I am new to robotics and taking an introductory course on it. I’m trying to build a candy dispenser for my final. The idea is to have a humanoid looking figure sense a hand in front of it and lift its arm to present a skittle that falls out of its “pocket” (hip).
Anyway, I have purchased the Pololu Carrier with Sharp GP2Y0D810Z0F Digital Distance Sensor 10cm and a S3004 Standard Ball Bearing Futaba Servo. I don’t know how to hook the two up together, nor how to connect them both to a power source. I’d like to use batteries as the power source.
If anyone can help me figure this out I would greatly appreciate it. Thank you for your time.
Hello,
The Sharp Distance Sensor will generate a digital signal that is a 1 when something is in front of it and 0 otherwise. The servo requires a pulse-train input that can be generated by a microcontroller. Is there some robot controller that you are already using for your class? If not, I would recommend getting the Orangutan SV-328 and learning how to program it to coordinate the servo and the sensor. We include an example project that shows how to control servos, and reading a signal from the sensor is very straightforward.
We have a servo controller here at the school. It looks like a big RC controller, so I’m guessing thats not the same at all. Would the Baby Orangutan B-328 Robot Controller work with the Sharp sensor as well? I’m trying to keep things small inside the shell of the candy dispenser. it stands about 12 inches tall and is 3.345" thick and 5.147" wide at its widest point.
I think that both the Baby Orangutan and the SV-328 would easily fit within the dimensions of your candy dispenser, but I’m recommending the SV-328 because its LCD and easy connection points for wires make it easy to build and debug your project. Also, the regulated 5V supply of the SV-328 provides plenty of current to drive a single servo. What batteries were you thinking of using? Without knowing what your servo controller is, I can’t say anything about it, but it is probably not enough to do your whole project (unless it happens to have a sensor input!), and it is not needed at all if you get an Orangutan Controller.
If I get the Orangutan controller you suggested, I’ll probably use a 9V battery. Is that okay? Or will I run the risk of burning out the servo and sensor?
A 9V battery is typically not very good for applications that require a lot of current (we don’t recommend them as robot power sources), but it should work for you if your servo is small and not under heavy load. You will not be able to use the battery to directly power your servo or sensor (VIN must be between ~4.5 and 6V for a typical servo), but one feature of the Orangutan SV-328 is that it can deliver up to 3A via its regulated 5V bus, which means you can power your sensors and servo at 5V from your Orangutan while powering your Orangutan from the 9V battery.
What type of battery would be better suited than the 9V? I was thinking about getting one of the rechargeable ones from Pololu, but I’m not sure which one.
Any NiMH battery packs or or sets of individual batteries based on AA’s or AAA’s is going to be far better than a 9V battery in terms of current. You just need to make sure that the voltage is in an acceptable range for the SV-168, which requires 6-13.5V. Since a single AAA cell could start at 1.5V and drop to 1V as it discharges, you should use from 6 to 9 cells for reliable performance. I think the 3x2 AAA pack is a nice size. Do you have a charger for battery packs? You could also get a 6-AAA battery holder and put individual NiMH or Alkaline AAA batteries inside.
