Picopter

It's a tiny quadrotor helicopter!


Update May 4 2012: I am still working very hard on version 3 of Picopter. The new version's hardware is already done. There are new 3D printed motor holders. I've done some measurements with regards to mass and radio spectrum. I've posted stuff to http://www.frank-zhao.com/picopter_forum/index.php including the new design files, so take a look.


Update Feb 24 2012: I did not expect this much response. I've given away all of my blank PCBs, sorry, I'm working hard to fulfil people's requests and investigating the possibility of a kit. I have setup a forum so you can sign up, keep up to date on my progress, and allow me to notify you of big news easily, visit it here http://www.frank-zhao.com/picopter_forum/index.php

Update Feb 25 2012: Warning, I may have discovered a bug inside the CadSoft EAGLE 6.1.0 software that may make the PCB look slightly different. My design files are meant for 5.11 so use that instead. You have been warned.

Main Features:

• X mode flying
• MPU-6000 gyro & accelerometer sensor for flight stabilization
• USB battery recharging on the transmitter, the copter plugs into the transmitter to recharge
• When the copter plugs into the transmitter, the user can synchronize to a random radio frequency
• Controlled using a Wii Classic Controller, which plugs into the transmitter
• Running a modified MultiWii firmware, which is open source, written with Arduino and Processing

Dimension Specs:

• Square center body is 1.5" by 1.5"
• Propellers are about 45mm in diameter
• Diagonal motor to motor distance is 110mm
• Motors are supposedly "X-Twin" spare motors, they come with the propellers

Electrical Specs:

• Flight battery is a single Li-poly cell, 3.7V, 350mAH, 20C
• Controller battery is a single Li-ion cell, 3.7V, 1000mAH
• Uses ATmega128RFA1 microcontroller for both copter and transmitter
• This particular ATmega has a built-in 2.4GHz transceiver, 16 possible channels, 250kbit/s or 2mbit/s max depending on the standard being used.

Design Highlights:

• The "arms" and "body" are connected by locking slots, making them easy to build and repair
• Motors slide right into the arm
• Two layer 1.6mm thick FR4 PCB used (this is the default for a lot of PCB manufactures), the components are all on a single side (easy to assemble)
• All open source project, schematics + PCB + code all available. Heavy use of Arduino and Zigduino involved.

This is actually the 2nd such tiny quadrotor helicopter I've built. The first one worked well and I'm extremely proud of it, but it did have several flaws, enough flaws to justify a remake. This Instructable documents "version 2", but you may see pictures of "version 1" in some places.

Step 0 Come up with puntastic name
Pico... Copter... You get the idea. This project was originally named "PalmQuad" since it's small enough to fit in your palm, so if you might see some mention of this name in the code or pictures.

I originally finished building "version 1" in November, and wrote the Instructable in November. Then I went on vacation for a few weeks, and also school just started. Now it is February and I just finished "version 2", but since I've already written the majority of the Instructable, I have some bits of "version 1" text that I'll just cross out like this, and then update it with the changes in "version 2".

All project files are available to download in this instructable "step". It contains files for "version 1" only for reference purposes, please only use "version 2" files. Although I really recommend you only take my concepts and design everything from scratch yourself instead, just so there's absolutely no mysteries in your project.

If you are wondering about the lack of a flight video, see step 6 for an explanation.

Oh and I noticed that "AdBlock" stops Instructables from showing you all my pictures, so please turn it off.

Step 1 Version 1's Build Log

This instructable will focus on building version 2 due to the flaws in version 1, but I have a lot of pictures taken during the construction of version 1, I'm putting them all in this step. I think it's a good idea to show people my other techniques so everybody can learn from both the benefits and mistakes.

Version 1 is soldered using the reflow soldering method (see my other instructable: http://www.instructables.com/id/Hack-a-Toaster-Oven-for-Reflow-Soldering/), version 2 was not due to time constraints and l didn't bring my oven to school. I managed to solder the QFN chips with a heatgun.

In version 1, the flyback diode for each motor was mounted onto the arms, but in version 2, the flyback diodes are in the main quadcopter body PCB instead.

In version 1, the propellers required a drilling before they fit onto the motor. The motors in version 2 comes with the propellers pre-attached so the drilling is no longer necessary. However, please read step 6 to see why you should use the motors from version 1 instead.

