28125 Parallax Inc, 28125 Datasheet - Page 162

• Manufacturer Part Number: 28125
• Description: TEXT ROBOTICS
• Manufacturer: Parallax Inc

Specifications of 28125

• Title: Robotics with the Boe-Bot
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Not applicable / Not applicable

familiar code blocks in subroutines for each basic maneuver. Each maneuver is given a
one-letter code as a reference. Long lists of these code letters can be stored in EEPROM
and then read and decoded during program execution.
repeating long lists of subroutines, or having to change the variables before each
command.
This programming approach requires some new PBASIC instructions: the
and
trying out an example program.
Each of the basic maneuvers is given a single letter code that will correspond to its
subroutine: F for
Complex Boe-Bot movements can be quickly choreographed by making a string of these
code letters. The last letter in the string is a Q, which will mean “quit” when the
movements are over. The list is saved in EEPROM during program download with the
DATA
Each letter is stored in a byte of EEPROM, beginning at address 0 (unless we tell it to
start somewhere else). The
EEPROM while the program is running. These values can be read from within a
DO…LOOP
The
letter. The
Notice that each time through the loop, the value of the
one. This will allow each letter to be read from consecutive bytes in the EEPROM,
starting at address 0.
The
circumstances. The
certain condition occurs.
READ
address
directive, which looks like this:
DO…LOOP
DATA
DO UNTIL (instruction = "Q")
LOOP
like this:
and
READ address, instruction
address = address + 1
' PBASIC code block omitted here.
instruction
variable is the location of each byte in EEPROM that is holding a code
SELECT
command has optional conditions that are handy for different
Forward
DO UNTIL (condition)
...
CASE
DO WHILE (condition)
, B for
variable will hold the actual value of that byte, our code letter.
"FLFFRBLBBQ"
READ
...
ENDSELECT
Backward
command can then be used to get this list back out of
commands. Let’s take a look at each before
, L for
...
LOOP
Left_Turn,
...
LOOP
allows the loop to repeat until a
address
allows the loop to repeat only
This avoids the tedium of
and R for
variable is increased by
DATA
Right_Turn.
directive,
GOSUB