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Jul 22, 2016, 09:27 AM
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New Product

Chickadee Tech F3 and F4 Polystack Flight Controllers


Introducing Polystack! Its a flexible microcontrol system originally designed for flight control!

Hows it work? First you stack a power source on the bottom, place a control board on top of that and then stack up to seven mods on top to get all of the functionality you want.



The flight controllers run Betaflight 3.0 and autoconfigures as many settings as it can based on the mods that are stacked on top.

JoshuaBardwell has a first look at it here:
PolyStack Modular F3 and F4 Flight Controller System (9 min 13 sec)


The website is now live at https://chickadee.tech. This post will get updated with those later.

Available boards are:

Power:
Pololu Power cradle

Control:
F3 Flight Controller - STM32F3 + MPU-6000 over SPI

F4 Flight Controller - STM32F4 + MPU-6000 over SPI


Mods:

For RC Receivers:
X4R-SB Cradle
D4R-II Cradle
Receiver Breakout

Others:
MicroSD
MicroMinimOSD Cradle
Dual Serial Breakout

Development boards:
Debug board - breaks out all pins from Polystack connector.
Test Jig Bottom
Test Jig Top
Last edited by tannewt; Jul 27, 2016 at 07:38 PM. Reason: Website now live!
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Jul 23, 2016, 09:40 PM
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coreyltexas's Avatar
I can't wait to try this fc out!
Jul 24, 2016, 01:03 AM
Registered User
I'm glad you are! I can't wait to get it in more people's hands!

I'm hoping to launch next week sometime. Make sure you are on the mailing list. Thats where I'll announce first!
Jul 26, 2016, 11:48 PM
Registered User
I'm actually interested in developing a board. What software do you use to layout the pcb? Do you have files for the FC that I could play around with?
Jul 27, 2016, 12:04 PM
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antwerx's Avatar
Hi. This project looks really really interesting. I enjoyed Josh's video.

I only fly F4 boards. While I am happy with my Revolutions and a new KKNG F4 Fury I would love an opportunity to experience your board system.

I am currently active with RaceFlight firmware and have worked as a team builder for RaceFlight.

Please let me know if you will have any test boards available. I am seeking subject matter to review and make videos.

Steve.
Jul 27, 2016, 06:06 PM
Registered User
Boards are now on sale at https://chickadee.tech! Use "RCGROUPSLAUNCH" at checkout for 5% off.

Quote:
Originally Posted by Jahnkeanater
I'm actually interested in developing a board. What software do you use to layout the pcb? Do you have files for the FC that I could play around with?
Layout is done in Kicad. I've got many videos of me designing boards here: https://www.youtube.com/c/chickadeetech

All Polystack boards I've designed are open source. The files are here: https://github.com/chickadee-tech

Quote:
Originally Posted by antwerx
Hi. This project looks really really interesting. I enjoyed Josh's video.

I only fly F4 boards. While I am happy with my Revolutions and a new KKNG F4 Fury I would love an opportunity to experience your board system.

I am currently active with RaceFlight firmware and have worked as a team builder for RaceFlight.

Please let me know if you will have any test boards available. I am seeking subject matter to review and make videos.

Steve.
Steve, boards are generally available now! They don't run Raceflight, however, because the newest code isn't generally available. An old version of RC8 is available but I don't recommend it.
Jul 28, 2016, 02:52 AM
Registered User
Have you thought about utilizing the vcc plane to route some of the signals?
Also on the Revo there is a cutout on every single plane underneath the mpu-6000 to ensure it remains isolated from interference.
Jul 28, 2016, 02:57 AM
Registered User
Quote:
Originally Posted by Jahnkeanater
Have you thought about utilizing the vcc plane to route some of the signals?
Also on the Revo there is a cutout on every single plane underneath the mpu-6000 to ensure it remains isolated from interference.
I hadn't considered running signals on the internal VCC plane. What could that allow us to do?

I didn't know that cutting out the planes could be better than having planes underneath. I made sure no signal wires run under it though. Its been flying well in our tests.

Heres a video of Roth running the F3FC.

