Bluer White

I presented a tutorial introduction at KansasFest 2010 on the Mindcraft Macrosoft programming language, a macro assembler package that allows the programmer to achieve machine language speed with a high-level Applesoft BASIC-like syntax.  Macrosoft and its companion Assembler run on you favorite 8-bit Apple II.  The presentation was well received, and several people left motivated to try Macrosoft for themselves. Don’t miss the history of Macrosoft from the author, Alan Floeter, that’s part of the presentation slides (page 11).

Ken Gagne has kindly shared a recording of my presentation and posted the slides.  Watch the presentation, buy a copy of the Mindcraft Assembler & Macrosoft, and write the next blockbuster Apple II software.

USE MACROSOFT.3.1
UEN
MUL
BEGIN
PRINT "Macrosoft Rocks."
CLEANUP
END

There’s a working Macrosoft example in the presentation slides.  Also, check out my “hello world” program in Macrosoft and with the Assembler.  Finally, don’t forget my winning KansasFest 2009 HackFest entry written with Macrosoft.

My KansasFest 2010 HackFest entry with source code is now available for your enjoyment.  This entry took second place behind Martin’s Wizardy crack.  I used Complete Pascal 2.0 with Pegasoft Draw Tools 3.1, both of which are freely available, to create my first 16-bit Apple II program.  The program displays pictures from KansasFest and asks related trivia questions.

The photographs are used with permission from Henry Courbis of Reactive Micro.  I converted the original JPEG images to GIF files on a modern Macbook then used Super Convert on a IIgs to produce packed SHR image files.

I hope some budding programmer will find the software to be a useful starting place for the next brilliant Apple II software!

There are just so many fabulous things to see and do at KansasFest that Hackfest has not gotten much attention!  Where else do you get to see the worst Apple product and a disk operating system almost twice as fast as ProDOS?

I want to include full-screen bitmapped images in my entry, and I’m figuring out how to load and display images.  The toolbox does not offer a convenient “load image from file” call so I must provide code to load, parse, and decompress the image file.  I found a CSA2 post with sample code and the Pegasoft Draw Tools package.  Draw Tools provides numerous handy drawing tools, including fades, wipes, animation, and image loading.  So, I’ve installed Draw Tools and have the sample code working.  The TML Pascal samples work well with Complete Pascal since Complete Pascal is really version 2 of TML Pascal.  Work continues …

The annual KansasFest HackFest is on!  I’ve heard rumors of Wizardy cracking and a Rockhurst text adventure.  I’m learning Complete Pascal, learning IIGS toolbox programming, and, just in case I run out of things to do, using those skills to write a graphical Apple II/KFest trivia adventure.  I have Complete Pascal running and am ready to crank out a bit of code.  Stay tuned for more …

Following the model of Eric Shepherd’s “Some Assembly Required: Hello World” article on A2Central and my last post on the Mindcraft Assembler, I’d like to present the traditional “Hello World” program for 8-bit Apple II using Macrosoft.

Macrosoft allows the programmer to achieve machine language speed with a familiar BASIC-like syntax.  Technically, Macrosoft is a macro library for the Mindcraft Assembler.

First, follow the directions included with Macrosoft to create a working disk with The Assembler and Macrosoft.  Next, just like last week’s tutorial, slide the disk into your drive and run the BOOT.SYSTEM program.  Press “E” to enter the editor.  Press “enter” once to get a “!” insert mode prompt.  Type in the following program.  Case does matter, so watch the capitalization.  Also, make sure to begin each line with a space; otherwise, the assembler will interpret your entry as a label.  Notice that, except for a few extra “boilerplate” lines, the program appears similar to BASIC.

USE MACROSOFT.3.1
UEN
MUL
BEGIN $2000
PRINT "Hello world."
CLEANUP
END


Press the “Escape” key and enter “Hello” for the “Save Pathname.”  Press “A” to assemble to program.  If you get errors, return to the editor and correct them.

Finally, press “!” to exit back to BASIC.  Change to the directory containing the HELLO program and type “BRUN HELLO”.

Following the model of Eric Shepherd’s “Some Assembly Required: Hello World” article on A2Central, I’d like to present the traditional “Hello World” program for 8-bit Apple II using the Mindcraft Assembler.

Slide the Assembler disk into your drive or run the BOOT.SYSTEM program.  Press “E” to enter the editor.  Press “enter” once to get a “!” insert mode prompt.  Type in the following program.  Case does matter, so watch the capitalization.

            ORG       $2000

COUT        EQU       $FDED         ;Apple II character out func.

