I have a couple of 8.4V NiMH rechargeable battery packs laying around, previously used in R/C and airsoft stuff. Can I use those with the Rover (V1.5 if it matters)? Any precautions I should think of, other than polarity?
Thanks, I’ll use 4xAA meanwhile but I thought the voltage regulator would reduce the voltage up to 9V? Edit: Meaning it would adjust 6-9V down to a voltage the motors would handle.
Anyways, the top left led is not lit when all the others are. This seems to be a general problem and I know you offer free RMAs for this, but are there any problems with this apart from the LED not lighting up (which I really don’t care about)?
Hi EdZilla,
Your feedback is appreciated. The concept behind this robot is actually fairly simple: Design a bare-bones tracked vehicle based on the Arduino Duemilanove. The PCB itself incorporates an Arduino Duemilanove (with surface mount ATmega328 chip) that is shield compatible. The area in front of the board incorporates an L298 dual motor controller chip and two pairs of screw terminals, as well as extra space for a solderless breadboard or cargo. The “rear” (the area where you connect the USB cable and power) is also extended to include a voltage regulator. Therefore the PCB alone can be used as a normal Arduino Duemilanove.
If you are entirely new to programming, we suggest using the PCB alone (which is based on the Arduino Duemilanove) in order to familiarize yourself with basic programming in Arduino following the Arduino: Learning page. You can also take a look at the RobotShop Learning Center: Arduino 5 minute Tutorials.
Note that there are two analog sensors connected to the board which you can use when you reach step 3, as well as an LED connected to digital pin 13. After you have mastered the basics, you can follow the subroutines in the sample code to understand how to send commands to the motor controller.
If you have already programmed before, the user manual includes sample code starting at page 14. You need to first download the Arduino software:
The sample code is intended to be used with Hyperterminal (if you are running Windows 7, Linux or MAC you will need to download it separately).
Hi sgpo,
We’re happy to hear that the unit works tethered (so the hardware itself is fine). It is likely a communication protocol error for the wireless modules (we would be happy to provide first level technical support if you can provide more details). The temperature and light sensors included on the board are both analog and provide a value between 0 and 1023 (after A/D conversion) on pins A0 and A1 on the board. These sensors are intended to help a user get started immediately with sensors. You can refer to the analog sensor tutorial on the Arduino website. In order to avoid obstacles, you will need distance sensors (infrared or ultrasonic). The Lynxmotion sensor multi-purpose sensor housing or Robotics Connection Sharp IR turret can be directly connected to the front of the rover to help with mounting the sensor(s). Although not tested with the Rover, the Robotics Connection Sharp IR Sensor mount may also work well. A very good “seeking” sensor is the Pololu IR beacon (pair), which allows the robot to orient itself with respect to another object using six infrared sensors each set to different frequencies.
Hope this helps,
Hi Ed,
Bluetooth is a communication standard, so in theory any bluetooth enabled device can communicate with it. The DFRobotShop Rover Bluetooth Kit includes both the Bluetooth module to attached to the rover, as well as the USB Bluetooth dongle for a PC. The range is about 10m line of sight.
XBee is often used for longer range and requires two XBee modules; one on the robot itself and another to transmit/receive the data. To do this, the DFRobotShop Rover XBee kit includes an XBee shield, two XBee modules and a USB to XBee board (to connect to your computer). The range is about 120m line of sight and significantly greater with the Pro versions.
Both the DFRobotShop Rover XBee and Bluetooth kits includes a charger and rechargeable LiPo battery.
In your case, the Bluetooth version is a lot easier to setup and use from a computer in a smaller environment. The DFRobotShop Rover is a great learnign tool because everything is open; you can see the gears moving (and how it slows down a motor and increases its power), all the electronics and wires etc. We encourage you to tape your presentation and put it online; many teachers would love to see it.
Hope this helps,
If you determine you need additional range, XBee is the way to go. The one additional point to mention is that the DFRobot Bluetooth receiver plugs into the APC220 / Bluetooth pins as opposed to using a shield, whereas the XBee kit involves stacking the electronics. This may or may not have an impact on your decision. The sample sketch is included in the user manual’s code section and has you control the Arduino from Hyperterminal using the WASD keys. This obviously works best ifthe DFRobotShop Rover is wireless.
You are correct in that the motor controller is incorporated onto the board and is hardwired to specific digital pins. The board also has both a light and temperature sensor (just so you can start playing with sensors without having to purchase anything else), 6 blue LEDs (for effect), easy pinout for I2C and more.