Do You Feel It!!! (2 min 49 sec)
Jul 28, 2016, 06:52 AM
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opiswahn's Avatar
Nice idea, but way to expensive. $100 for a half decent stack... Thank you but no thank you
Jul 28, 2016, 11:21 AM
Rgietsered Uesr
velez's Avatar
Arenīt those metal nuts in the top of the stack directly on top of some traces? The only thing preventing a short seems to be the solder mask.

I guess you could add a nylon washer prior to the metal nuts in your .GIF.
Jul 28, 2016, 01:32 PM
Registered User
Quote:
Originally Posted by opiswahn
Nice idea, but way to expensive. $100 for a half decent stack... Thank you but no thank you
What do you mean half decent? I understand its pricier than most single board FCs but it also does a lot that they don't.

Quote:
Originally Posted by velez
Arenīt those metal nuts in the top of the stack directly on top of some traces? The only thing preventing a short seems to be the solder mask.

I guess you could add a nylon washer prior to the metal nuts in your .GIF.
Oh yeah! I'd never noticed that and haven't had a problem. The benefits of clear solder mask! I kept parts away from the bolt area but not traces. I'll have to look into nylon washers. Thanks!
Aug 01, 2016, 01:52 AM
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opiswahn's Avatar
Quote:
Originally Posted by tannewt
What do you mean half decent? I understand its pricier than most single board FCs but it also does a lot that they don't.
And that would be what? You got Docks for your RX, OSD, SD-Card other stuff, well, that you'll get in every decent PDB or even in the FC itself for a fraction of that cost. And really, who needs a dock for a RX...

Again, the idea is quiet nice, and if you have enough space in the frame it would be ok, but i doubt a 3 or 4 stack module will fit in any 200er sized quad. The standard 250 might fit, but that's it.

So its way to expensive, has a lot of room requirement any due to the many components a very high Point-Of-Failure-Value.
In my eyes, that makes it a very fragile, expensive experiment. From an engeneering PointOfView it is really cool, but... well... in the real world i think it stands no chance.
Aug 01, 2016, 02:23 AM
Registered User
Quote:
Originally Posted by opiswahn
And that would be what? You got Docks for your RX, OSD, SD-Card other stuff, well, that you'll get in every decent PDB or even in the FC itself for a fraction of that cost. And really, who needs a dock for a RX...

Again, the idea is quiet nice, and if you have enough space in the frame it would be ok, but i doubt a 3 or 4 stack module will fit in any 200er sized quad. The standard 250 might fit, but that's it.

So its way to expensive, has a lot of room requirement any due to the many components a very high Point-Of-Failure-Value.
In my eyes, that makes it a very fragile, expensive experiment. From an engeneering PointOfView it is really cool, but... well... in the real world i think it stands no chance.
Yeah, I get that most of the current functionality is comparable to whats already available. I'm hoping to create a more diverse set of mods in the future that will stretch things further and distinguish Polystack from current options. Native OSD and VTX are things I want to start prototyping. I want to do a mod for autonomous flight too. One person on an iNav thread mentioned ultra wide band radios as a way of doing really precise positioning which could have cool applications.

Its early days for Polystack and I hope to find some early adopters who want to experiment with it. :-) All of its IO has lots of potential.

Do 200er frames run standoffs shorter than 250s? 30mm seems pretty common to me. I can get three core boards power, FC and receiver plus two mods (microSD and OSD) into one of my 250s just fine even though the FC has pin headers for the ESC outputs. Theres a bit of room to optimize there too. We could also create a board to send signals back downwards and double the "height" of the stack. We'd need a way to add mounting bolts for that though.
Aug 03, 2016, 08:37 PM
Registered User
Quote:
Originally Posted by tannewt
Do 200er frames run standoffs shorter than 250s? 30mm seems pretty common to me.
I'm kind of with opiswahn.
Nice idea, but too big and potentially fragile.

Most 200er frames have 30.5mm mounting holes, but are limited in their vertical plane to <20mm.

Personally I like the design of Kombini, except for the Spek. Sat. connector, I like solder holes/pads. If they included a removable mSD card dongle it would almost be perfect... so the board just had a 6pin connector for the SD, which could be easily removed.
Last edited by raybies; Aug 03, 2016 at 08:45 PM.
Aug 03, 2016, 11:49 PM
Registered User
raybies, do you have links to some example frames? It'd be interesting to see how much we could fit into a small space.