Hello!
I do not own a Basic Micro BasicATOM28-M so the following are programs to use a PICAXE-18X instead of an ATOM. The PICAXE-18X microcontroller does not have enough memory for this program:
lynxmotion.com/images/files/brata1.bas
But I want to thank Nathan Scherdin, Jim and James Frye for the above program. It helped me with servo codes needed for the PICAXE-18X BRAT.
Since the PICAXE-18X has limited memory, the idea is to store all those codes into an EXTERNAL memory such as Microchip’s I2C 24C65 leaving room for the main program in the PICAXE-18X.
Besides a PICAXE-18X and a 24C65, this demo also requires a SSC-32.
Before programming the 24C65, here is a document to help you connect it properly to the PICAXE-18X:
rev-ed.co.uk/docs/axe110_i2c.pdf
Of course, before making the BRAT walk with this demo, you will have to program the 24C65. Each of these programs needs to be run one at a time because of the memory issue and also for clarity. Here are the following programs to help you with this:
The following will program the RESET sequence codes:
'
'
' 152 BYTE PICAXE-18X BRAT
'
'
'*** SSC-32 pin assignment
'
' SSC-32 pin #13 = LH hip
' SSC-32 pin #14 = LH knee
' SSC-32 pin #15 = LH ankle
' SSC-32 pin #29 = RH hip
' SSC-32 pin #30 = RH knee
' SSC-32 pin #31 = RH ankle
'
' SSC-32 set @ 2400 baud rate
'
'*** 24C65 memory usage
'
' reset (1 line) @ 24C65 location 0000-0064 (decimal)
' walk (4 lines) @ 24C65 location 0100-0363 (decimal)
' backup (4 lines) @ 24C65 location 0400-0663 (decimal)
' turn LH (6 lines) @ 24C65 location 0700-1095 (decimal)
' bow (1 line) @ 24C65 location 1100-1165 (decimal)
'
'
' WRITE 24C65 @ LOCATION 0000-0064 RESET SEQUENCE
main:
i2cslave %10100000, i2cfast, i2cword
writei2c 0,("#29 P1500 ")
pause 20
writei2c 10,("#30 P1500 ")
pause 20
writei2c 20,("#31 P1500 ")
pause 20
writei2c 30,("#13 P1500 ")
pause 20
writei2c 40,("#14 P1500 ")
pause 20
writei2c 50,("#15 P1500 ")
pause 20
writei2c 60,("T500",13)
pause 20
endNext , program the WALK sequence codes:
'
'
' 152 BYTE PICAXE-18X BRAT
'
'
'*** SSC-32 pin assignment
'
' SSC-32 pin #13 = LH hip
' SSC-32 pin #14 = LH knee
' SSC-32 pin #15 = LH ankle
' SSC-32 pin #29 = RH hip
' SSC-32 pin #30 = RH knee
' SSC-32 pin #31 = RH ankle
'
' SSC-32 set @ 2400 baud rate
'
'*** 24C65 memory usage
'
' reset (1 line) @ 24C65 location 0000-0064 (decimal)
' walk (4 lines) @ 24C65 location 0100-0363 (decimal)
' backup (4 lines) @ 24C65 location 0400-0663 (decimal)
' turn LH (6 lines) @ 24C65 location 0700-1095 (decimal)
' bow (1 line) @ 24C65 location 1100-1165 (decimal)
'
'
'WRITE 24C65 @ LOCATION 0100-0363 WALK SEQUENCE
main:
i2cslave %10100000, i2cfast, i2cword
' *** 1st line of command
writei2c 100,("#13 p1166 ")
pause 20
writei2c 110,("#29 p1166 ")
pause 20
writei2c 120,("#14 p1166 ")
pause 20
writei2c 130,("#30 p1166 ")
pause 20
writei2c 140,("#15 p1616 ")
pause 20
writei2c 150,("#31 p1616 ")
pause 20
writei2c 160,("T1000",13)
pause 20
' *** 2nd line of command
writei2c 166,("#13 p1166 ")
pause 20
writei2c 176,("#29 p1166 ")
pause 20
writei2c 186,("#14 p1166 ")
pause 20
writei2c 196,("#30 p1166 ")
pause 20
writei2c 206,("#15 p1383 ")
