07:53
technoclub
This tutorial is the easiest way in the world to give you a fast start into building robots.
Everything here is so easy, that after you have gone through it, you can make a robot in a couple of hours. Why can't you do that now?
Because there are so many little things you need to know. This is an attempt to let you know exactly all these little things, and nothing more. Fast, and based on 2 years of experience of what people need to know to get started. If you hurry, you can run through this, and be robot builder in a couple of hours. But expect to use a good weekend - Learning takes time - even though it is very easy, it just takes some time, all the little things to get to know :)
There are other "How to get started building robots" out there. This one is focusing on getting you around everything extremely fast. You need no knowledge of ... anything. And you will learn everything... well, the basics of everything ;)
Materials Needed:
1 PICAXE-28 Project Board
The 28 pin project board is like a game of Mario Bros; Fun and full of extras and hidden features, making you want to play over and again. It is an extremely good board to get you started, and it can be used for a fantacillion different projects, don't get me started :)
Male "snap off" Header Pins, at least 10 pins on a strip
Many times the boards that you buy just have holes in them, and that makes it hard to plug something in / on. One way to overcome this, is to solder wires into the holes. Another is to add these pins, so you can plug on wires, like with the servo and female headers shown below. "Why don't they just put pins in all the holes from the factory", you may ask. Well, I don't know. Maybe to give us the option. It is also possible to solder female headers onto the board, perhaps this is why.
You get these in long rows, and simply break them apart with your fingers.
3 Shorting Blocks, Top Closed
Put these over 2 pins next to each other, and there is a connection between them!
5 or more Female-Female Header Jumper cables
Yes. These are nice. When I started this hobby a couple of years ago, these where really hard to get. Now they are everywhere, and that is really good. Most things in this new robot-hobby of yours have pins (or you solder some in ;) - and by using these jumpers, you can make quick connections without soldering. Nice!
1 USB PICAXE Programming Cable
You write your robots programs on your computer. Plug this cable into the robot, and transfer the program. Unplug, and the robot runs the program by itself.
1 PICAXE-28X1 IC
This chip is a Microprocessor. That is often explained as "A computer in a chip". It can be placed in the board described above, after that, it can be programmed from your computer via the programming cable.
Your program can tell the controller to "listen for inputs", "think about them", perhaps make some calculations or look in some datas, and make outputs to something like the motor driver below.
It is chosen here, because it is quite strong, yet very easy to program, as you will see below.
1 L293D Motor Driver IC
I will describe this later, when we install it below :)
1 DIL 330 x 8 resistor array
The Yellow chip! It is very dull, just a row of little resistors. You will be using it to set your board up for servos.
1 Standard servo
A Servo is a cornerstone in most robotic appliances. To put it short it is a little box with wires to it, and a shaft that can turn some 200 degrees, from side to side.
The microcontroller can decide to where the shaft should turn, and stay there. Like go to "3 o'clock". That is it pretty handy; You can program something to physically move to a certain position. Next thing (after this project) could be to let one servo lift another servo. You would then have what is referred to as 2 DOF ("Degrees of Freedom"). But let's start with one ;)
You may wonder why my servo has that white pin, where yours might have a flat disc, a cross, or something. It does not matter, servos comes with all kinds of "servo horns". We just need something there to glue the head on to!
1 Sharp Analogue InfraRed Range Finding System (AERS) with cable
+++++++++Note:+++++++++
SHARP has discontinued their opto-electronic product lines, and as such the GP2D12 sensor described here has become obsolete afte we made this. Supply is running out everywhere, and we are working on solutions. For the time being you can (or we will do so for you, if you buy the kit) replace the GP2D12 with an GP2Y0A02YK Long Range Distance sensor. The GP2Y0A02YK's do not sense as close as the GP2D12's but they have a much farther range 20 - 150cm. We did some measurements and found that these sensors can actually reliably measure approx 16 - 180cm.
You can use the GP2Y0A02YK sensor in place of the GP2D12 to achieve better range, with not much change from the GP2D12. The pinout and voltages are exactly the same with the only change being that the GP2Y0A02YK sensors do not do as well in the close range.
++++++++++++++++++++++++
The one "eye" sends infra red light. The other sees the reflection of this (if there is one), and the unit returns the distance to the object in front of it.You give it power on 2 of the wires, and the third one plugs into the microcontroller, and tells it the distance.
1 4 x AA Battery Holder if you are using rechargeable batteries
or
1 3 x AA Battery Holder if you are using non-rechargeable batteries
(See more below, regarding batteries, and why the difference - Point is that you need as close to 5V as possible, one way or the other, and you can use something completely different in terns of batteries if you want. As long as it is just about 5 Volts.)
2 Geared motors and wheels to fit
It is very important that your motors have gears. You want a slow robot; Go for high ratios, like 120:1 or higher, as a slow robot is so much more fun in the beginning, because you can see what it is doing.