            LDX       #0            ;Offset to first character
loop        LDA       msg,X         ;Get the next character
            BEQ       done          ;->Yes!
            JSR       COUT          ;Print it out
            INX                     ;Move on to the next character
            JMP       loop          ;And continue printing
done        RTS                     ;All finished!

msg         ASC       "Hello world."
            DSC       $8D
            DSC       $00

Press the “Escape” key and enter “Hello” for the “Save Pathname.”  Press “A” to assemble to program.  If you get errors, return to the editor and correct them.

Finally, press “!” to exit back to BASIC.  Change to the directory containing the HELLO program and type “BRUN HELLO”.

BlueBot brought home the Rookie Award!  Check out the classy styrene rain jacket, too.  A local authority (Peter’s Wife) observes that “Peter’s robot is awesome.”

BlueBot did well in the AVC but did not finish.  The ‘bot successfully extricated itself from encounters with rocks, sticks, dirt clods, pine needles, and curbs.  The wheels, however, ended up being too small and too slick to keep going.  The software and basic approach are sound.  Next year, BlueBot will return with better wheels, bigger motors, and a few more sensors to help detect obstacles from greater distance.

Here’s a nifty flyer about BlueBot:  BlueBot Flyer

Thank you to everybody, both SparkFun employees and other participants, who made the AVC possible.

After far too much pain and effort, the magnetic compass is integrated with the robot.  Calibration is a bit finicky, and I don’t think the SYNC signal is implemented properly.  But, the compass works, and the heading matches my mechanical compass.  Here are a few lessons learned:

1. RTFM.  Set the pin data direction (DDRQS) because inputs don’t work well as outputs and outputs don’t work well as inputs.  The QSPI hardware will halt with “mode faults” if the pin directions are wrong.  Set the PORTQS register to the inactive pin state.  The slave select pins are active low, and don’t forget that when setting the PCS bits in the COMMAND bytes.
2. RTFM.  The Vector V2Xe compass has a response timeout, and trying to write out a bunch of debug information in the middle of reading the response is ill-advised.  Also, the compass does not respond immediately, so look for the 0xAA synchronization byte.  The compass manual is, unfortunately, vague in a few areas.  The manual mentions the response delay for GetData commands but not for other commands.  Also, the manual does not give full timing specifications (e.g. setup and hold times) for the SPI bus or the SYNC signal.  The manual doesn’t say if the slave select may temporarily go inactive in the middle of a command or response.

I’m busy tweaking navigation and obstacle avoidance behaviors.  The Sharp IR range finders give false positive readings when moving into the sun, so the ‘bot can develop heliophobia.  I just finished implementing a simple low-pass filter for the IR ranges, and I’ll see if performance improves.  I’m considering the addition of tactile bumper — the IR filtering and the elevated sonar (to avoid ground reflections) make the robot blind to short obstacles.

I’m ready for the AVC.  Are you?

Here’s a new video showing off obstacle avoidance. The robot manages to avoid walls, chairs, tables, couches, and a dog (although the dog usually runs away, probably because it knows the robot’s secret world domination plans).

Much work remains, and not enough time remains.

• I’ve replaced the motors to increase torque.  The old, faster, lower torque motors tended to stall.  The new motors work well although they produce more electrical noise.  Next time I have the robot apart, I’ll add the vendor’s recommend filter caps to the motors.  As an interim solution, I limit the acceleration, which keeps to noise to a manageable level.
• The wheels tend to fall off.  That would be embarrassing during competition.  I cannot get the set screws on the wheel hubs to stay put.  I’ll drill out the hubs a bit so the wheel sit further on the motor shaft.  If that doesn’t help, I’ll try a thread locking compound.
• The micro-controller appears to radiate interference that affects the GPS receiver.  I experimented with tin-foil shielding and didn’t observe improved reception.  I added a 3.3V regulator dedicated to the GPS, and performance is now acceptable.
• The software has grown substantially.  The robot sports an interactive serial monitor.  The monitor allows configuring various parameters and saving those parameters in battery-backed RAM, which allows me to tune behaviors without the time consuming compile/load cycle.  Also, the monitor permits checking sensor values, watching raw NMEA data from the GPS, and restarting the GPS.
• Waypoint seeking and route following code is done and working.  Unfortunately, the GPS doesn’t provide reliable heading data at the robot’s typical speeds.  I’m not really surprised and planned from the beginning to include a magnetic compass, but I never got around to integrating the compass.
• The tail wheel is too small and tends to catch on obstacles.  I have several new candidate wheels in the mail.

Next up:

• Integrate the compass and update the navigation code to use the compass.
• Replace the tail wheel with something less likely to get stuck.
• Improve main wheel mounting.
• Use the buttons on the top of the robot for something.
• Implement a data logger to permit better analysis of robot performance.