This short article gives you a quick start to using the robot.ocx component to control real or virtual robots from Imagine (or other languages).
If your computer is ready to be used with Robotnacka, the first step is to create a robot object and then connect to robot through the virtual BlueTooth serial port:
new "oleobject [comname robot name r] r'connect "com4Now you can send commands to the robot as if you were controlling a turtle. Note however, that these commands will not control any turtle on the screen, they only control the robot directly. (However, if you load robot.imt, which contains class RobotTurtle, it will entangle the robot with a turtle on the screen). For example, you can issue the following commands (for a complete list, see below):
r'pu r'fd 1000 r'lt 720 ; corresponds to 90 degrees r'pd r'bk 1000
The robot is not limited to simple turtle-like movements. It can also draw circles, and arcs of almost an arbitrary radius. Drawing arcs is achieved by setting different constant speeds on both robot wheels. For example, the following command:
r'fdspeed 10 40will make the robot start moving forward, while its left wheel will be moving with a quarter speed compared to its right wheel.
l1 = 2π.(r - 90)
l2 = 2π.(r + 90)
l2 = 4.l1
________________
2π.(r + 90) = 8π.(r - 90)
r + 90 = 4r - 360
r = 150 mm
r'bkspeed 50 50will make the robot start moving backwards with half speed, and the command:
r'ltspeed 10 40will make Robotnacka draw a circle with a radius 54 mm.
180 = r1 + r2 r2 = 4 r1 180 = 5 r1 r1 = 36, r2 = 144 r + r1 = 90 r = 90 - 36 = 54 mm
r'rtspeed 0 50will make the robot turn half the speed backwards around its left wheel, which will remain at the same place.
The speed commands normally execute until you stop the robot by setting a speed 0 on both wheels (fdspeed 0 0). Alternately, you can use the combined commands, where the number of steps to perform is limited (r'fdx, r'bkx, r'ltx, r'rtx) and thus draw circular arcs of a specific length.
When moving the robot around the arena, it would be interesting to know its location. This is not possible with perfect accuracy because no robot in the World could avoid its wheels slipping on the floor surface, and no factory in the World would produce so precise robot that would not loose some angular seconds when moving forward or turning at the spot. Nevertheless, robot component keeps track of the exact estimated location of the robot. You can obtain it using the command pos. To print it to the text screen, say:
print r'pos 0It will print both the location (x and y coordinates) and the heading of the robot.
Sometimes it might be suitable to reset the coordinates to [0,0],0, and the command
r'pos 1does just that (and returns the previous coordinates as well).
The robot is equipped with 6 sensors, designed to avoid falling off the edge of a table. We can use them also to determine if the floor surface is white or black - for example, the robot can stop when it will reach some geometric figure placed on the floor. The sensor values (which are always 0 and 1 for each sensor - and these bits are packed into one 6-bit number) can be determined by getsensors operation, for example to print the current sensor readings say:
r'getsensorsThe robot can be programmed to react to a particular sensor configuration using condition command. For example:
r'condition 0 63 0will make the robot watch the edge of the table, or:
r'condition 16 0 16will make a robot that follows a black line stop when the line ends. To learn what the parameters of this command mean, and about many other commands that the robot component provides, please read the ReadMe.txt file.
| Quick robot command reference | |
| fd N | move forward N steps |
| bk N | move backwards N steps |
| lt α | turn left α steps (α / 8 degrees) |
| rt α | turn right α steps (α / 8 degrees) |
| fdspeed l r | set the speeds l, and r on the motors |
| bkspeed l r | set the speeds -l, and -r on the motors |
| ltspeed l r | set the speeds -l, and r on the motors |
| rtspeed l r | set the speeds l, and -r on the motors |
| fdx l r N | same as fdspeed, but stop after faster wheel will make N steps |
| bkx l r N | same as bkspeed, but stop after faster wheel will make N steps |
| ltx l r N | same as ltspeed, but stop after faster wheel will make N steps |
| rtx l r N | same as rtspeed, but stop after faster wheel will make N steps |
| pd | pen down |
| pu | pen up |
| getsensors | return sensor state |
| isalive | ping the robot |
| getvoltage | determine battery voltage level |
| getactivity | 1 - in speed cmd, 2 - in position cmd, 3 - idle, 4 - error |
| isdone | 1 - idle, 0 - still in position command |
| alwayswait on|off | on means that position commands return only after completion (default off). |
| drawtext text size font | draw the text of specified size and font (Borland BGI fonts) |
| textsize text size font | determine the size of the text in steps |
| pos reset=0|1 | return current position (and reset if requested) |
| moveto x y | move robot to specified location |
| condition xor and or | set the sensor condition |
| satisfied | determine condition status of the last command |
| connect port | establish connection to the robot |
| setcomparam ... | set communication settings |
| getversion | firmware version |
| getnum | robot installed capabilities |
| tone frequency duration | play tone |
| drawcalib | draw calibration image |
| calibrate ... | calibrate robot based on calibration image |
| gripper command | operate the gripper (if attached) |
| server on|off | make robot available on the net |
| portnumber num | used both when connecting to network robot and by server |
| getport | communication port where robot is connected |
| message user msg | send text message to user when networking |
| password newpswd | change admin password |
| exclusive on|off | start or stop single-user exclusive mode (when networking) |
| logoff passwd | logoff another user |
| user name passwd | specify user and password for login |
| connected | returns 1 if robot is connected, otherwise 0 |
| netreport filename | setup server logfile location |
| db ... | setup database for user registration |
| userfile filename | setup userfile location |
| adduser name pswd | add new user to userfile |
| deluser name | delete user from userfile |
| listusers | return list of users |
| wait t | wait until position command completes or t ms |
| messages on|off | allow system messages to be shown in message boxes |
| logfile filename|off | specify logfile location for replay |
| replay filename | replay commands stored in file |