Step 10: LM317 Voltage Regulator

In order to be able to provide enough power for our servos, we need to have a separate power supply since the Arduino cannot supply the servos with enough current. The voltage range for these servos is around 5V. Since most batteries are not 5V we need to use a voltage regulator.

The LM317 is an adjustable voltage regulator that you can change to fit your power supply. You can find the datasheet for the LM317 here. We will be using the same circuit as on page 9.

The important part for the LM317 voltage regulator is to adjust the 5k trimpot so that the output voltage is at 5V. The LED can be used as a visual indicator for the voltage. If the LED is extremely bright or burning up, then you may have too much output voltage and your servos may be at risk.

Depending on how much higher your supply voltage is compared to 5V, there may be a considerable amount of heat generated. In this RoboBrrd, I am using 11.1V, which means the LM317 heats up quickly. I use a medium sized heatsink to help dissipate the heat.

On the proto-screwshield we want to design for maximum fixability. Therefore, we use female headers for the LM317 to plug into in case of the unlikely event that the LM317 stops working and we need to replace it.
We really appreciate your efforts on this project . I assure you that we will give it our best to become one of your first prototyes. When our Robotbrrd is complete we will post up what we have. As an instructor and teacher at Eaglesnest Robotics Learning Academy, I am proud that this activity will be entered into our curriculum and used to teach many of our students how to program and construct a robot. Thank you for your efforts. Our Vote is in.<br><br><br>Sean Lewis<br>Eaglesnest Robotics<br>www.eaglesnestrobotics.com<br>&quot;Exploring Young minds through Science and Technology.&quot;
Thanks so much Sean! It's always a pleasure seeing NEON NOODLE's robots on the Robot Party. :)
<p>BRAVOOOO... Very Well...</p>
<p>Impressive :-)</p>
Our best end goal should be competent to produce RoboBrrds along with band together through educational facilities to make RoboBrrds towards scholars because Build it yourself solutions them to put together, and utilize as the program. It is extremely helpful, as the scholars have a exceptional hitting the ground with their very own RoboBrrd considering that /they/ build it and therefore are capable of make it better. These are understading about several subject areas aided by the their production. It is just a marvelous expertise <a href="http://rate-my-professors.com/" rel="nofollow">http://www.rate-my-professors.com/</a> .
Hi ! I really love your project. I'm trying to make a Robobrrd but it's not easy to find the different parts in France. Could you give me more details about them ( references for the electronics and circuits). Thanks a lot!! And once again : BRAVO !
Whoa. My kids would love making this. Thanks!
Awesome project. I am a teacher at an elementary school and this has given me some great ideas for lesson plans.
There's a problem with two of the images for the bottom face. The thumbnails are present, but when you click on them, they are &quot;not found&quot;. The missing images contain the dimensions for the bottom face.
Heya!<br><br>Just uploaded all of the design files to GitHub. There are pdf versions available too, so you can download the entire repository as a zip and get all of the dimensions. :D<br><br>https://github.com/RobotGrrl/RoboBrrd-Design-Files<br><br>Hope that helps!
Yes, this is a known issue. Since this was an entrant into the laser cutter contest, the rules don't allow us to edit the Instructable. :/ We'll update it as soon as we can!<br><br>The weird part is that the image itself was uploaded fine, and worked fine for a few hours afterwards. Something strange must have happened on their server.<br><br>There will be more CAD images uploaded soon as well, I'll reply back with more details :)<br><br>Thanks for the comment!
Beautifully done. Inspiring young mind will benefit much. You're motivating them into a better future. ○☺○
Thanks so much Evelyn and alfiefalf!
I'm Doing my best to draw some good attention to the instructables site, I think maybe giving my family and friends the link to your page for RoboBrrd might help just a bit...<br><br>N2TOH<br><br>Pst, ... Laser cutters are cool, pass it on....
Thanks N2! Every bit helped, I'm sure. :)
What a wonderful project- thank you so much for sharing! I've been working on a robot project with my three boys and this has given me some great ideas. :)
Thanks Honus! Congrats on being a finalist in the laser cutter contest.
Your instructable is very detailed, but I think this step is not easy for beginners to follow. The schematic with the 2 protection diodes is on page 10 in the datasheet, not page 9 and it is difficult for beginners to see how the parts are connected, if they are not used to read datasheets, e.g. the right polarity of electrolytic capacitors and the connection of the LM317. It is not the circuit you are using, but I think this a good example how it could look like: http://laserpointerforums.com/attachments/f42/31562d1298103794-diy-homemade-laser-diode-driver-31410d1297294173-logical-way-setup-2x-lm317-driver-lm317.jpg
Off by one error on the page number, apologies!<br><br>There were additional pictures of a breadboard as well that help with the wiring.<br><br>I'll revisit this step and post some step-by-step soldering pictures for this on some perfboard, this should help! Plus, perhaps a drawing of it in Fritzing or the like.<br><br>Thanks for your feedback!
RoboBrrd &lt;3
So cute and it hula hoops!<br><br>This is a very thorough instructables and a very interesting project to introduce younger children to robotics and programming. I love the concept and the idea that you used simple everyday materials for the construction was ingenious!<br><br>I hope you get the funding you need to create your kits, I know I will certainly buy two. One for me and one for my sister who is applying for teaching jobs in elementary and high school for technology! She loves these types of things to show the students. She tutors a young girl now and showed her how to make a vibrobot using a toothbrush. <br><br>Good Luck! Wonderful instructable!
Put us down for at least 5 to start with.
Thanks sailormoon (your username brings back memories hahaha)!<br><br>Hopefully that young student will keep interested in robotics and make cool robots too. :)<br>
Such great creativity and accessibility, awesome!<br />
Thanks a bunch mikeasaurus! I love your halloween cheese burgers! Hahaha so cool. :)
This is incredibly thorough documentation.
Thanks James! Lookin' forward to seeing your 3d printer on the Robot Party this week! :)

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Bio: Maker of RoboBrrd!
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