The Maximite Computer

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The Maximite Computer

Author
Ron P
February 6, 2012

The Maximite Computer

The Maximite computer is a single chip computer running mmBasic from its own ps2 keyboard and VGA monitor. It can be programmed locally or remotely, via USB. It has composite video out also, so will work with a TV or any small screen of your choice. For example backup or headrest LCD monitors, from 3.5 inches on up…Once you have your program it can be stored in the onboard SD card.

Flavors

The Maximite comes in several versions, The Maximite, the Mini Maximite, the CGMMStick, the UBW32, and the Duinomite. You can, of course, also build your own. You can make your own circuit board or make a homemade mini, a 10 dollar chip and a 1 dollar break out board. The downside is you need a PicKit 3 to install the bootloader on the chip. Once you have this, then all future upgrades and programming can be done over USB.

Programming

Blink LED

Programming is done in MMBasic
Programming can be as simple as…

START: Setpin 11,8 ‘make pin 11 a digital output pin
pin(11) = 1 ‘turn output high
pause 500 ‘delay for 500mS
pin(11) = 0 ‘make output low
pause 500 ‘delay 500 mS
GOTO START

Example

Here is an example Maximite running a unipolar stepper motor. I was lucky enough to find a Maximite EV. The EV is a stripped down version, lacking a PS2 connector and monitor connector. It was simple enough to install the missing connectors as the pads were on the board.

The code being run in the video is from Bob Devries. It is for an unusual stepper and the sequence does not work on a standard stepper. Nor does the code in the Extreme Circuits, stepper Motor article, as linked to on Geoff’s site, work properly.

Fortunately a friend helped me with the code, he has corrected the Silicon Chip (Extreme Circuits) code and made improvements to Bob Devries code to include a start/stop function on “Q” and half stepping controlled with ”H” and “N”.(not shown in the video) Note: Many of the posted code examples have line numbers. However after version 3, line numbers are not required.

6 volt 200 step stepper running on 12 volts and dropping resistors

Graphics

The Maximite will run a standard VGA LCD monitor, TV, or for a dedicated project even a 2 X 16 LCD.

But where the Maximite really shines is with MMBasic, it does graphics. So you can have a custom screen with graphs in real time, Check out Glenn Littleford’s Back shed site for a wonderful example…

Code Examples

Download file
Blink led

This is the 'basic' basic

Download file
Silicon Chip

This is the corrected Silicon Chip file with line 60 changed to '9,2'. A '1'(analog) may run in some cases but wouldn't on mine

Download file
Bob Devries

This is close to the original Bob Devrie's code as shown in the video.

Please note that this has been presented as a simple project using a stepper motor. But in actual fact there are timing errors in the stepper codes that can not be overcome with this simple code.