Robotics

The monocore capacitor is for positive feedback for fast switching between the two motors and to slow down and avoid high frequency oscillations.

R2 together with C2 limits the maximum frequency of the monocore and motor drivers when the light is bright and the sensors are equally lit

R3 together with C2 sets the minimum frequency of the waggle even in the complete dark which is more interesting than twirling endlessly in a circle.

Having said that, maxibug is not perfect: it churns its wheels while feeding and does not back out of the feeding station when full. CD MaxiBug v5 uses just a few more parts but has powerful and efficient motor drivers, its motors are off while feeding, and it backs up when full.

The CD Maxibug v5 uses just one 74AC240 chip

When light shines on the LDR, it has low resistance and allows current to flow.  When light does not shine on it, the LDR has a very high resistance, and a much smaller current will not flow through it.

To effectively use your Sharp IR Range Finder, you must have a voltage output versus distance chart to reference from.

One major issue with the Sharp IR Range Finder and that is going below the minimum sensor range. This is when an object is so close the sensor cannot get an accurate reading, and it tells your robot that a really close object is really far.

Another issue is the high narrowness of the IR beam. In reading sharp details and getting high accuracy, a thin beam is ideal. But the problem with a thin beam is that if it is not pointed exactly at the object, the object is therefore invisible.

A more advanced use for the Sharp IR Range Finder is to do mapping. To do this, you need at least one Range Finder, and at least one non-modified servo.

The sharp IR can be used as a quick and easy front non-contact robot bumper on your robot. Just place two IR devices in front of your robot and cross beams as shown. Ideally you would perfer to use rangers that have wider beams. Note: A single sonar can do this job just as well.

For example, a box in front of your robot might appear like this: 0 0 0 0 0 106 120 124 121 109 0 0 0 0 0

When ALI bumps into something it will go backward for a short time and then go forward in another direction, so they will find their way all alone.

The first one is a light seeker and the second one is a line follower. This version I like very much.

When you are making the line follower you need to place the small light bulb. The light seeker doesn't need it.

When bumbing into something it can also reverse for several seconds. The time of going reverse can be changed. I've used 2M2 and 3,3 uF, this will give a reverse time of about 5 seconds

For the LED’s you can almost use any type or color, I used red ones 5 mm.

When you "power on" Bully it will first go backwards for some time. After a few seconds it seems that it doesn’t know what to do, it looks like it’s shivering. Then it starts of going to the brightest lightspot it can see, first slowly and then like "in a hurry". When it reaches the lightspot it makes turns which make it look like it’s happy! In the time doing all this stuff, each bump into a obstacle makes it move backwards for a few seconds. The time doing this can be changed with the 10 uF elco. Smaller means less seconds and bigger means reversing for more seconds.

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Suppose your gearing ratio is 3/1. This would mean you would multiple your torque by 3 and your velocity by the inverse, or 1/3.