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!

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

  1. Peter "Pedro" Newman

    I just completed my first tinyFISH FC build and this is by far the most challenging FC build that I have undertaken so far. Thanks to Simon again for the chance to do this.
    PS – I decided not to fit the chip for Blackbox at this stage but maybe in the future
    Some images of the completed board
    https://imgur.com/a/CJntv
    https://imgur.com/a/70vEm

    Reply
    1. fishpepper Post author

      Congratulations for your successfull build! That looks quite good! Where did you get the PCBs made? Thanks for sharing teh pictures.

      Reply
      1. Peter (Pedro) Newman

        I got the PCB’s from your OSH Park link Simon. Looking forward to getting it into a build once I decide on one ๐Ÿ™‚

        Reply
        1. fishpepper Post author

          I was wondering because they look black on your pictures. Is it just the light or did OSHPark start selling non purple pcbs?

          Reply
          1. Peter (Pedro) Newman

            They are still purple but under the pretty crappy USN microscope they do look black ๐Ÿ™‚

            Just to let you know the notification system for replies here does not work either. I have both boxes ticked and never get notifications.

          2. fishpepper Post author

            Ah ok. It looked so dark that I never thought about this could be purple *g*

            Thanks for letting me know about the notifications. I applied some fixes and it should hopefully work now ๐Ÿ™‚

  2. Steven Merrell

    What is the purpose of v out +? I have purchased two different stacks a luminier and a boldclash. The luminier had the battery input pigtail connect directly to the esc and wires from the esc to the in – and in +.

    The boldclash has the battery input pigtail connected to the fc in – and in +. Then out – and out + is going to the rec.

    Which way is the correct way?

    Lastly using the new 1/2s esc what is the correct way of wiring that one to the flight controller?

    Reply
    1. fishpepper Post author

      You should connect the battery to the in pads. Then add some wire and connect all peripheral parts like the ESC or the cam to the out pads. This way you will have current meter readings in telemetry ๐Ÿ™‚

      Reply
  3. Jakob

    Think I have problem with radiopart on my TinyFish build. Looking for suggestion on how to find out exactly what is wrong. Using the 0.1 rev of pcb and have tried all different fw rev. for now I’m testing the latest. When powering on, with or without bind jumper set I’ve got solid green light. Have usky since before so have confirmed bind procedure and also have compared 26Mhz between the two of them, not super accurate since I using an old 20Mhz scope. Have tried to monitor debug data. From what I’ve can see it’s no signal on that pin. Also tried the boot mode (data pin ) and got flashing red and green – guess thats a sign that fw is running ok since detecting boot pin shorted.

    Reply
    1. fishpepper Post author

      Do a visual inspection if all pins of the stm32 and the CC2510 chip are soldered properly (no visible gaps, no solder blob shorts, etc).
      Or maybe the bootloader fw is ok and the main fw is bricked? You could try to update the rx firmware by following these steps.

      Reply
  4. Louis

    For the U5 flash memory in the bom, the package is showing VFDFPN8
    the farnell id is also link to M25P16-VMP6G having the VFDFPN package
    However the value is M25P16-VME which i believe the package is VDFPN
    Im confused, which one is the correct one?

    and this component seems No Longer Manufactured as shown in farnell, any alternative recommendations?

    Thanks!

    Reply
    1. fishpepper Post author

      Racerstar and others managed to mount the normal soic8 version onto the pads. Seems like the pads are good for both types ๐Ÿ™‚
      I selected the other type mainly because it was less high.

      Reply
  5. Joerg Eesmann

    HI,
    I am building 2 board right now and have to admit, I hate 0402…
    how long is the antenna? Is there a possibility to optimize SWR using RFStudio?
    Great project by the way, thanks for ur effort.
    BR
    Joerg

    Reply
  6. baschtler

    hej there o/

    since i’m a 100% hobbyist i’ve no clue how to read that google-list. probably someone could tell me if the “B” section ist the quantity of the parts needed to build up the fc and what “E” section stands for?
    another big thing i don’t get is where to find the circuit diagram to know where to solder the parts.

    the idea to build a fc with my own two hands (still waiting for 2 brushed replacements from china) to repair friends micros is fantastic. i’ve very steady hands, a lot of patience and time.
    made a mouser account to get all parts in line and am planing to get the boards from your linked (community driven) vendor.

    i’m in the hobby since 5 month and repaired a lot of stuff. had to solder (repair) a lot on these tiny boards and never had a problem so i thought to give it a try.

    thanks a lot for your invention and the move to made it free knowledge <3

    o/

    Reply
  7. Jayson Wallis

    Just completed 3 flight controllers and 3 speed controllers. Thanks for releasing such a wonderful project. This was my first time doing any SMD work so while a challenge it was very rewarding. I will be installing these into 2 self made frames in the next few days and keeping one set as a spare. I cant wait to get these flying and waiting for your next add on project…

    Thanks again for your efforts.

    Jayson

    Reply
  8. Steven Flemington

    Hi Simon, I’m about to have a go at building and can’t find any source for the crystal. I’ve tried Farnell, Digikey and Mouser where I get most of what I need usually but they are all out of stock. Is there an alternative or do you know anyone with stock?

    Cheers Steve.

    Reply
    1. fishpepper Post author

      I got mine on aliexpress, see the links on usky page

      Reply
      1. Steven Flemington

        I managed to find some in stock at Arrow.com thanks. A few items are challenging to track down but I have all I need on it’s way, next challenge is the build.

        Reply
  9. winslow49

    Excellent design!
    But could you remove the M25P16-VME๏ผŸThe PIKO BLX flight controller had remove this component,This can make the controller more chipper and more smaller.

    Reply
  10. mhvdrone

    Hi, I’m having some trouble with the RX – I’ve flashed the CC2500 firmware and it seems to be operating – I get a solid green LED, and if I power up with bind pressed it’s rapid flashing instead. However, can’t seem to bind and I never get any activity on the receiver panel in betaflight. I’ve tried to hook up to the debug port, but I don’t see any data there. Any suggestions?

    Reply
  11. 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
  12. 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
  13. 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
  14. 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
  15. 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
          1. Peter "Pedro" Newman

            Thanks for the reply Simon. Just completing a Digikey cart and looking forward to the build ๐Ÿ™‚

          2. Andrew Dalton

            Is there a way I could make spektrum work on a premade board. I would really like to build one and preferably be able to buy the complete stack off of get fpv. Can I just like cut a couple traces or something to make the integrated rx not work and then add an external rx.

          3. fishpepper Post author

            No cutting is required, just add a spektrum RX to the pads labeled RX3 and TX3 (uart3) and reconfigure betaflight to use a spektrum rx on uart3 ๐Ÿ™‚
            A friend of mine is actually flying that kind of setup. If you go 1S make sure to get a rx that works on 1S, some have spurious resets on low battery…

          4. Simon

            I cannot configure iBus on UART 3. It always defaults to “Disabled” after save and reboot.
            Is it a valid combination with Tinyfish FC? I am using FS-A8S RX to RX3 connector and 2S power.

          5. fishpepper Post author

            Did you disable serialRX on uart1? I am not sure if bf allows you to configure two serials as serialrx.

  16. 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
  17. 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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