Comments

[sachin456]

hi,sir i need quadcopter's blank circut's print can iget it sir

[sachin456]

please sir please sir help me

[sachin456]

sir can you write the list of parts used in the circut board

[sachin456]

sir can you write the list of parts used in the circut board

[ckarcz]

if you can't find this stuff on here, what makes you think you can build this thing?

[supercapacitor]

A complete product and a true feat of engineering. This is excellent!

[gu2n_ok]

hai frank you make all this by your self .... wow it's cool i want the make this where i can get the component???

[frank26080115]

You can get the components by searching DigiKey for the part numbers I provided, they have almost everything. Some of the stuff you can't find, you'll need to visit SeeedStudio, SparkFun, and Google.

[gu2n_ok]

For the mainboard ?? Were I get that?

[frank26080115]

You have to send the design to a PCB manufacture to have it made for you

[TripleQ]

you make this circuit board all By yourself?you are amazing,my dream is make a flying tiny robot but too bad i not pro in electrical : (

[WesleySwain]

Are you planning on producing these boards to sell? If so, I will gladly buy one!

[frank26080115]

I would like to try, maybe attempt a "Kickstarter project" or something.

[since76]

You NEED to put this on Kickstarter! :)

[Kryptonite]

I would back this, and then buy it for sure.

If possible, selling two versions of this, one being a 'assembly kit' while the other a 'ready to use', would be a brilliant idea!

[nagutron]

Kickstarter could be a great way to do this. You'll need a solid business plan and some flashy videos of your prototype flying well, but I think you'd get a lot of interest now that quadcopters are all the rage.

[Retro Correct]

I agree, this could really take off on a service like kickstarter. it's small, open source, uses standard inputs from the wiimote, well designed, and developed privately to be a legitimate tool/aircraft. The geek media is clamoring for stuff like this, especially since the release of the quad copter videos at Upenn.

-yes there is a pun

[ericj]

Hey Frank-

Quick question about using the USBTinyISP to flash the AVR chip. The Adafruit docs say that the USBTinyISP can't flash larger than 64K sized chips, and the ATMega128rfa1 looks like it's 128K.

You didn't experience any problems though it sounds like? Just wanted to doublecheck as I'm about to pick up the ISP programmer from Adafruit.

Thx! Awesome project!
Eric

[frank26080115]

Oh... err, funny thing, it "works", you can write to the chip, I know I can because I wrote the bootloader to it, the bootloader resides in the absolute last section of the memory. So it can definitely write all 128KB

But the problem is reading the 128KB, it won't work, which means you cannot really perform the verification step, and AVRDUDE will think that it failed since the verification fails. In reality, it might have failed, it might have worked, you have no way of knowing unless you do a lot of testing. In the end, I just check if my bootloader is working, and then use the bootloader from that point onwards.

[ericj]

Awesome, I figured as much. Just wanted to double check...

Thanks!

[ms10]

nice splendid picocopter

[de-tech]

Hey frank great picopter, I can't till I have the money to make one. I have a DX6i spektrum. Is it possible to make the copter work with it? If so, how do you do it?

[frank26080115]

There might be a way but I don't recommend it. You should really do a complete redesign if you want to try. But if you really want to hear how I would "hack" my own circuit to do this right now... then...

You need to get a special Spektrum receiver that outputs a single PPM signal that combines all the channels.

If you get one small enough, you can probably mount it onto the quadcopter itself and wire it to one of the SPI pins available on the docking connector. Or else you wire it to the docking connector of the transmitter circuit. I would probably create a entire "Spektrum Addon Module" that docks with the transmitter circuit.

The software needs to be modified to read the combined PPM signal. I've done this many times before. It's a piece of code that continuously measures pulse widths using a timer and pin change interrupts.

So if you have a tiny receiver, the quadcopter can take commands from the Spektrum directly, but if you don't have a tiny receiver, then my transmitter circuit can act as a relay for the commands.

