This is in response to a previous error and also to make sure that parallel data lines to multiple LCD modules would work. I haven’t built the whole circuit but enough to conferm that it will work. Earlier I posted a schematic if a single line LCD module that had pin 3 grounded and it should have been tied high. Here’s a picture of what I wired up:

           

And here is a schematic of a Logochip and 3 LCD Modules wired up to it:

                    

And here is some code that sets up the Logochip and initializes the LCDs and prints aome characters on each LCD.

                           

Here are some links to more useful information on the LCD Modules

        A real crummy copy of the manule (LCD-111)

       More info than you want to know about the LCD controller

      A site with other applications using this LCD display

          You can make any sort of flexible joint move with a little gear driven motor out of a toy robot or car.  Just wrap some fishing line around the drive wheel and then thread it up and around the joint. You can run one string through several joints. Here I made a worm out of sections of pink foam plastic and then taped them together. 

Click the picture to see it work.

                       

     Imagine a little nest with a baby bird in it flitting around anxious for mom to come and drop a worm. This is a really cleaver use of a magnet.

                        

    Attach the magnet to the shaft of a toy motor with some epoxy and then attach a flat head screw to the magnet. Try to keep the screw straight with the motor shaft. You could use a toy gear motor if you don’t want it to flip around so fast. Mount the motor on a base and point it at an angle towards the top of a rod which is also mounted in the base. Now I just made a bird as an example. There are lots of things you could have bob around at the top of the rod. Make some kind of pivot joint at the top of the rod and then wind a steal wire all around from that point down to the motor.

My explanation won’t do it justice. You’ll just have to see the video.

    Here’s another easy way to do something fun. And I know my friend Tab really likes noise. Take a toy motor and attach a short wire across the shaft like a “T”.  You could use glue or tape or here I used a peice of plastic rod. Then bend loops on both ends of the wire. Throught those loops make rings of wire that dangle like chain links. So as the motor spins the links swing out.

               Now the fun part. Mount the motor into some foam plastic. Then around the motor you can put steal or aluminum rods or tubing that will have jingle sound when the motor spins. Or you could use wood or plastic that will clatter.      Click this picture to see the movie.

                                 

    When you need to do a lot of pushing and pulling use a motor and a screw.  The tricky part is attaching the screw to the motor so that it doesn’t wobble too much but sometimes that can be a good thing. Here we have a butterfly made of red craft foam sheet suspended three wires. A wire attached to each wing and one in the middle. The middle wire is connected to a nut on the screw that goes up and down as the motor turns forward and backward.

Click the picture below to see it work. Just imagine a whole flock of these.

                     Here’s a simple fun idea for a kinetic art. Take some wire and wind it around a post or a cone or any shape. Then mount the bottom to a base and attach a small electric motor to the top. craft some sort of flower and hook it to the motor shaft off center, so it will wobble when it turns. Connect a bettery to the motor lead wires and have fun.

                        

Its really fun. Click the picture to watch the video.

I know it sounds awful in this day and age to be using slaves but Logochips don’t really mind that much. There are a couple of groups that are considering multiple Logochips and here is a suggestion of how that can be done.  You can do something really easy by using the built in serial comm ports (portc 6 and portc 7). Here’s a brief schematic.

                               

The program that goes in the master is slightly different than the program in the slaves in that the slaves have to keep their mouths shout until spoken to by the master otherwise the master won’t know which slave is doing the talking. So here’s the Logochip software programs.

   Master:    Master1                   Slave: Slave1 

        

Pulse Width Modulation (PWM) as it is used in electronics is the greatest thing since sliced bread.

 

What it allows us to do is regulate the flow of energy with out wasting so much of it. In the early days if you had a 12 volt battery and you wanted to drive a 6 volt lamp you could use a transistor to regulate the voltage down to 6 volts but half of the energy was wasted as heat in the transistor. PWM uses the adveatage of time. A 6 volt light buld or a motor or many other devices can actually run at 12 volts just not for a long time. So we take advantage of that by pulsing. For instance, having the lamp on for 1/2 of a second and then off for 1/2 of a second would be like delivering 6 volts for one second. Of course you could call that blinking but if you speed that up about 100 times and do it at a frequency of 100 Hertz it’s so fast you can’t see the blink. Whats more the filiment of the light buld doesn’t have time to heat up to the 12 volt level so it dosen’t know the difference eather. It thinks its running at 6 volts. Caution - results may vary depending on the type of lamp your using but negative effects can be reduced by adjusting frequency and duty cycle (on and off time).

What about the transistor? Yes there is still a transistor involved but idealy it is working just like a switch. When it’s off there is no current flow and no power lost. And when it’s on all the current goes through it to the lamp and none is lost in the transistor (switch).

Here are some cleaver links I found that might help.

http://www.cpemma.co.uk/pwm.html

http://www.uoguelph.ca/~antoon/circ/pwm555.html

http://www.acroname.com/robotics/info/concepts/pwm.html

     

     The technique involves three parts: One, an oscillator circuit that uses a metal plate as the capacitor that effects the frequency. Two, a frequency divider that averages out all the garbage that might be picked up by the metal plate. and Three, a circuit that detects changes in the average frequency.

                                       

 Here’s a rough schematic using a very simple circuit. In the schematic I have it lighting an LED but this could go into the Logochip or another circuit.

I have data sheets for the two Integrated Circuits used in the circuit here:

           the CD40106      and the CD4040

I’m getting the hang of some of this linking pictures and movies in blogs.

This is a Logochip driving a stepper motor and relay coil to play a xylophone.

Here’s the Logochip code that I showed you in class.

And a schematic of the drive circuit and motor.

And just for kicks watch the  video .