Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: killsto on February 19, 2008, 07:12:11 PM
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I ordered my parts for my robot yesterday. I've done my share of research but still need help on a few things. I ordered:
- Arduino Diecimila
- Some wire
- 3 Hitec Hs-311 servos
- One Sharp IR rangefinder from sparkfun
- A small breadboard with only one set of power strips
Originally I was going to use a RC car for my chassis but the steering was not done via servo. What I plan to do now is use some kind of plastic and/or cardboard as my base and put an upside down big plastic bowl in it for protection and to stay together, kind of like the water bottle on the $50 robot. My problem is I don't know how to mount the breadboard and the Arduino. In theory I could use the arduino without a breadboard, but as far as I can tell there is only 1 power and one ground on it making connections kind of limited.
I'm going mount the Sharp IR on one servo to get readings from different angles. I'm going to modify the other two to power the wheels. Sounds good, right? Here's one of my main concerns, do I need any resistors or diodes for the servos and Sharp IR? For power I will use one 9V battery for the Arduino board and another for the servos and Sharp IR because a 9V battery is very easy to get and handle. Are there any resistors or something of the like I need for this? As far as I can tell, the Arduino board takes care of itself in terms of power regulation.
Thanks for any help and I am honored to be in the robo community.
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My problem is I don't know how to mount the breadboard and the Arduino. In theory I could use the arduino without a breadboard
You mean mount the breadboard and arduino on the chassis?
Also the arduino is always used with a breadboard , or some other circuit board , when dealing with motor control .
(http://gestaltung.fh-wuerzburg.de/blogs/exint_ws06/wp-content/uploads/2007/01/l293d_arduino.jpg)
Here's one of my main concerns, do I need any resistors or diodes for the servos and Sharp IR? For power I will use one 9V battery for the Arduino board and another for the servos and Sharp IR because a 9V battery is very easy to get and handle. Are there any resistors or something of the like I need for this? As far as I can tell, the Arduino board takes care of itself in terms of power regulation.
The arduino has a 5V power regulator built in . The servos and IR should run at 6V, and the power to the servos should NOT be regulated
Welcome to the community
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My problem is I don't know how to mount the breadboard and the Arduino. In theory I could use the arduino without a breadboard
You mean mount the breadboard and arduino on the chassis?
Also the arduino is always used with a breadboard , or some other circuit board , when dealing with motor control .
(http://gestaltung.fh-wuerzburg.de/blogs/exint_ws06/wp-content/uploads/2007/01/l293d_arduino.jpg)
Here's one of my main concerns, do I need any resistors or diodes for the servos and Sharp IR? For power I will use one 9V battery for the Arduino board and another for the servos and Sharp IR because a 9V battery is very easy to get and handle. Are there any resistors or something of the like I need for this? As far as I can tell, the Arduino board takes care of itself in terms of power regulation.
The arduino has a 5V power regulator built in . The servos and IR should run at 6V, and the power to the servos should NOT be regulated
Welcome to the community
Yup, I want to mount the breadboard on the chassis.
Why is there another chip in the middle of the breadboard in the picture?
Would the servos operate at 9V?
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the back of the 400 pin breadboard is a sticker. So you peel off the paper on the sticker on back, and then just stick the breadboard to whatever you want. Or you can use velcro to stick the breadboard to the chassis.
The chip on the breadboard i posted is a chip called an H bridge whose job it is to control the DC motor thats next to the batteries in the pic.
Servos have these chips built in, so no external chips are needed for control of servos
Servos are intended to work from 4.8V to 6V ,though they will run at 7.2V . If you have 9V and want to bring it down to 6V ( the best voltage for servos) then all you have to do is get a switching regulator or get diodes with a 1 volt drop across it , and connect 3 diodes to the battery to bring it down from 9 to 6 volts .
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the back of the 400 pin breadboard is a sticker. So you peel off the paper on the sticker on back, and then just stick the breadboard to whatever you want. Or you can use velcro to stick the breadboard to the chassis.
The chip on the breadboard i posted is a chip called an H bridge whose job it is to control the DC motor thats next to the batteries in the pic.
Servos have these chips built in, so no external chips are needed for control of servos
Servos are intended to work from 4.8V to 6V ,though they will run at 7.2V . If you have 9V and want to bring it down to 6V ( the best voltage for servos) then all you have to do is get a switching regulator or get diodes with a 1 volt drop across it , and connect 3 diodes to the battery to bring it down from 9 to 6 volts .
Alright, thanks for the help. I will get a battery case from radioshack and place 4 AA batteries (1.5V * 4 = 6V) in it for the 3 servos... and the IR range finder. The 9V should work for the Arduino, correct?
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right, 9 v with arduino is good
its a good idea to ground everything . Negative from 6V connected to negative from 9V, makes it simpler and better.