You've got questions. We may have answers. Below are some of the questions we hear often.

Q: My robot is broken! What can I do?

A: Below is a document with a number of common robot failure symptoms, possible causes, and possible solutions. Take a look to see if your robot can be returned to operation quickly.

Q: Why won't CEENBoT Commander (the graphical programming software) work on my Mac?

A: Your version of Mac OSX must be at least 10.5.8, and the newest version of Java installed and made the default. Detailed instructions are here:

Q: I write programs with CEENBoT Commander on my Windows 8 computer, but I can't program my robot. When I try, I get odd and non-helpful error messages. What's wrong?

A: Microsoft Windows 8 has implemented tighter protections including requiring any drivers installed on the computer to be digitally signed, and the digital signatures must not have expired. CEENBoT Commander uses a set of open source software tools that are not digitally signed, and Windows 8 does
not NORMALLY allow installation. There is a method to enable installation of unsigned drivers, described below. We do not take any responsibility for your computer if you make these changes.

First, turn off Driver Signature Enforcement by following these steps.:

  1. Press the "Windows" key and the "X" key to enter the Tools Menu.
  2. In Tools Menu, select Command Prompt.
  3. In Command Prompt, enter:
shutdown.exe /r /o /f /t 00
  1. Click the "OK" button.
  2. System will restart to a "Choose an option" screen.
  3. Select "Troubleshoot" from "Choose an option" screen.
  4. Select "Advanced Options" from "Troubleshoot" screen.
  5. Select "Windows Startup Settings" from "Advanced Options" screen.
  6. Click "Restart" button.
  7. System will restart to "Advanced Boot Options" screen.
  8. Select "Disable Driver Signature Enforcement".
  9. Once the system starts, install the CEENBoT Commander program (including the open source drivers) as you would on Windows 7.

The install the driver after Driver Signature Enforcement has been disabled. This assumes you have already attempted to install the drivers and it did not work:

  1. Press the "Windows" key and the "X" key to enter the "Tools Menu".
  2. In the Tools Menu, select "Device Manager".
  3. In "Device Manager", right click the Unknown Device.
  4. Select "Update Driver Software".
  5. Select "Browse" my computer for software.
  6. Click "Browse" button.
  7. Browse to the folder:
C:\Program Files\Ceenbot\CEENBoT Commander\bin\avrisp_driver
  1. Select the box "Check Subfolders".
  2. Click "OK"
  3. Click "Next"

If you have a new system that came with Win 8 pre-installed, Secure Boot may have been enabled in the BIOS. The steps above, probably will not work unless Secure Boot has first been disabled in the BIOS.

Thank you to Steve Hamersky for providing this information.

Q: When I try to upload my program to my CEENBoT, the upload fails. Whats wrong?

A: We work to make uploading reliable and easy. However, uploading can be complex and subject to many problems. Here are some ideas to solve problems programming:

  • Make sure the battery is charged. The CEENBoT resets during the programming process, and during the reset the charger circuit turns off for a few seconds. Running on the battery keeps electrical power going to the robot throughout the programming process.
  • Check the programmer connections. One end of the programmer goes to your computer (Mac OSX or Windows). The other end connects to the CEENBoT controller. If any of the connections are not right, or if the programming cable is turned 180 degrees (so the cable runs past the wireless remote socket), the robot will not program.
  • Check the processor select jumper. The CEENBoT has two microcontrollers on board, and both can be programmed. A jumper next to the red and green LEDs belongs in the "Mega" position to upload your program. We do not normally recommend changing the jumper to "Tiny" and we normally would discourage programming the ATTiny processor.
  • Sometimes the AVR ISP mkII programmers go bad. If you have another programmer, try it.
  • Other programs have different software (drivers) for the AVR ISP mkII programmer. One of these programs is AVR Studio, a programming package that allows you to write software in the C programming language, has a driver that is incompatible with CEENBoT Commander. If both software programs are installed on the same computer, your computer will not be able to program a robot. Contact us for help in repairing this issue.

Q: I want to write my own programs and don't want to use the drag and drop CEENBoT Commander. What do I do?

A: You can write C programs for your CEENBoT using the Atmel AVR Studio software package, or you can use open source development tools starting with Eclipse. You will find the Atmel AVR Studio software at Atmel AVR Studio download Information on installing and configuring Eclipse, Java, WinAVR, and the AVREclipse plug-in is at:

Q: I want to purchase a replacement battery for my robot. What do I want?

A: The battery used on the CEENBoT is a standard remote control car battery, and a battery from a hobby supply store or web site with these features should work:
  • Nickel-Metal Hydride (NiMH) battery chemistry. Don't use nickel-cadmium (NiCad), as they don't last long when new and degrade very quickly.
  • 7.2 volts DC (a six-cell NiMH battery pack);
  • A "Tamaya" type power connector;
  • The capacity of the battery is rated in either miliamp / hours (mAH) or amp / hours (AH). The capacity is an indication of how much power the battery holds, and any capacity will work with your robot. The higher the mAH rating, the longer it will run without recharging. Also, the higher the mAH rating, the more it costs. We DO NOT recommend purchasing batteries from eBay as battery capacities are routinely over-rated. New robots ship with a 3000mAH battery.

You can also purchase replacement parts including the battery from CEENBoT, Inc. at

Q: I want to purchase accessories for my robot (servos, etc). Where should I look?

A: We have had success with radio control hobby web sites like Tower Hobby, Hobby King and some of the others With Hobby King, use their US warehouse, not the overseas one.

Another great source of ideas and gadgets are electronic and experimenter web sites like Adafruit, SparkFun and Robot Shop have many interesting things on their web sites.

Amazon and Ebay have lots of odd, unusual and creative items you can use in your robotic activities. If you are willing to take a bit more risk, AliExpress is much like Ebay with many direct from China sellers.

Locally, hardware stores, home improvement centers, craft stores and hobby shops have lots of great things to play with.

As a suggestion, we recommend NOT buying the cheapest servos, but look for specifications from sites like SparkFun, and find similar specification parts at discount vendors. We strongly recommend servos with metal gears, as the plastic gears don't last long. Also, servo physical size is often a direct indication of how much power they can exert, and you will need something with enough oomph to move the attachments.