Apart from that, there is not much to say. Well, that would be, that there are many ways of moving and steering. This way of only using 2 wheels, is sometimes referred to as "skid steering". And it is worth remarking that if you'd like to add belt tracks later on, the basics are the same ;)
1 Roll of double sided foam tape
Oh yes! If there is something you cannot fix with this tape, it is because you are not using enough! It is a very, very fast way of sticking 2 items together. In fact we will be using it to make this entire robot! Depending on the make, of course, it is also reasonably easy to take apart again.
Paint stirring sticks, this tape, and a melt glue gun is the backbone for most of my fun with robots :)
1 Heat shrink tube (5 mm approx)
Sometimes you do need to solder 2 wires together. For instance the Sharp IR Range finder; It comes with straight up wires on the plug. What you do, is cut one of the female cables (above) in 2 parts, solder them together.. but before that, you cut a little piece of this heat shrink tube to slide over the place without insulation. Then with a lighter, you can quickly heat up the tube, and it shrinks to fit.
That is so much smarter than using tape ;)
Now, you may know, that normal batteries provide 1.5V. However, you may not know that rechargeable batteries only provide 1.2V!
No matter if you knew that or not, 3 times 1.5V from normal batteries, is 4.5V. If we use 4 times 1.5V we would get 6.0V, which might be a little scary to use on the Sharp, rated for 5.0V.
4 times 1.2V from rechargeables is 4.8V, which is nice and close to 5V. And then it is much cheaper in the long run. So I strongly recommend you to get some rechargeables and a charger.
Tip: The best rechargeables have the highest capacity, measured in "mAh". The 2500 mAh AA-size is a fine battery.
A Soldering iron and solder
A lighter and a cutter
Lighter for heat shrinking, cutter to.. cut.
Tip: If you want to use the cutter to remove plastic from cables, turn it this way; Imagine that you where sticking the cable right into the cutter from where you are now, into the table it is laying on. That way. And not from the table, and out to where you are. Then gently close around the wire, and pull the plastic off.
A computer with an internet connection and a free USB port
Can be Mac, Linux or PC. The software needed for this is free.
Nice-to-have tools, though not essential:
A multimeter (aka measure-thingey), a wire stripper, and a screwdriver
Everything here is so easy, that after you have gone through it, you can make a robot in a couple of hours. Why can't you do that now?
Because there are so many little things you need to know. This is an attempt to let you know exactly all these little things, and nothing more. Fast, and based on 2 years of experience of what people need to know to get started. If you hurry, you can run through this, and be robot builder in a couple of hours. But expect to use a good weekend - Learning takes time - even though it is very easy, it just takes some time, all the little things to get to know :)
There are other "How to get started building robots" out there. This one is focusing on getting you around everything extremely fast. You need no knowledge of ... anything. And you will learn everything... well, the basics of everything ;)
Materials Needed:
1 PICAXE-28 Project Board
The 28 pin project board is like a game of Mario Bros; Fun and full of extras and hidden features, making you want to play over and again. It is an extremely good board to get you started, and it can be used for a fantacillion different projects, don't get me started :)
Male "snap off" Header Pins, at least 10 pins on a strip
Many times the boards that you buy just have holes in them, and that makes it hard to plug something in / on. One way to overcome this, is to solder wires into the holes. Another is to add these pins, so you can plug on wires, like with the servo and female headers shown below. "Why don't they just put pins in all the holes from the factory", you may ask. Well, I don't know. Maybe to give us the option. It is also possible to solder female headers onto the board, perhaps this is why.
You get these in long rows, and simply break them apart with your fingers.
3 Shorting Blocks, Top Closed
Put these over 2 pins next to each other, and there is a connection between them!
5 or more Female-Female Header Jumper cables
Yes. These are nice. When I started this hobby a couple of years ago, these where really hard to get. Now they are everywhere, and that is really good. Most things in this new robot-hobby of yours have pins (or you solder some in ;) - and by using these jumpers, you can make quick connections without soldering. Nice!
1 USB PICAXE Programming Cable
You write your robots programs on your computer. Plug this cable into the robot, and transfer the program. Unplug, and the robot runs the program by itself.
1 PICAXE-28X1 IC
This chip is a Microprocessor. That is often explained as "A computer in a chip". It can be placed in the board described above, after that, it can be programmed from your computer via the programming cable.
Your program can tell the controller to "listen for inputs", "think about them", perhaps make some calculations or look in some datas, and make outputs to something like the motor driver below.
It is chosen here, because it is quite strong, yet very easy to program, as you will see below.
1 L293D Motor Driver IC
I will describe this later, when we install it below :)
1 DIL 330 x 8 resistor array
The Yellow chip! It is very dull, just a row of little resistors. You will be using it to set your board up for servos.
