Let's make robots - our first robot

Als Fan von Hobby-Robotik und dem Make Video Blog von Frits "fritsl" Lyneborg, hatte ich für unser wochenendliches Basteln den "Start here"-Robot der Robo-Seite letsmakerobots.com ausgesucht. Philipp und ich haben ihn dann auch gebaut, ging problemlos von der Hand - das Tutorial ist echt gut zum durcharbeiten.

Der Roboter funktioniert wunderbar - wie beschrieben. Un hübsch ist er geworden (siehe Fotos). Lediglich ein leichter Linksdrift bei Geradeausfahrt. Den haben wir über einen kleinen Trick im Code (siehe unten) korrigiert, natürlich parametrierbar ;-). Die Drift scheint sich nämlich mit abnehmender Akkuladung zu verändern...

 

Unser einfacher Code funktioniert ganz gut, sodass der Robo auch aus Ecken wieder rauskommt:

' ----------------------------------------------------------------

' lmr my first robot first test program
symbol dangerlevel = 80 ' how far away should thing be, 

                        ' before we react
symbol turn = 200 ' this sets how much should be turned
symbol servo_turn = 700 ' this sets for how long time we should

                        ' wait for the servo to turn befor we 

                        ' measure distance
symbol rightdelay=10 ' after rightdelay times calling nodanger, 

                     ' turn only left wheel (drift correctiion)

' ----------------------------------------------------------------
' initialisation stuff
gosub totalhalt    ' initially stop and turn head forward
b3 = 0    ' variable b3 is used to keep track of how often

          ' "nodanger" has been called
' ----------------------------------------------------------------
' main loop
main:
    readadc 0, b1     ' read how much distance ahead
    if b1 < dangerlevel then
        gosub nodanger     ' if nothing ahead drive forward
    else
        gosub whichway     ' if obstacle ahaed then decide which way is better
    end if
goto main
' ----------------------------------------------------------------
' including drift correction by stopping right wheel for 

' one cycle after nodanger has been called rightdelay times
nodanger: ' combination to make the robot drive forward
    if b3<rightdelay then
        high 4 : low 5  : low 6 : high 7
    else
        high 4 : low 5  : low 6 : low 7
        b3=0
    endif
    b3 =b3+1
    return
' ----------------------------------------------------------------
' looking and deciding which way to turn
whichway:
    gosub totalhalt     ' first stop!

    ' Look oneway
    gosub lturn     ' look to one side
    pause servo_turn     ' wait for the servo to finish turning
    readadc 0, b1
    gosub totalhalt

    ' Look the other way
    gosub rturn     ' look to one side
    pause servo_turn     ' wait for the servo to finish turning
    readadc 0, b2
    gosub totalhalt

    ' Decide which way
    if b1 <= b2 then
        gosub body_lturn
    else
        gosub body_rturn
    end if
    return
' ----------------------------------------------------------------
' turn robot right
body_rturn:
    high 4: low 5 : high 6 : low 7
    pause turn : gosub totalhalt
    return   
'-----------------------------------------------------------------   
' turn robot left
body_lturn:
    low 4 : high 5: low 6 : high 7
    pause turn : gosub totalhalt
    return
' ----------------------------------------------------------------
' turn head right
rturn:
    servo 0, 100
    return
' ----------------------------------------------------------------
' turn head left
lturn:
    servo 0, 200
    return
' ----------------------------------------------------------------

' stop motors and head forward
totalhalt:
    low 4 : low 5 : low 6 : low 7
    servo 0, 153
    wait 1
    return