pause 20
writei2c 216,("#31 p1383 ")
pause 20
writei2c 226,("T1000",13)
pause 20
' *** 3rd line of command
writei2c 232,("#13 p1833 ")
pause 20
writei2c 242,("#29 p1833 ")
pause 20
writei2c 252,("#14 p1833 ")
pause 20
writei2c 262,("#30 p1833 ")
pause 20
writei2c 272,("#15 p1383 ")
pause 20
writei2c 282,("#31 p1383 ")
pause 20
writei2c 292,("T1000",13)
pause 20
' *** 4th line of command
writei2c 298,("#13 p1833 ")
pause 20
writei2c 308,("#29 p1833 ")
pause 20
writei2c 318,("#14 p1833 ")
pause 20
writei2c 328,("#30 p1833 ")
pause 20
writei2c 338,("#15 p1616 ")
pause 20
writei2c 348,("#31 p1616 ")
pause 20
writei2c 358,("T1000",13)
pause 20
endYou also need to program the BACKUP sequence codes:
'
'
' 152 BYTE PICAXE-18X BRAT
'
'
'*** SSC-32 pin assignment
'
' SSC-32 pin #13 = LH hip
' SSC-32 pin #14 = LH knee
' SSC-32 pin #15 = LH ankle
' SSC-32 pin #29 = RH hip
' SSC-32 pin #30 = RH knee
' SSC-32 pin #31 = RH ankle
'
' SSC-32 set @ 2400 baud rate
'
'*** 24C65 memory usage
'
' reset (1 line) @ 24C65 location 0000-0064 (decimal)
' walk (4 lines) @ 24C65 location 0100-0363 (decimal)
' backup (4 lines) @ 24C65 location 0400-0663 (decimal)
' turn LH (6 lines) @ 24C65 location 0700-1095 (decimal)
' bow (1 line) @ 24C65 location 1100-1165 (decimal)
'
'
'WRITE 24C65 @ LOCATION 0400-0663 BACKUP SEQUENCE
main:
i2cslave %10100000, i2cfast, i2cword
' *** 1st line of command
writei2c 400,("#13 p1166 ")
pause 20
writei2c 410,("#29 p1166 ")
pause 20
writei2c 420,("#14 p1166 ")
pause 20
writei2c 430,("#30 p1166 ")
pause 20
writei2c 440,("#15 p1383 ")
pause 20
writei2c 450,("#31 p1383 ")
pause 20
writei2c 460,("T1000",13)
pause 20
' *** 2nd line of command
writei2c 466,("#13 p1166 ")
pause 20
writei2c 476,("#29 p1166 ")
pause 20
writei2c 486,("#14 p1166 ")
pause 20
writei2c 496,("#30 p1166 ")
pause 20
writei2c 506,("#15 p1616 ")
pause 20
writei2c 516,("#31 p1616 ")
pause 20
writei2c 526,("T1000",13)
pause 20
' *** 3rd line of command
writei2c 532,("#13 p1833 ")
pause 20
writei2c 542,("#29 p1833 ")
pause 20
writei2c 552,("#14 p1833 ")
pause 20
writei2c 562,("#30 p1833 ")
pause 20
writei2c 572,("#15 p1616 ")
pause 20
writei2c 582,("#31 p1616 ")
pause 20
writei2c 592,("T1000",13)
pause 20
' *** 4th line of command
writei2c 598,("#13 p1833 ")
pause 20
writei2c 608,("#29 p1833 ")
pause 20
writei2c 618,("#14 p1833 ")
pause 20
writei2c 628,("#30 p1833 ")
pause 20
writei2c 638,("#15 p1383 ")
pause 20
writei2c 648,("#31 p1383 ")
pause 20
writei2c 658,("T1000",13)
pause 20
endThen program the TURN LH sequence codes:
'
'
' 152 BYTE PICAXE-18X BRAT
'
'
'
'*** SSC-32 pin assignment
'
' SSC-32 pin #13 = LH hip
' SSC-32 pin #14 = LH knee
' SSC-32 pin #15 = LH ankle
' SSC-32 pin #29 = RH hip
' SSC-32 pin #30 = RH knee
' SSC-32 pin #31 = RH ankle
'
' SSC-32 set @ 2400 baud rate
'
'*** 24C65 memory usage
'
' reset (1 line) @ 24C65 location 0000-0064 (decimal)
' walk (4 lines) @ 24C65 location 0100-0363 (decimal)
' backup (4 lines) @ 24C65 location 0400-0663 (decimal)
' turn LH (6 lines) @ 24C65 location 0700-1095 (decimal)
' bow (1 line) @ 24C65 location 1100-1165 (decimal)
'
'WRITE 24C65 @ LOCATION 0700-1095 TURN LEFT SEQUENCE
