Example BASIC Stamp II Program
This program, which can run on a BASIC Stamp II controller, makes motor 1 gradually
speed up, then slow down, then speed up in the other direction, and then slow down
again. For the code to work, pin 15 must be connected to the reset input (‘1’), and pin
14 must be connected to the serial input (‘2’). The interface code should look similar in
other programming languages; the description below should help you in understanding
the code and, if necessary, in translating it to other languages.
On line 1, the 8-bit variable
speed
is declared for later use. The motor controller is
then reset by a low-going pulse on pin 15 (lines 2 and 3).
The first
for loop
on lines 4-7 causes motor 1 to gradually speed up. The serial output is
created by the
serout
statement on line 5. The first parameter, 14, specifies the pin
number through which to send the serial signal. The next parameter,
32
, sets up the
serial characteristics to be 8 bits with no parity, non-inverted, at a baud rate of 19200.
The four numbers in square brackets are the data to be sent, and they correspond to the
four control bytes for the motor controller. The first two bytes should always be
$80
and
0
. The second
0
makes motor 1 go backward. The speed variable, which increases
every time through the loop, is the only part of the command that changes, and that is
what makes the motor gradually speed up. The
pause
statement on line 6 causes the
program to wait for 20 ms (0.02 seconds) before sending the next command.
When the first loop ends, the motor is set to its full speed of 127. The second loop on
lines 8-11 slows the motor back down by sending speeds from 127 down to 0. The next
two loops on lines12-19 then repeat the process, except for the parameter value of
1
in
byte three, which causes motor 1 to spin forward.
1
speed
var
byte
2
low 15
'reset motor controller
3
high 15
4
for speed = 0 to 127
5
serout 14,32,[$80, 0, 0,speed]
6
pause 20
7
next
8
for speed = 127 to 0
9
serout 14,32,[$80, 0, 0,speed]
10
pause 20
11
next
12
for speed = 0 to 127
13
serout 14,32,[$80, 0, 1,speed]
14
pause 20
15
next
16
for speed = 127 to 0
17
serout 14,32,[$80, 0, 1,speed]
18
pause 20
19
next
10
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© 2001
http://www.pololu.com/