1 Standard servo
A Servo is a cornerstone in most robotic appliances. To put it short it is a little box with wires to it, and a shaft that can turn some 200 degrees, from side to side.
The microcontroller can decide to where the shaft should turn, and stay there. Like go to "3 o'clock". That is it pretty handy; You can program something to physically move to a certain position. Next thing (after this project) could be to let one servo lift another servo. You would then have what is referred to as 2 DOF ("Degrees of Freedom"). But let's start with one ;)
You may wonder why my servo has that white pin, where yours might have a flat disc, a cross, or something. It does not matter, servos comes with all kinds of "servo horns". We just need something there to glue the head on to!
1 Sharp Analogue InfraRed Range Finding System (AERS) with cable
+++++++++Note:+++++++++
SHARP has discontinued their opto-electronic product lines, and as such the GP2D12 sensor described here has become obsolete afte we made this. Supply is running out everywhere, and we are working on solutions. For the time being you can (or we will do so for you, if you buy the kit) replace the GP2D12 with an GP2Y0A02YK Long Range Distance sensor. The GP2Y0A02YK's do not sense as close as the GP2D12's but they have a much farther range 20 - 150cm. We did some measurements and found that these sensors can actually reliably measure approx 16 - 180cm.
You can use the GP2Y0A02YK sensor in place of the GP2D12 to achieve better range, with not much change from the GP2D12. The pinout and voltages are exactly the same with the only change being that the GP2Y0A02YK sensors do not do as well in the close range.
++++++++++++++++++++++++
The one "eye" sends infra red light. The other sees the reflection of this (if there is one), and the unit returns the distance to the object in front of it.You give it power on 2 of the wires, and the third one plugs into the microcontroller, and tells it the distance.
1 4 x AA Battery Holder if you are using rechargeable batteries
or
1 3 x AA Battery Holder if you are using non-rechargeable batteries
(See more below, regarding batteries, and why the difference - Point is that you need as close to 5V as possible, one way or the other, and you can use something completely different in terns of batteries if you want. As long as it is just about 5 Volts.)
2 Geared motors and wheels to fit
It is very important that your motors have gears. You want a slow robot; Go for high ratios, like 120:1 or higher, as a slow robot is so much more fun in the beginning, because you can see what it is doing.
Apart from that, there is not much to say. Well, that would be, that there are many ways of moving and steering. This way of only using 2 wheels, is sometimes referred to as "skid steering". And it is worth remarking that if you'd like to add belt tracks later on, the basics are the same ;)
1 Roll of double sided foam tape
Oh yes! If there is something you cannot fix with this tape, it is because you are not using enough! It is a very, very fast way of sticking 2 items together. In fact we will be using it to make this entire robot! Depending on the make, of course, it is also reasonably easy to take apart again.
Paint stirring sticks, this tape, and a melt glue gun is the backbone for most of my fun with robots :)
1 Heat shrink tube (5 mm approx)
Sometimes you do need to solder 2 wires together. For instance the Sharp IR Range finder; It comes with straight up wires on the plug. What you do, is cut one of the female cables (above) in 2 parts, solder them together.. but before that, you cut a little piece of this heat shrink tube to slide over the place without insulation. Then with a lighter, you can quickly heat up the tube, and it shrinks to fit.
That is so much smarter than using tape ;)
Also needed:
Batteries
Either 3 AA Non rechargeable, or 4 AA Rechargeable.
This robot needs 5 Volts. Mainly because the Sharp IR, really feels best on 5.0V, that's what it's made for. Motors and servo would like more, microcontroller could live with 6.0V, but keeping it simple is the core here, so we feed the whole robot with as close to 5.0V as possible. And rather too little than too much, so we make sure not to fry anything, now that this is your first robot ;)Now, you may know, that normal batteries provide 1.5V. However, you may not know that rechargeable batteries only provide 1.2V!
No matter if you knew that or not, 3 times 1.5V from normal batteries, is 4.5V. If we use 4 times 1.5V we would get 6.0V, which might be a little scary to use on the Sharp, rated for 5.0V.
4 times 1.2V from rechargeables is 4.8V, which is nice and close to 5V. And then it is much cheaper in the long run. So I strongly recommend you to get some rechargeables and a charger.
Tip: The best rechargeables have the highest capacity, measured in "mAh". The 2500 mAh AA-size is a fine battery.
A Soldering iron and solder
A lighter and a cutter
Lighter for heat shrinking, cutter to.. cut.
Tip: If you want to use the cutter to remove plastic from cables, turn it this way; Imagine that you where sticking the cable right into the cutter from where you are now, into the table it is laying on. That way. And not from the table, and out to where you are. Then gently close around the wire, and pull the plastic off.
A computer with an internet connection and a free USB port
Can be Mac, Linux or PC. The software needed for this is free.
Nice-to-have tools, though not essential:
A multimeter (aka measure-thingey), a wire stripper, and a screwdriver
© 2011 Electroclub
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