main:
i2cslave %10100000, i2cfast, i2cword
' *** 1st line of command
writei2c 700,("#13 p0883 ")
pause 20
writei2c 710,("#29 p0833 ")
pause 20
writei2c 720,("#14 p0916 ")
pause 20
writei2c 730,("#30 p0916 ")
pause 20
writei2c 740,("#15 p1500 ")
pause 20
writei2c 750,("#31 p1500 ")
pause 20
writei2c 760,("T2000",13)
pause 20
' *** 2nd line of command
writei2c 766,("#13 p2166 ")
pause 20
writei2c 776,("#29 p2116 ")
pause 20
writei2c 786,("#14 p2083 ")
pause 20
writei2c 796,("#30 p2083 ")
pause 20
writei2c 806,("#15 p1500 ")
pause 20
writei2c 816,("#31 p1500 ")
pause 20
writei2c 826,("T2000",13)
pause 20
' *** 3rd line of command
writei2c 832,("#13 p2166 ")
pause 20
writei2c 842,("#29 p2116 ")
pause 20
writei2c 852,("#14 p2083 ")
pause 20
writei2c 862,("#30 p2083 ")
pause 20
writei2c 872,("#15 p1166 ")
pause 20
writei2c 882,("#31 p1266 ")
pause 20
writei2c 892,("T2000",13)
pause 20
' *** 4th line of command
writei2c 898,("#13 p0883 ")
pause 20
writei2c 908,("#29 p2116 ")
pause 20
writei2c 918,("#14 p0916 ")
pause 20
writei2c 928,("#30 p2083 ")
pause 20
writei2c 938,("#15 p1166 ")
pause 20
writei2c 948,("#31 p1266 ")
pause 20
writei2c 958,("T2000",13)
pause 20
' *** 5th line of command
writei2c 964,("#13 p0883 ")
pause 20
writei2c 974,("#29 p2116 ")
pause 20
writei2c 984,("#14 p0916 ")
pause 20
writei2c 994,("#30 p2083 ")
pause 20
writei2c 1004,("#15 p1733 ")
pause 20
writei2c 1014,("#31 p1833 ")
pause 20
writei2c 1024,("T2000",13)
pause 20
' *** 6th line of command
writei2c 1030,("#13 p0883 ")
pause 20
writei2c 1040,("#29 p0883 ")
pause 20
writei2c 1050,("#14 p0916 ")
pause 20
writei2c 1060,("#30 p0916 ")
pause 20
writei2c 1070,("#15 p1733 ")
pause 20
writei2c 1080,("#31 p1833 ")
pause 20
writei2c 1090,("T2000",13)
pause 20
endAnd finally the BOW sequence:
'
'
' 152 BYTE PICAXE-18X BRAT
'
'
'
'*** SSC-32 pin assignment
'
' SSC-32 pin #13 = LH hip
' SSC-32 pin #14 = LH knee
' SSC-32 pin #15 = LH ankle
' SSC-32 pin #29 = RH hip
' SSC-32 pin #30 = RH knee
' SSC-32 pin #31 = RH ankle
'
' SSC-32 set @ 2400 baud rate
'
'*** 24C65 memory usage
'
' reset (1 line) @ 24C65 location 0000-0064 (decimal)
' walk (4 lines) @ 24C65 location 0100-0363 (decimal)
' backup (4 lines) @ 24C65 location 0400-0663 (decimal)
' turn LH (6 lines) @ 24C65 location 0700-1095 (decimal)
' bow (1 line) @ 24C65 location 1100-1165 (decimal)
'
'
'WRITE 24C65 @ LOCATION 1100-1165 BOW SEQUENCE
main:
i2cslave %10100000, i2cfast, i2cword
' *** 1st line of command
writei2c 1100,("#13 P1800 ")
pause 20
writei2c 1110,("#29 P1200 ")
pause 20
writei2c 1120,("#14 P1500 ")
pause 20
writei2c 1130,("#30 P1500 ")
pause 20
writei2c 1140,("#15 P1500 ")
pause 20
writei2c 1150,("#31 P1500 ")
pause 20
writei2c 1160,("T1000",13)
pause 20
endNow that the 24C65 is programmed, the PICAXE-18X needs to be connected to the
SSC-32. You may refer to the following document for connector positions:
lynxmotion.com/images/data/ssc-32.pdf
In this example, pin 6 (output 0) of the PICAXE-18X is connected to the RX pin of the 3 pin header side of connector 13. Ground also has to be connected, but in this case, I did not use the TX pin.
