arduino board help plz

[robonoob]

hi
i wanted to ask that could anybody plz draw a schematics to make a obstable avoiding robot if i use this arduino board :http://www.sparkfun.com/commerce/product_info.php?products_id=666&action=add_product# , 2 servo motors, and 2 infrared sensors...
and i also want to know that do i have to buy a cable to connect this board to my computer? or can i put this board directly to my comp? and if i have to buy the cable then could you recommend me a page where i can buy it (and if its possible to make 1 myself then just tell me i have 2 USB plug's that i could connect to eachother )

PS:i wanted to ttell you that its my first robot so i'd appreciate if u keep it as simple as possible :D
PSS: oh and what software i need to use for this project...(as i said its my first robot, so i dont know absolutely anything about programming )

[Ro-Bot-X]

So you need to buy this Arduino board: http://www.sparkfun.com/commerce/product_info.php?products_id=666, a usb cable: http://www.sparkfun.com/commerce/product_info.php?products_id=512 a break away pin header: http://www.sparkfun.com/commerce/product_info.php?products_id=116, 1 or 2 IR sensors: http://www.sparkfun.com/commerce/product_info.php?products_id=242.
The board needs a battery holder with a round power jack connector that I didn't find on their site.
You will also need 2 servos modified for continuous rotation. Optional, a standard servo to scan the IR sensor.

[Fredrik Andersson]

and i also want to know that do i have to buy a cable to connect this board to my computer? or can i put this board directly to my comp?

Hi,
I like that you have picket the arduino board. I'm a fan of it!

What do you mean by directly to the computer? I thought a cable was pretty directly ^^ Well, yes, you'll need a cable, featuring a type B contact. You could make one yourself, but i do recommend you buying one. It's much safer and easier, and probably just as cheap.

What does the infrared sensors look like? Is it one of those Sharp IR range sensors (with a 3 pin connection like the servos).
Do you have a breadboard or something you could solder to? You could end up having a hard time connecting everything to to singly the arduino pins. The arduino board doesn't have a neat connection line with pairs of three (I/O pin, +V, and ground). I made a application board myself featuring such an connecting line with a prototyping pcb. Basically, you need to connect the servos to an Digital I/O pin (white, yellow or orange wire on the servo), +V (red wire on servo) and ground (black wire on servo).

[robonoob]

So you need to buy this Arduino board: http://www.sparkfun.com/commerce/product_info.php?products_id=666, a usb cable: http://www.sparkfun.com/commerce/product_info.php?products_id=512 a break away pin header: http://www.sparkfun.com/commerce/product_info.php?products_id=116, 1 or 2 IR sensors: http://www.sparkfun.com/commerce/product_info.php?products_id=242.
The board needs a battery holder with a round power jack connector that I didn't find on their site.
You will also need 2 servos modified for continuous rotation. Optional, a standard servo to scan the IR sensor.

well i have IR sensors from  old mouses... so i can use them? and also what do i need the pin headers for?
fredrik do u mean that i have to solder some things? i was hoping that i can do it much easier... and the ir sensors(IR LED's)have 2 pins...(http://en.wikipedia.org/wiki/Image:Mouse-mechanism-cutaway.png)
PS: oh and i am still wating for the schematics that includes ALL the parts i will need...

[Ro-Bot-X]

As I have told you in the other post, those mouse IR LEDs and IR fototranzistors you can use for line following or wheel encoders. Read the tutorials and you will see.

The sensors from the link that I gave you are Sharp IR Distance sensors that you can't replicate with mouse parts.

The pin header you need to connect the servos and sensors to the Arduino board. And yes, you need to solder wires to these pins. Or, you can get some Jumper Wires http://www.sparkfun.com/commerce/product_info.php?products_id=8431

You want to use salvaged parts but not to solder anything??? Those salvaged parts need to be unsoldered anyway... I guess you can use a breadboard... in this case you need the Arduino Proto Shield http://www.sparkfun.com/commerce/product_info.php?products_id=7914 and a small Breadboard that you glue (it's self adhesive) in the middle of the Proto Shield: http://www.sparkfun.com/commerce/product_info.php?products_id=7916

If you want to do it the easy way (no soldering involved) you need more money to buy a complete robot kit like the Parallax Boe-Bot or Lego Mindstorms NXT.

[robonoob]

As I have told you in the other post, those mouse IR LEDs and IR fototranzistors you can use for line following or wheel encoders. Read the tutorials and you will see.

The sensors from the link that I gave you are Sharp IR Distance sensors that you can't replicate with mouse parts.

The pin header you need to connect the servos and sensors to the Arduino board. And yes, you need to solder wires to these pins. Or, you can get some Jumper Wires http://www.sparkfun.com/commerce/product_info.php?products_id=8431

You want to use salvaged parts but not to solder anything??? Those salvaged parts need to be unsoldered anyway... I guess you can use a breadboard... in this case you need the Arduino Proto Shield http://www.sparkfun.com/commerce/product_info.php?products_id=7914 and a small Breadboard that you glue (it's self adhesive) in the middle of the Proto Shield: http://www.sparkfun.com/commerce/product_info.php?products_id=7916

If you want to do it the easy way (no soldering involved) you need more money to buy a complete robot kit like the Parallax Boe-Bot or Lego Mindstorms NXT.

this is the board http://www.sparkfun.com/commerce/product_info.php?products_id=666&action=add_product# i was hoping that i only have to plug the servos there and the sensors and programme it... isnt that so?

