The Dreaded stk500_getsync() message…

Everybody wants flying FPV quadcopters at  some point wants to see the cool telemetry showing up on their FPV goggles.   If you are building our own, then most likely you might have bought one of the Minim OSD modules from Amazon or Ebay and watched the YouTube videos where they show how easy it is to download the MinimOSD sourcecode, launch the Arduino IDE and click the little check mark to push code down to the MinimOSD module.


Yeah right!  Nothing is ever that easy.  Chances are you will first struggle with getting the USB to TTL module drivers loaded onto your computer.  You can thank Microsoft for making this even more challenging on Windows 10 because you have to go through the process of enabling “Unsigned” drivers to be installed.  Apple is not without fault here either as I have to use a cheap USB 2.0 Hub between my MacBook Pro and any of the USB modules to get it to reliably connect.

usb to ttl

Once you get over that hurdle, you can count yourself as one of the LUCKY few that actually get to have a successful MinimOSD compile and upload, but for most they are seeing this image at the bottom of the screen of their Arduino environments:

avrdude synch timeout

I had gotten one of these and searched YouTube for an answer which pretty much told me not to worry. All I needed to do was to make sure I had selected the correct board and com port and all of my troubles would be gone.  Once again, I was not one of the lucky few.

Getting the message, stk500_getsync() means that I am unable to connect to the bootloader on the module.   The bootloader is a small application running on the MinimOSD that first looks to see if we want to upload new firmware and then if not, executes the firmware it has in memory.  If this bootloader some how gets corrupted then all you need to do is to install a new one.  You will need an AVR ISP Programmer and temporarily solder 6 pins into the 6 holes that you see that are on the MinimOSD module but are not being used.

minim with pins

Atmel Studio 7 with a “fully supported” programmer is the most consistent way to do this or you can find a much cheaper ISP programmer on Ebay and use the avrdude commands from a command line.  While this might seem like extra work, knowing how to do this is a skill set that every one flying quadcopters should learn because it will save you time, frustration and money in the long run. I will tell you that I have tried to use Extreme burner and it only led me to false reporting of success.  If you can’t use the Atmel Studio 7, then just stick to the avrdude commands in a command prompt.  The avrdude commands will let you erase the module and let you upload a clean stk500v2 boot loader from your Arduino environment.  With that said, try to install the Atmel Studio 7 IDE to make your life easier.


iPhone (or Samsung) and the Walkera Runner 250

I have written two books on the Walkera Runner 250s, the Walkera Devo 7 Configuration Guide and the MultiWii 2.4 for the Walkera Runner 250.  I wrote those books out of frustration, first on the Devo 7 Transmitter as it is incredibly hard to understand the Users Guide.  While the manual is written in English, it is clearly a translated English and sometimes the translation does not come across as it should.  I know see how other countries are challenged when they have to read English translations.  I wrote the MultiWii 2.4 for the Walkera Runner 250 because the factory firmware was so bad it basically made the Runner 250s into lawn darts and very expensive ones at that.

Screen Shot 2016-05-26 at 7.06.24 AM


I am starting to see people use the MultiWii 2.4 for the Walkera Runner 250 and upgrade their quadcopters to the latest firmware.  One person, Mikerman50 on YouTube, in particular has posted a cool video of him connecting his Runner 250 up to a the HM-10 Bluetooth Module and is now able to have complete control over his quadcopter with a MultiWii GUI on his Samsung S4.  I did some testing as well with an application that I installed on my iPhone so you can get MultiWii GUI applications on the smart phone of your choice.

MultiWii 2.4 as what is called the MultiWii Serial Protocol and you can actually program GPS Waypoints into the quadcopter for an automated flight.  You can also have several PID profile settings so that you can tune your quadcopter for a racing or a more gentle flight for aerial photography.

I am looking forward to more adoption and more experimentation by the readers.



PIDs Made Easy….

We have been playing with the Arduino environments and Quadcopters, especially the Walkera Runner 250s.  Before my Small Business Servers were blown up by the Aabaco Team, I had several blog postings on these quadcopters so I apologize if this is a repeat for you.  The subject of PIDs for these devices (and industrial controls) can be very confusing for so many that I had decided to create a simple video that makes it super easy to understand.  For example, most people’s eyes glaze over as soon as you say the words, Proportional, Integral, and Derivative.  If you are trying to explain these control loops for the quadcopters, you have lost them before you even try to speak the fourth word.  The designers of MultiWii, Cleanflight, Baseflight and other flight control systems have spent untold hours on creating super easy GUIs to configure these parameters but without the user/operator understanding what they are configuring the end result is not favorable.  In the simple tutorial, I use driving a car as an analogy and put these “complex” terms into a context that is easy for anyone to understand.  Feedback is appreciated.


Blog Restart…Again…

What a challenge it has been lately over keeping this blog up and running.  If you have made it this page from one of the links that I had posted around on some of the quadcopter forums, you might notice the article that you were looking for is not up here.  That is because on June 1st, I got an “Urgent Email” from Aabaco telling me to call them as they had an emergency situation with my site and they had to take me off line.

Aabaco notice

As you can see, they did not provide any details.  Thinking that my auto pay with the credit card failed, I quickly checked my credit card and found they had been paid a few days ago.  So I called them and they told me that had detected malware on my website and that I was to “FTP” all of the files from the website directories and scan them with one of my scanners.  I happen to know a little bit about malware and how it behaves, so I tried to explain to them that even if I went through that process that the malware issue would not be resolved.  What was even more interesting is that had actually locked me out of the account billing/administration portal.  Trying to get more details so an effective remediation could occur, I asked him for the files that were associated to the malware event that was detected.  If you guessed where I am going, yes…you guessed right.  He could not answer.  I told him there were so many real and effective steps that could be taken that would be a better use of time than me to go through a silly exercise that would have no effect on the infected server.  You might have also guessed, that I have moved my cloud based services to another provider.  Sadly, I had been with the Yahoo Small Business Services for a long time and unfortunately as Yahoo spins out their lines of businesses, they are not checking for competency as a requirement for the business transaction.  That is one massively large data center where cyber attackers will be able to launch cyber attack campaigns without the risk of being stopped.  I am incredibly confident that FTP does not have the capability to remove any malware.   Now that I am done venting, we can get back to real topics that are more interesting!

One last comment, as required by my employer.  The comments and opinions are MY OWN and in now way represent any company I may be associated.