Let's Make Robots!

Simple whisker bot

simple avoidance robot
robot1_003.AVI2.72 MB

Well I have finally started my first bot for this site.


This is basically a re-build of a robot I made around a year ago, using the Picaxe School experimentor board, using an 08M chip. I have now purpose built on veroboard a new circuit allowing simpler plug-in of components.  Drive is by two modified servos and detectors are two long armed micro switches.

Finished work late last night but did not function correctly.  Thinking about it I came to the conclusion I have left out a couple of pull-up resistors off and the microswitches are only being seen as on.


Don't have internet at home so photos will come later.  I also don't have video capability :(


Once this is working correctly the next stage is to modify it to use sharp IR distance module.  THe real challenge is in using the 08M to the max!



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Not sure if I should call this robot 2 or not.

I have now changed the sensor to a servo mounted Sharp IR module and checking distance rather than physically bumping into things.  I still have one input pin available for use

I was wondering how do you make an input on the picace 08M high? I know the code goes like this "if pin3 = 1 then" but what does pin 3 need to be connected to to be high?

The input pins will be looking for a logic level voltage if you are using a digital input.  If you feed your PICAXE with 4.5V, you don't want to exceed that. Something close or equal to 4.5V will be read as a high input. If you are powering the PICAXE with 5V, you can go as high as that. It would be potentially dangerous to exceed the supply voltage on your logic input.

You should use a 10kohm pull down resistor between the input and ground to prevent the input from floating high when the input is open (like if you have it connected to some sort of switch).

Page 57 of the PICAXE manual describes basic input/output connections.


I was using a microswitch connected direct from +ve to the pin, with a 10K reisistor from pin to Gnd.  While the switch is open the resistor pulls the logic signal to Gnd (LOW),  closing the switch changes the signal to +ve (HIGH)