We have yet to be informed of any failures, but should it happen outside of the warranty period, the basic board is still an Arduino; you can de-solder the H-bridge and add a standard motor controller (shield or other, or replace the L298). In reality, you are not restricted to using the motor controller on the board either - you can add a standard motor controller shield at any time (the L298 should receive commands but not do anything).
Hi,
The Basic DFRobotShop Rover kitcan be made autonomous, though if you want to send / receive commands, you would need to do so via the USB cable. You can always add the DFRobot bluetooth module, an XBee shield etc. if you would like it to be wireless. The DFRobotShop Rover Bluetooth kitincludes the DFRobot bluetooth module, as well as the LiPo battery and charger, while the XBee version includes an XBee shield, two XBee modules, an XBee to USB interface module and the LiPo battery and charger. A bluetooth module replaces a COM port, so just like the Arduino bluetooth, you can program the robot wirelessly.
We have found the LiPo battery and charger to be incredibly convenient which is why it was included with the two kits. One option is to purchase the basic kit and then upgrade as needed. Note that because it is a regular Arduino (with a few pins used for motor control) you can add third part products as well.
Sincerely,
Hi hardmouse,
Welcome to the RobotShop Forum. We decided to try the code on one of the rovers we have in house and it worked in under 20 seconds. We will try with the new version of Arduino shortly. The only possible source of error we can see is the choice of COM port - can you verify that you selected the right one? We note this because you connect the board and don’t verify the COM port. Instead, dsiconnect the board, see which COM ports are available, then connect the board, assign the “new” COM port (which should appear) then upload. The ON/OFF switch is connected to the H-bridge; the Arduino itself can be powered directly via the USB port. Your choice of microcontroller is correct. Is it possible to verify in your control panel which COM port is assigned to the FTDI chip? You may try to download and reinstall the FTDI drivers just in case. If this does not work, the board itself may be defective and we would be happy to do an exchange (separate the board from the base/motors since those should be working). For the two incuded sensors, you can use the AnalogInput sketch as found in the software -> File -> Examples -> Analog section.
You would need to reassign the pins to use analog pins 0 and 1.
We await your reply,
We certainly want your Rover to work, so please keep us posted if you need an exchange.
Hi,
You should be able to program the microcontroller via the bluetooth connection, and also send/receive data. Can you post the videos here? If the motors turn only when the treads are off, it could mean one of several things:
]The motor configuration is wrong and it has not been assembled in configuration C (using the center hole). Configurations A and B makes the tracks far too tight./:m]
]The battery needs to be charged or there is insufficient power getting to the motors (if you have a multimeter, you can check the voltage at the connection)./:m]
]There is something wrong with the revised code (if the default code works, then the board is fine)./:m]
]Something is preventing the sprockets from turning freely (check them by hand to see that they all spin freely)./:m]Hope this gives you some ideas,
Hi salamandergod,
Welcome to the RobotShop Forum.
We decided that since most people have a USB cable that we would not increase the price and include one, just so they can add another cable to their growing pile. Nevertheless, we do offer them separately.
The Bluetooth kit includes both the LiPo battery pack and the Seeedstudio Solar Charger. If you go to page 8/20 of the DFRobotShop Rover User Manual, you see how to connect the solar charger and the battery pack. As you indicate, if you purchased the Bluetooth or XBee kits, you don’t need the AA battery holder (which means you can add more cargo or electronics). The LiPo battery pack powers both the board and the motors, so you don’t need the AA pack or any additional batteries). The AA battery pack connects to the power input on the DFRobotShop Rover PCB and then to the On/Off switch, and subsequently the voltage regulator.
A solar panel will be able to charge the LiPo, but it would need to provide sufficient current to run the motor and the microcontroller. You may be able to use both the battery and the solar panel in unison to extend the operating time of the rover, though we suspect it will not be able to run continuously on just the solar panel because of current requirements when in operation. Nevertheless, we encourage you to give it a try and post your results!
The bluetooth is plug and play; connect it to the “APC&BLUETOOTH” port which is directly behind the motor controller (middle of the PCB) and ensure it is facing forward (towards the “RobotShop” and DFRobot logos). This replaces a serial link so you don’t need to use a USB cable for communication. If you were fortunate enough to get the V1 Bluetooth module which included the USB bluetooth dongle, it’s just a bonus; they are not “paired” and you can use whatever bluetooth device / dongle you want or have on hand. If you already have a bluetooth dongle, it should come with instructions as to how to set it up (we use BlueSoleil among others, but you can use what you want). You don’t need to modify the little swtiches on the bluetooth module, and we hope to have a user guide available soon.
