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I am looking to buy the TP-132-042 (4WD All Terrain Robot Platform – IG42 SB) robot. I plan to use an Adduino to supply the PWM signal to make the motors turn at the speed range I want. Since I will load it up with a heavy load, I am going to use the Sabertooth Dual 25A Motor Driver. My question is can I still control the robot using the basic remote controller (Spektrum DXe Transmitter with AR610 Receiver). I ask because the driver name does not hav “RC” in it.
The sabertooth has multiple modes of control, RC being one of them. You can send a Arduino RC PWM pulse out, but its easier to use the Arduino with serial mode to control the sabertooth (there is a Arduino library for that). Not sure why you are using a RC receiver and a Arduino, but either will work. or you can send the rc signal from the receiver through the Arduino, then have the Arduino control the sabertooth.
I am building a robot for work and my boss wants to play with the remote control. :)
As for controlling the robot the way I need to, I want to move it along at a speed of between 0.1 – 0.3 meters/second. I thought that I would add an on-board Arduino UNO and use a pot to dial the speed I want with a LCD display to show the speed. I will calibrate the PWM signal to create the speed I need using the analogWrite() function. The PWM signal will feed into the sabertooth input. Can you verify if this will work?
I then thought of another idea. I may use a pair of Bluetooth enabled Arduino’s to create my own remote control. I would build the remote using an Arduino, LCD display, potentiometer and Bluetooth circuit. I dial the speed I want, press a button and it sends a command to the Arduino on the robot. That Arduino receives the command, interprets it and moves the robot. I will add a few beams along the path to tell the robot to stop or slow down when it interrupts them.
Your first idea should work as long as the Sabertooth is in the right mode.
Your second idea will work as well and we sell the individual parts and a wireless control package (link below).
xBee Control PackageDepending on your application, I would recommend a joystick input to an Arduino that constantly sends speed data through the xBee to your robot opposed to setting the speed then pressing a button. Either would work.
In my solution, I am worried about having the Arduino output go to two inputs on the Sabertooth. Your Xbee solution looks good, but it is very expensive, so I need to know if it will do what I need. Please comment. Here is my application. I want the robot to carry a load up to 50 lbs and move in a straight line at speeds from 0.1 – 0.3 m/s. That’s it.
So far, I have selected the following assembly. This is the dump from your order page.
Welded Aluminum Robot Chassis – IG42 SB
Download Wheeled ATR Assembly Manual
Electric Power Hookup Kit
ATR and Vectoring Robot Hardware Kit
Electric Motor Hookup Kit
15 Amp Connector Set
Female Spade Terminal with Heat Shrink (Pack of 4)
ATR Wheel Shaft Set Pair 8mm Bore – 6 inch pneumatic
IG42 24VDC 078 RPM Gear Motor
Interstate 12 Volt 7.2 Ah Sealed Lead Acid Battery (SLA) – 0.250 Faston
Battery Bracket \ Customized Battery Bracket(s)
Charging System \ Battery Charging system
Sabertooth Dual 25A Motor Driver
RC Controller \ No RC Controller
Assembly \ UnassembledIf I add the XBee package, will it all interface perfectly and allow me to build exactly what I need? Notice that I changed the motors to 78 RPM because they should still give me more than enough speed for my application while increasing the load capacity to hopefully 50 lb.
The advantage of xBee control package is that it supports a wide variety of applications. The joystick input to the Arduino allows for tank mode and/or vectoring mode depending on the wheels. So yes, this package will fit well with your layout. As shown on our page, the xBee control package includes source code and configuration for communication between the two Arduinos. We also provide a ReadMe with additional instructions.
You won’t need to worry about the communication between the Arduino and Sabertooth. The Arduino will be able to transmit data to the S1 and S2 ports.
OK thanks. Ideally if you could provide me with a quote for the parts I need with the options listed, I can get it ordered. I have to have a purchaser in another city do the ordering for me. If that is not easy to do, then I’ll have to provide this person with detialed instructions on what exactly to buy, down to each option.
Okay, first create an account on our website if you haven’t already. Place all of these items in your shopping cart, select the “request quotation” option, and checkout. It is important to make an account and enter the shipping address so you can be quoted for the shipping cost as well. This doesn’t require any financial information and you can change your order at any time before purchase.
The Arduino/Xbee page mentions that you also provide the custom source code. By this do you mean the program source code running on the two Arduinos? I can envision having to add external switches or IR/laser beams to act as limit switches so that the robot knows when I want it to stop. Will I have the ability to change the source code to add limit switches? If so, how many analog and digital I/O’s are still available?
The programming that’s included with the original price enables communication between the two Arduino’s and configures the output to match a control board of your choice. Any extra code will be an extra expense. More information on the capabilities of our custom work can be found here: Engineering Services.
You will have the ability to change the source code if you choose. We send you a disk including a copy of the source code for you to change and a ReadMe for additional instructions.
For your application, you shouldn’t worry about running out of I/O’s. Here’s more info on Arduino control boards: Arduino Info
I checked your GIT site and I believe I found the code under XBee-ATR. I examined the code for the remote and I believe that I can throttle the max speed by changing the following lines of code.
// The switch is towards the joystick (full speed)
tempFB = map(FB, 0, 1024, -126, 126);
tempLR = map(LR, 0, 1024, -126, 126);I believe that all I have to do is change the 126’s to lower numbers to limit my upper speed. That and perhaps not add 127 to them. I will have to experiment a bit. I don’t need much more than 60 ft/min.
I shouldn’t have any issues editing the Arduino code. I’ve written several Arduino programs to date.
You could also modify your speed factor on the robot side. For example, if you want half speed:
byteFB = 0.5*byteFB;
byteLR = 0.5*byteLR;ST.turn(byteLR);
ST.drive(byteFB);You could also go as far as adding a toggle button on the remote side that would switch speeds. But yes, experiment and see what you like. There are many options you could take in your design!
One more question. Can I turn TP-132-042 from a 4WD to 2WD system? I want one set of wheels to be on bearing mounts on a regular axle with no motors. For the powered axle, I will use the 78 RPM motors with encoders.
No. Its skid steer, if you don’t drive all the wheels, it will not turn regardless of how strong the driven motors are. The non driven wheels need to be casters if you want to do 2WD. We have 2WD platforms if you don’t want to do 4WD.
http://www.superdroidrobots.com/shop/item.aspx/2wd-tube-mount-robot-platform-ig32-sb/2114/
http://www.superdroidrobots.com/shop/item.aspx/2wd-mobile-robot-platform-ig42/2083/
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