To write program code for the various microcontrollers used by the blimp a C to Hex cross compiler is used. This software is provided by HI-Tech and is called PICC. Provided with this compiler is a Dos based program that allows code to be downloaded to the microcontroller via a RS232 Serial Port. This is very useful as once the bootloader section of code (also provided by HI-Tech) has been downloaded once via a programmer, further code updates can be made without removing the chip from the board, or in this case, even attaching a cable to the robot. The provided software works very well when the communication channel is a fixed wire, but becomes less useful when this is replaced with a radio link as errors become more frequent. The errors are detected by the supplied program but it then exits without trying to resend the data. Also, all program options are controlled from the command line and have to be entered every time a download is required. These limitations, along with others lead to the development of a windows based downloader, named Bootdown Pro.

The screen capture above shows Bootdown Pro on start-up. All available options (File Name, Comm Port, Baud Rate, etc) are stored within a configuration file and automatically set to the last used values when the program is loaded. Bootdown Pro is supplied with a help file accessible from the Help Menu, and explains all of the options and the values in detail.

Bootdown Pro can be downloaded here. Once the zip file has been copied to your computer, create a new directory to store the files and unzip the contents into this. The program is then started by double clicking on the file 'Bootdown Pro.Exe'.

The program is written in Borland C++ Builder, and should you be interested, the source code can be downloaded by clicking here.