[Ro-Bot-X]

Servos have 3 pins (on a female connector), Signal, Power and Ground. Same goes for IR Distance sensors (actually, these have a small 3 pin male header, so you need to buy pre-crimped wire connectors, or solder wires directly)
Arduino board has female connectors for Signal on one side and for Power and Ground (GND) on another side. So you need the Jumper wires to make the connections or to cut the servo cable near the connector and split the wires separately for Signal and Power + GND and solde pin headers on them.

Do you understand this?

[robonoob]

Servos have 3 pins (on a female connector), Signal, Power and Ground. Same goes for IR Distance sensors (actually, these have a small 3 pin male header, so you need to buy pre-crimped wire connectors, or solder wires directly)
Arduino board has female connectors for Signal on one side and for Power and Ground (GND) on another side. So you need the Jumper wires to make the connections or to cut the servo cable near the connector and split the wires separately for Signal and Power + GND and solde pin headers on them.

Do you understand this?

OK i understand the theory but in practics i wouldn't know anything though
thank you for this but would you plz make a schematics  for me so i could understand it better?
PS: i may want to make the robot with photoresistors maybe, you know like the $50 robot that goes towards the light... i think this might be easier for me to build because as i said this is my first robot
what do you think about that? would it be easier?

[robonoob]

okei then... nobody's willing to make me a schematics so i tried to make myself...its with two servos and a IR range finder... plz take a look on it and tell me if there's something wrong

[bukowski]

Why do you have the +5V going to a resistor and the IR Rangefiner output?

[ed1380]

the rangefinder is an IR led and receiver, so it needs +5v and ground and it send out a signal

[Rebelgium]

You connected the servo signal lines to the analog input connectors.
It should be connected to digital outputs of the Arduino.

[bukowski]

the rangefinder is an IR led and receiver, so it needs +5v and ground and it send out a signal

Yeah, but hes got the +5v going to the + lead and a dropped down voltage going to the output signal. Im thinking that that would give you erronous readings. But, hey maybe I dont know what Im talking about. Wouldnt be the first time!!

[paulstreats]

the ir range finder definately doesnt need a resistor between the +5v and signal wires.
The ones i have used have all come with connectors and there is no connection between +5v and signal.
Maybe you assume that it needs a pull up resistor. An analogue style range finder doesnt. Maybe the digital ones do? if you use the digital ones, then you should realise that they dont tell you correct ranging data, they merely tell you if an object is located below a pre defined range.

[robonoob]

Why do you have the +5V going to a resistor and the IR Rangefiner output?

well i don't know i just copied these pictures :http://wiring.org.co/learning/tutorials/diagrams.html
and tried to connect them like it is connected there
oh and the servos... i tries to fix it too look at it now and plz tell me if it's right now...

[Admin]

This is why I don't like the Arduino, it has no power bus thereby making wiring complicated . . . that and the 2V dropout . . .

Anyway, I don't think it is wise to connect the servos to the 5V regulator. The regulator could over heat thereby shutting down your Arduino, or at least cause brownouts.

You want to directly connect your servos to a 6V battery (with common grounds, of course).

[paulstreats]

that picture is definately for a digital range finder, so they must need a pull up resistor.
The one you have either doesnt need a pull up resistor because its an analog one. Or if it is a digital range finder then you need to move the signal wire to a digital i/o port one the arduino

[robonoob]

umm okei that confused me a little...
First: admin do u mean that i use 6V batterypack for two servos and only a signal wire goes from servo to arduino?
Second: what is a pull up resistor and what is a digital range finder and what is a analog one :Di mean whats the difference and whichone should i use if I'm making a wall avoiding bot?
and i made the Admin version picture too(at least i think that Admin meant that )
Third:can anybody please explain me what does these things mean like digital input and output, analog in and so on so on...
Fourth: http://www.sparkfun.com/commerce/product_info.php?products_id=242 this is the IR range finder I'm planing to use... it says there:"has an analog output that varies from 3.1V at 10cm to 0.4V at 80cm"(what ever it means) so... do i need to use the resistor or not?
Fifth: admin u said that there is no power bus... maybe this would help if I'd buy myself these 2 things?(although i don't know how to use these...:S) http://www.sparkfun.com/commerce/product_info.php?products_id=7914 and http://www.sparkfun.com/commerce/product_info.php?products_id=7916 ah and could anybody please explain me how to use these things and...

[Fredrik Andersson]

Almost there... ^^

You need to connect the boards ground with the servos ground (note - only ground not +V) else the signal wires to the servos doesn't make an enclosed circuit.

Also, remove the resistor on the IR rangefinder. That sensor is an complete package as it is. You just need to connect it to +5V, Ground and an analog input on the arduino.

