tinyFISH FC – How to build your own! [revision 0.2b]

By | March 21, 2017

In this post I am going to share all the parts you need to build your own super lightweight tinyFISH flight controller with an integrated, FrSky compatible rx. All the following information applies to the current version 0.2b of tinyFISH (tagged as revision 0.2b).

Changes compared to the previous revision 0.2:

  • fixed the numbering of the esc pads
  • changed vreg to 3.1V

Circuit board

The PCB was designed to accommodate all the features I wanted in the smallest form factor possible. The outer dimensions are 20x20mm with a hole-to-hole distance of 16mm (M2). When manufactured in 0.8mm FR4 the completely assembled board weights silly 1.7 grams. This was only possibly by using small components, manual placement, and several tries on routing. The final result, tightly packed with 0402 sized components, require some good experience with soldering SMD components.

BOM

I updated the BOM a bit, you can now find a table with part references and ordering numbers for farnell and mouser on this google doc sheet. Please make sure to use high-Q high frequency parts for the hf section around the CC2510 chip as noted in the list. I ordered the majority of the parts from Farnell but you can probably get most of the parts at any electronic component vendor. Make sure to buy the MPU6000 from a reputable seller, I got some bad quality (fake?) chips from aliexpress…

Design files

The design files are released under the CERN open hardware license v1.2. Before using the design files for commercial projects please make sure that you read and understand this license! You can use the files for your projects, just make sure to give proper credit (by e.g. linking to the tinyFISH FC page). Additionally release all modifications you do and all work you derivate from this under the same license.

You can find the design in the kicad file format on my github repository. You will need a recent version from kicad. I compiled my own binaries from kicad commit efdfaeb.

If you want to skip the hassle of rendering the gerber board files on your own you can simply skip this step and checkout and order the part from OSHPark.com using this Link (rev 0.2b). They offer a really great quality for a ridiculous low price (it is 3$ for three copies!). Make sure to order the 0.8mm and 2 Oz copper version in order to save some weight.

Placement & Connections

You can use the following diagrams for the component placement. See my github repository for the full resolution files in SVG format.

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In addition to the part placement, those diagrams do also show you how to connect the various signals to this fc. The pads labeled CC_* are the ISP connection for the CC2510 and are used to flash the initial CC2510 bootloader.

Do it!

Now it is time to build your own! This page has all the information you need to build your own tinyFISH flight controller. Sure, this required very fine pitch soldering, but if you have some experience with SMD soldering give it a try! If this sounds to complicated to you, do not worry, I am quite sure someone will pick this design up and sell it sooner or later.

If you have built any my stuff I would be happy to see and hear how it turned out for you — send me an email!

17 thoughts on “tinyFISH FC – How to build your own! [revision 0.2b]

  1. Sam T-J

    I have successfully completed the flight controller! I had to rework the receiver portion a little, and after some trouble managed to flash it using a raspberry pi.
    Dataflash, current sensing and everything appears to be working!
    Sam

    Reply
  2. Jiri

    Hi, I very much like Your desing of FC & ESC and I appreciate very much the efforth You have put in.

    There is one tiny thing which I think would be beneficial in further revision – the FC & ESC board interconnect. Now it means that a bunch of cables has to be soldered on and squezzed between the two boards. Nice board to board pins(or pinhead) or aligned side connections (similar to motor pads) would simplify this and it would save some weight too.

    Reply
  3. 10.6um

    Was just about to order stuff from Farnell/Mouser. Unfortunately, neither has X1 (the 26MHz crystal) in stock.
    Are there any replacement parts you could recommend? E.g. any of this list: http://ch.farnell.com/webapp/wcs/stores/servlet/Search?rd=quarz&catalogId=15001&langId=41&storeId=10178&categoryId=700000005191&sort=P_PRICE&st=quarz&selectedCategoryId=%5BLjava.lang.String%3B%4041ad41ad&pageSize=100&beginIndex=1&showResults=true&pf=312004323,312004448,312004450,312004451,312004452,312005704

    Thanks a lot and have a great day!

    Reply
  4. Blaine

    Sorry to hear about the clones, parts and boards are on order and will be encouraging my club memebers to do the same and support open source!

    We appreciate and probably dont even understand the time and effort you have put in to this.

    Reply
  5. Felix Grubbe

    Hi, I am really interested in building this, because I also own a micro wich has too much weight for indoors and I don’t want thoose brushed copters. But I have a Spektrum transmitter. Is it possible to build somethin in this size with a Spektrum reciever?

    Thanks for reading! Have a nice day!

    Reply
    1. fishpepper Post author

      A friend of mine flies spektrum as well. We did not pupolate the tx part of the tinyFISH fc and he added an external small dsmx satellite.

      Reply
      1. Peter "Pedro" Newman

        Would it be possible for you or your friend to show us how the Spektrum sat was added to the tinyFISH FC and the firmware changed please Simon. Sort of defeats the purpose of the built in Usky RX but I would love to know how to do it please.

        Reply
        1. fishpepper Post author

          He simply wired it up to the spare RX port on the lower right corner (TX3/RX3). No firmware changes, just betaflight config to set up the spektrum sat. He powers the sat from the 3.3V stepup voltage on the vtx/cam combo (no dropouts).

          Reply
  6. Tim Kostka

    Maybe I missed it somewhere, but why the change to the 3.1V regulator? Was 3.0V causing issues somewhere? I’m making an FC very similar to this for a drop-in replacement for the Inductrix.

    Thanks for all the great work, especially the uSky which is just awesome that someone did that. ๐Ÿ™‚

    Reply
    1. fishpepper Post author

      The problem with the 3.0V reg was that my tinyPEPPER esc runs on lipo voltage. An efm8 with vcc=4.2 will not always detect 3.0V as logic high. 3.1V seems to do the trick for all efm8 boards I populated so far.

      Reply
      1. Lucas

        The 3.1V reg is just a drop-in replacement for the older revision board as well, right? Just received rev 0.2 from oshpark, wondering if just this replacement could work

        Reply
        1. fishpepper Post author

          It is a drop in replacement. No board changes were made for that ๐Ÿ˜‰

          Reply
    1. 24367dfa

      It’s a little sad, that the chinese clones are faster than i can procure all the parts ๐Ÿ™‚
      I’m going to build my own anyways and if it’s only for the challenge and newly acquired skills.

      Reply
      1. fishpepper Post author

        Go ahead and build it on your own. You will learn a lot ๐Ÿ˜‰

        Reply
  7. Sam

    Boards arrived today! Just gotta order some passives and I will be building a full FC and ESC Stack! I will let you know how it turns out!

    Reply

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