Example of SSC-32 connector 13:
N/C —……---------------------- to PICAXE-18X pin 6 (output 0)
………|……|
………|……|
……0……0……0------ground
………0…….0
………TX……RX
Also make sure to setup the SSC-32 @ a 2400 baud rate by removing both jumpers of connector 10 for proper communication speed with the PICAXE-18X.
The following is the walking demo program:
'
'
' 152 BYTE PICAXE-18X BRAT
'
'
'*** SSC-32 pin assignment
'
' SSC-32 pin #13 = LH hip
' SSC-32 pin #14 = LH knee
' SSC-32 pin #15 = LH ankle
' SSC-32 pin #29 = RH hip
' SSC-32 pin #30 = RH knee
' SSC-32 pin #31 = RH ankle
'
' SSC-32 set @ 2400 baud rate
'
'*** 24C65 memory usage
'
' reset (1 line) @ 24C65 location 0000-0064 (decimal)
' walk (4 lines) @ 24C65 location 0100-0363 (decimal)
' backup (4 lines) @ 24C65 location 0400-0663 (decimal)
' turn LH (6 lines) @ 24C65 location 0700-1095 (decimal)
' bow (1 line) @ 24C65 location 1100-1165 (decimal)
'
'
'
'
'***** Constants/Variables *****
symbol reset = 0
symbol reset_end = 64
symbol walk = 100
symbol walk_end = 363
symbol backup = 400
symbol backup_end = 663
symbol turn = 700
symbol turn_end = 1095
symbol bow = 1100
symbol bow_end = 1165
' ***** Main *****
main:
i2cslave %10100000, i2cfast, i2cword ' Initialize 24C65 I2C
gosub brat_reset
gosub brat_bow
gosub brat_reset
for b6 = 1 to 3 ' BRAT takes 3 forward steps
gosub brat_walk
next
gosub brat_reset
for b6 = 1 to 3 ' BRAT takes 3 backward steps
gosub brat_backup
next
gosub brat_reset
for b6 = 1 to 5 ' BRAT turn slightly to the left
gosub brat_turnleft
next
gosub brat_reset
end
' ***** Sub Routines *****
brat_reset: ' BRAT resets to neutral upright position
w0 = reset
w1 = reset_end
gosub sequencer
pause 1000 ' Pause 1 second
return
brat_bow: ' BRAT bows
w0 = bow
w1 = bow_end
gosub sequencer
pause 1000 ' Pause 1 second
return
brat_walk: ' BRAT goes forward
w0 = walk
w1 = walk_end
gosub sequencer
return
brat_backup: ' BRAT backups
w0 = backup
w1 = backup_end
gosub sequencer
return
brat_turnleft: ' BRAT turns slightly towards the left
w0 = turn
w1 = turn_end
gosub sequencer
return
sequencer:
for w2 = w0 to w1 'Loops from 24C65 "w0" location to
readi2c w2,(b7) ' 24C65 "w1" locations reading previously
' stored step sequences.
serout 0,t2400,(b7) ' Sends read steps to SSC-32
' including CR (carriage return) to output 0
' @ 2400 baud rate
' Un-comment next 2 lines of code to get optional
' PICAXE programming editor terminal
' window 24C65 read values.
'sertxd ("The value of ",#w2," is ",b7,13,10)
'pause 500
next
returnThis is only a starting point of course, the rest is up to you and want you want your BRAT to do. Once programmed with the above demo your PICAXE-18X will have used up only 152 of its 2048 bytes available which should leave enough programming space for more elaborate behaviour.
I haven’t tried using Parallax’s BS2 module in the same way, but I’m certain it could be done. Other size I2C memories from Microchip could also be used in this case. Just don’t forget to re-program accordingly!
Hopefully, this will help somebody try out their BRATs in a different way!
Good luck! 