[Rebelgium]

umm okei that confused me a little...
First: admin do u mean that i use 6V batterypack for two servos and only a signal wire goes from servo to arduino?
Second: what is a pull up resistor and what is a digital range finder and what is a analog one :Di mean whats the difference and whichone should i use if I'm making a wall avoiding bot?
and i made the Admin version picture too(at least i think that Admin meant that )
Third:can anybody please explain me what does these things mean like digital input and output, analog in and so on so on...
Fourth: http://www.sparkfun.com/commerce/product_info.php?products_id=242 this is the IR range finder I'm planing to use... it says there:"has an analog output that varies from 3.1V at 10cm to 0.4V at 80cm"(what ever it means) so... do i need to use the resistor or not?
Fifth: admin u said that there is no power bus... maybe this would help if I'd buy myself these 2 things?(although i don't know how to use these...:S) http://www.sparkfun.com/commerce/product_info.php?products_id=7914 and http://www.sparkfun.com/commerce/product_info.php?products_id=7916 ah and could anybody please explain me how to use these things and...

Pull up resistor, digital/analog rangefinder, digital/analog signals:
Search the forum and google.

power bus:
You can't buy a power bus, a power bus is a row of pins on your arduino PCB that's connected to +5V and another one to ground.
So you can connect external hardware easily.

[robonoob]

Almost there... ^^

You need to connect the boards ground with the servos ground (note - only ground not +V) else the signal wires to the servos doesn't make an enclosed circuit.

Also, remove the resistor on the IR rangefinder. That sensor is an complete package as it is. You just need to connect it to +5V, Ground and an analog input on the arduino.

hmm i don't get what u mean by that could you please download the picture and modify it for me please?

[Admin]

If you look at my $50 Robot, the pins where you connect the servos and sensors is a power bus.

You need to make something like that to plug everything in.

[robonoob]

If you look at my $50 Robot, the pins where you connect the servos and sensors is a power bus.

You need to make something like that to plug everything in.

i know what a power bus is but is still dont get the connecting thing... where do i have to connect the servos and the IR range finder

[Ro-Bot-X]

You should definitely read the tutorials on this site. Here, if you can't find them, this is the link:
http://www.societyofrobots.com/toparticles.shtml

[Mega]

Today I received my Arduino board. I plan to use this as the controller for my HummBot.
The Arduino will control two Sharp GP2D15 IR sensors, a DC motor and one servo.
I will follow the approach as described here:
http://itp.nyu.edu/physcomp/Labs/Servo
and here:
http://itp.nyu.edu/physcomp/Labs/DCMotorControl

Would this be a good approach?

Mega

[Ro-Bot-X]

Mega, verry good examples. You just need to combine them. Use the DC motor for propulsion (forward-backward) and the servo for steering. You may want to add another servo for scanning the Sharp sensors, because the car like steering is hard to maneuver out of corners, so you want to find bad spots before you get into them. And is also good for pathfinding.

Keep the input switch (maybe add some more), add a 2x8 or 2x16 LCD so you can input start and finish coordinates and see them on the screen, then have the car drive between obstacles like a real DARPA car. Take a look at Admin's wavefront algorithm to do it. You are on the right track.

Ohh, I almost forgot, you need encoders for pathfinding.

[Mega]

You may want to add another servo for scanning the Sharp sensors, because the car like steering is hard to maneuver out of corners, so you want to find bad spots before you get into them. And is also good for pathfinding.

Yes, I plan to do this. I would like to have a servo controled sharp inside the body of the HummBot. I'm slighly worried that the window frames of the body will interfere with the IR signals, so I'll have to position the servo/sensor carefully.

Next to that I will also need (sharp) sensors in the bumper of the HummBot to detect low objects.

Take a look at Admin's wavefront algorithm to do it. You are on the right track.

Excellent! I will definitely experiment with this algorithm.

Ohh, I almost forgot, you need encoders for pathfinding.

Yes, I have been thinking about this. But I have not figured out yet what would be the best way to add an encoder to by HummBot chassis:


There is no space near the wheels. One option might be to attach the encoder wheel to the drive shaft that attached the front wheels to the DC motor...

[robonoob]

mega i looked the links you gave...but unfortunately i didn't find anything for myself but thanks anyway...
so...I'm still waiting for somebody to help me with my schematics...
could anybody please download the picture and change it the way it needs to be? remember: this is my first robot and i don't know much about electronics
i also wanted to ask you why do i have to have nother battery pack? there is a plug where i can put an extra power on the arduino board... isn't that enough?

[Mega]

mega i looked the links you gave...but unfortunately i didn't find anything for myself Sad but thanks anyway...
so...I'm still waiting for somebody to help me with my schematics...

The servo connection looks ok, it is the same as in the link I sent: http://itp.nyu.edu/physcomp/Labs/Servo
Also, the IR sensor connection looks ok, except for the resistor, which is not needed as far as I can see.

[robonoob]

OK mega...
the link you sent... why is 1 of the Servo's connections opened? why isn't that connected to anywhere?