I'll be working on adding the following features to the firmware:

• Non-linear stick response for more subtle movements near center
• Calibration routine that utilizes a correction in EEPROM

[email protected] http://www.smbaker.com/

This is a custom controller for the Atari 5200 vintage gaming console. The 5200's original controller do not self center, which is consider by many to be a considerable drawback to the controllers. The fire buttons are also mushy, and the controller is generally unreliable unless rebuilt.

So I made my own.

The microcontroller is an ATTINY85.

This is the workflow I used when programming from windows, using a TL866 programmer. The TL866 is the style programmer where you remove the chip from the pcboard and insert it into the programmer. Make sure to program both fuses.hex to the fuses, and 5200controller.hex to the program memory.

This is the workflow I used to do in-circuit serial programming from Ubuntu, using a usbasp programmer. The advantage of this workflow is that no ICs need to be removed from the pcboard. Only revision 0.9 and above of the pcboard have the ICSP header. You may also be able to use a windows version of avrdude instead of using ubuntu. I have not tried windows. The following two commands will program the uses and the flash:

make fuses
make flash

This was the initial version of the pcboard, eight boards sold to about a half dozen people. Notable limitations are that this revision does not have an ICSP header, and must be programmed using an external programmer (i.e. TL866).

There are also three solder jumpers for design purposes that needed to be soldered. SJ2 and SJ3 were two pin jumpers, just solder them across. SJ1 was a three-pin jumper that should be soldered on the two rightmost pins.

This was the second version of the pcboard. New features include:

• Added big button footprint. These are available at sparkfun.
• Eliminated solder jumpers, they were only present for design debugging.
• Eliminated pot reference V jumper, only present for design work.
• Added reset button and pullup. It's unnecessary. Possibly could be used as a "config" button, but currently unimplemented in the code.
• Change tactile button footprints. They were slightly too big before.
• Added JP2 pot CS jumper and pullup. The idea was this could be removed for ICSP programming if having the digipot in circuit presented a problem. It doesn't appear to be a problem, so always leave it populated.
• Added ICSP HDR, for in-circuit serial programming.

Ben Heck has a similar project, in his video "Atari 5200: Making a Better Controller" that demonstrated the technique of using a microcontroller and digital pot to do the potentiometer scaling.