer now… and will have more in the future. Therefore, once I decide exactly what to use, most likely, I’ll continuously invest into more. That’s also why I need to figure out a cost-effective way to do this.
I am leaning more to Pololu 3pi robot. I should purchase one to test it out. For the preliminary test, i need to :
]track line /:m] ]avoid obstacle/:m] ]identify multiple colors (wonder if the reflectance sensor can do it!)/:m] ]tell x-y axis with an accelerometer /:m]
After i played with these, I should be able to proceed with more complex test with compass too
I just noticed that the 3pi kit comes assembled. I would rather to get the parts which I’ll do it myself. that also means a lot of soldering to do… Yes, I’ll have to learn it.
Parts list?--------------------------------
Pololu 5" Robot Chassis RRC04A Solid Blue, $8
Pololu Orangutan LV-168 Robot Controller (+ Pololu Orangutan USB programmer, $28), $53 OR
Pololu Orangutan X2 Robot Controller VNH3 + LCD, $140 (don’t need the usb programmer, correct?)
Pololu QTR-8A Reflectance Sensor Array, $15
Pololu Ball Caster Variety Pack, $28
Pololu Micro Metal Gearmotor Bracket $6 (3 of them)
Pololu 100:1 Micro Metal Gearmotor, $48 (3 of them)
Encoder for Pololu Wheel 42x19mm , $45 (3 of them)
Pololu BCM Wheel $6 (2 of them)
Pololu MMA7260QT ±6g Triple-Axis Accelerometer , $20
Pololu Ball Caster with 1" Plastic Ball, $7
No, I’m not sure… we want to create a bot with the capability of :
detect IR object with a good vieiwing angle
detect distance on a mobile contraption like a 180 degrees moving head.
detect orientation instaneously with a compass (don’t want to use encoder to avoid accumulative errors)
detect incline with accelerometer
the whole bot must be within 22 cm.
a controller allows some sort of multi-tasking will be extremely helpful, as we do a lot of triangulation and constantly monitoring orientation and existance of IR object.
With these said, I have very hard time to find anything except the Mindstorms… as strange as it sounds… ! However the processor brick is huge too. I had to get a multiplexer to get all the I2C sensors that I need.
I can deal with pretty complex robotic programming in C, just with the hardware!!!
Recommendation???
I looked at the rover kit you suggested, the diagonal measures 0.2cm over 22. Unfortunately, the game that we are in does have very straight rule about the size. The bot must fit in 22cm cylinder!
Reviewed the Parallax Hitachi Compass module. But, it looks like it is compatible with parallax models? We do not use Basic.
About the accelerometers, I wonder if there will be some sort of tutorial from Arduino to provide clue in the programming interface.
Without Encoder, we’ll have to calculate ourselves based on the power output + timing… Two big attractions from the Pololu, the encoder wheels set, and multi-tasking capable controller. But, I could not find any compass compatible with it or anything which will help me to tell my orientation…
Welcome to the RobotShop Forum. Many robot platforms will require some soldering. You indicate the Pololu 3pi robot is of interest (definitely a speedy little robot that meets most of your criteria), though to add the second level, you will need to solder components. The RobotShop Rover has almost no soldering required and meets even more of your criteria, though it is not fast. Almost every option with Arduino will require soldering and custom robotics.
You may want to consider VEX robotics, and it should be easy to make a robot that fits within a 22cm cube. The microcontroller is programmable in C and includes enough motor and sensor ports to make complex designs. There are a variety of different starter kits available.
You can add sensors to the first level of the 3pi robot, though it would require soldering and additional custom mechanics. The Expansion Kit is a “second level” for the 3pi robot and also requires soldering. The Pololu 3pi robot uses two DC Gear motors - not servo motors. An additional servo motor can be incoporated, though this would not be a “plug and play” solution.
Unlike LEGO’s motors, most robot kits do not include encoders for feedback, and turns are based on speed and time. Very few controllers support multi-tasking. Parallax will be coming out with a new robot called the “stingray” which uses the Parallax Propeller chipset which can handle about 8 different commands simultaneously. The Stingray is set to be released soon. http://admin.robotshop.ca/content/images/learningcenter/stringray.JPG
There are no specific servo ports on the 3pi, so you would need to connect the input signal to a digital output of the microcontroller, as well as the ground to ground, and ensure the voltage is between 4.8 to 6V. You would need to wire this yourself on the second level. With regard to sensors, you need to determine if you are ready to solder. For example, a good, low-cost compass module is the Parallax Hitachi HM55B, but this is almost component level. Before selecting components, you may want to determine which platform is best and if you will consider components that require soldering.
This approach certainly is very different than going with a pre-made robot. If you want to use the Pololu round chassis, it’s important to note that works with the Tamiya Twin Motor Gearbox - the motors you selected are not compatible. Also, the wheels you chose are not compatible - you would need Tamiya wheels. Consider going with the round robot chassis kit instead. You won’t need any of the ball casters in this case. The other items you chose most likely will not fit directly onto the chassis, so you will need spacers. I’m also not sure why you chose 3 drive motors? If you take this approach, you will need some custom made hardware to support the reflection sensor array and a variety of other components. Are you sure this approach best suits your needs?
Except for the fact that you would need a solder a few components, the RobotShop Rover for Arduino seems ideally suited to your needs; you can easily add all the sensors, it includes the servo turret. The motors rotate at 66rpm and the drive wheel is 1.5", meaning it will travel ~25 feet per minute (~5" per second). If this is sufficient for your needs, the rover would be a suitable platform.
Actually, the Rover’s diagonal measurement is 20cm, so it would fit within the 22cm cylinder. The longest measurement is 15.5cm and the width is 15cm. Note the shape of the rover is not a perfect rectangle. The track length trom end to end is 12.6cm. The front of the robot includes a universal mounting point which can be easily adapted for soccer, sumo and other competitions.
There is no R/C version of the RobotShop Rover For Arduino, nor does the basic kit include an accelerometer. You would connect the additional sensors to the included mini breadboards. There is an infrared distance sensor included that is mounted to the front of the frame. All motors (2x drive and 2x servo) are included as well. Consider the Parallax Hitachi Compass module. You can mount an infrared and/or ultrasonic sensor(s) to the front servo to scan for both infrared objects and get their distance. We have a variety of accelerometers to choose from. If you find the three breadboards are not enough to mount everything, it’s very easy to build a second level. You can get a rudimentary measure of distance by including a magnetic sensor on the frame and a small magnet within the wheel. Unfortunately the track kit does not allow room for a standard optical encoder.