We appreciate the feedback and are taking into consideration everyone’s suggestions and comments for V2 of the DFRobotShop Rover.
Sincerely,
Hi,
We appreciate the photos and if the rover is working with the AA battery pack, then the PCB is fine. Your jumper seems to be in the right location on the shield, and the battery looks to be connected properly. Consider disconnecting the AA pack entirely (use ither the AA pack OR the LiPo pack). Troubleshoot by process of elimination - remove the shieldfrom the Rover and charge it separately (the shield alone can be used as a charger and does not need to be connected to the Rover). If you have a multimeter, check the voltage of the LiPo battery to ensure it is charged or chaging (should be about 3.8V or 3.9V when charged. If nothing seems burnt or missing from the shield, then we’ll be bable to find a solution. Try the above and get back to us here.
Sincerely,
Definitely do not have both the AA battery pack and LiPo battery connected while troubleshooting. The Vin pin is voltage input to the Arduino. and the ground is automatically connected. If you find that the LiPo battery is charged and produces 3.7 to 3.9V, connect it (using some spare wire since it won’t fit directly)) to the white JST connector on the rover (ensuring again the AA pack is not connected anywhere) and re-run the program. If this works, there may be an issue with your charger shield. We await your results.
Aside from what was mentioned, there is no additional troubleshooting which can be done, and we can safely determine that the solar shield is defective and can issue an RMA (provided it is under warranty of course). The shield (except for the addition of the jumper when using it on the Rover) should be plug and play. If you would like to proceed with an RMA, please write to us in the RobotShop Support Center (exchanges and returns department) and indicate your invoice number and the product code you would like to exchange. You can also indicate this thread (copy/paste the URL).
Hope this helps,
Hi Edzilla,
A few important things to note. Did you follow the RoboShop DFRobotShop Rover Assembly Video and assemble the motor in configuration C? The motor is geared down to the point where is is difficult to move by hand, so you need not worry about that. If the board’s lights come on and you are able to load a simple program like “hello world”, then the board itself is functional. Can you provide an image of your connections between the motors and the screw terminals? If you are using the wire crimps, ensure they are crimped tightly. Also, ensure that the wires and bare motor leads are not touch the PCB, possibly causing a short circuit. We suggest powering it using the Seeedstudio solar shield and the corresponding LiPo battery. However, if you purchased the basic kit, we suggest using the AA battery pack. If you have issues with the AA pack, please use a multimeter to see if you obtain the appropriate voltage at the output pins. Next, it’s not good to “play around” with battery polarity - the connectors we chosen to connect in only one way and reversing it may dammage the board. Last, the on/off switch needs to be set to “on” in order for the motors to work. Note that the on/off swtich is only associated with the motor controller - not the microcontroller.
Keep us posted,
Hi,
The current at peak power available from the solar panel you mention is only 170mA. This may be just borderline enough current to run the rover on a level surface. It should work well to charge teh battery. Using both the battery and solar panel together may extend the operating time between charges, though it is important to note we have not tried that combination of products - we encourage you to test it and provide your results here.
Sincerely,
Hi alexis10,
Welcome to the RobotShop Forum. If the LEDs turn on when you plug in the USB port, and you are able to download the code without issue, the PCB itself is probably fine. Are you using the AA pack or the LiPo pack? Are you using the Seeedstudio solar shield? Is the battery charged? Did you turn the on/off switch to the ON position (the on/off switch connects the motors to the battery - the microcontroller is always on)? How are you using the sample code? Note that the sample code is intended to be used with Hyperterminal - if you want to use it with the Arduino serial interface, you will need to enter each letter at a time. If the LEDs turn off when you plug in the motor - you may have a short circuit or simply not enough power. Check that the wires from the motors do not touch anything on the PCB (the instructions are to cover the leads in electrical tape just in case). Also, don’t plug in BOTH the AA pack and the LiPo - choose ONE (we suggest the LiPo). Ensure that the LiPo battery is charged by leaving it plugged into the shield (ensure you plug the battery into the correct location on the shield) and that it is at 3.8 to 3.9V before using the rover.
Hope this helps,
Hi,
The USB port is not enough to power both the microcontroller and the motors, which explains why the board goes dead. Do not try to do that often because the motors are trying to take current which your computer’s USB port cannot provide. We suggest charging the LiPo battery for a few hours using the shield, then plugging it in - follow the instructions (remembering the jumper wire on the shield) and it should work fine.
Sincerely,