Both methods will be highly experimental and require a lot of testing

[frank26080115]

check these out http://deltang.co.uk/

[de-tech]

Yeah, I going to need to redesign the picopter to make it work with the spektrum. I'm thinking of using a Rx31 receiver and an atmega128A. I'm going to need to look into the receiver some more though to see which best suit the copter, and do you think the atmega128A going to work for this project. I don't need the 128RFA1 sense I would not be using the RF. Plus it has more I/O port and I could use it for each of the receiver channel. Or do I still need to find one that use single output for the receiver.

[frank26080115]

you are going in the right direction

Almost any ATmega should work, do a comparison with the ATmega328P, if it has the same or more timers, and the same or more memory, then it should work.

[de-tech]

Thanks for the help. This is perfect I have arduino uno that have atmega 328p chip. I can do all my testing on it before buying the parts. However, can you help me on that PPM signal coding, when every you have time. Or give me some hint on were I can get some information on this stuff. Thank again.

[de-tech]

Check this out. http://rcexplorer.se/projects/TriV2/TriV2.html

This going to help me out a lot.

[ciroman]

Wow man, this is awesome! I can only imagine the hours spent on this project...
I wish there were more people like you around. Really great project.

Shame it didn't make it to the finals

[frank26080115]

Hours? Something like this takes several months.

this entire project started in the spring of 2011, I had a really old layout done, but I had no good way of doing SMD soldering back then. So I actually paused the project to develop my reflow soldering oven (also two USB related instructables). That had to be done, then I was able to solder the first prototype of Picopter in October 2011.

I had to spend time on the Zigduino first to see if the ATmega128RFA1 was suitable, that was another two weeks dedicated to writing, testing, and performance optimizing code. It ended up becoming an Arduino library I put up on Google Code.

And PCB prototyping takes 1 week to design, 1 week to tweak, 1 week to manufacture, and 2 weeks to ship. Having a stencil made takes 1 or 2 weeks.

Oh and InvenSens decided it was cool to market their new super awesome combo sensor chip that everybody is drooling to use without giving a register map. They eventually released the document but waiting for that document was painful.

Can't wait to do this stuff as a job though, one more year.

I don't know why I typed all that, I'm in a study break right now.

[sourcand45]

this is an amazing project!
how much did i cost to make though?

[frank26080115]

over $200 if you count absolutely everything

[frank26080115]

:-(

didn't make the finalists for toy challenge 2

[tanatos]

Do you think it’s possible to hook up bigger motors/battery to this PCB? I mean – to make a bigger quadcopter out of this. Given the size/weight seems like an ideal design for all types of flyers – am I correct?

[frank26080115]

the motor driving circuitry is designed for small brushed DC motors, a bigger MOSFET may be needed for a larger brushed DC motor, if you want to use brushless motors, you will need one dedicated brushless controller for each motor.

the radio is not as long range or noise/interference immune as what is typically used for larger quadcopters (the latest radios have frequency hopping)

I don't think the circuit is suitable for a power source that's bigger than 3.7V due to the maximum ratings of the components, if you meant "bigger battery" in terms of capacity then maybe, but the 350mAH cell I used is the perfect size since it fits right underneath the PCB.

It is still possible to make a pico sized controller for regular sized quadcopters, but I'm just saying my circuit will need some changes before you can use it in that fashion.

[mustermann]

i u are planning to sell them, please make sure that they are avaidable in europe,too.

I like your work, bro!

[mondalaci]

My hat off to you! This is certainly one of the most impressive projects that I've ever seen (and I've seen *many*).

You could not only sell this a kit but as a fully fledged product. Time to be an entrepreneur. :)

[Qtechknow]

Amazing project. i would love to buy one from you. My SMD soldering skills are pretty nonexistent, but otherwise would love the opportunity to put one of these together.

[Hummer96]

Absolutely amazing build! I'd love to build one myself. Are there any boards available? Either blank or pre-assembled would work for me. Keep up the good work!

[frank26080115]

If anybody is interested in either building this project or buying this project as a DIY kit or fully assembled kit, it'll be great if you can tell me: what is your skill level (Can you program AVR microcontrollers? Can you code C and/or Java? Can you solder SMD discrete components? Can you solder QFN chips?), how it should be sold (blank PCBs with or without parts, semi assembled PCBs with or without parts, fully assembled PCBs, batteries, casing, motors, etc), and the price you are willing to pay.