Cube FPV

Tinyhawk 2 Freestyle LongRange

For this build, we look at giving a Tinyhawk 2 Freestyle flight controller a second life in a 3 inch long range frame. The purpose here is to give a practical example of how older hardware can be utilised in new builds, instead of investing in purchasing new equipment, which is currently quite expensive. The Tinyhawk 2 flight controller although being quite old is actually a good flight controller when set up correctly. 

Build Summary
1. Adapting the FC to fit a conventional frame
2. Setting up soft serial to free up a UART
3. Configuring 32 bit ESC software after upgrading

Note: This guide assumes that you have already replaced the standard VTX on the Tinyhawk FC as well as set up an external receiver – which most people usually do soon after purchasing.

Project Overview Video (YouTube)

This video goes through the whole process of fitting out the frame, and there is a sample flight at the end of the video. Importantly the video shows the process of setting up soft serial to swap the smart audio over to so UART 2 can be used for GPS. The video also shows the Betaflight settings I have used after upgrading the ESCs to 32 bit.

Adapting the FC to fit a conventional frame

The Tinyhawk flight controller has a non-conventional mounting pattern, so we first need to make an adapter plate to convert that mounting pattern to something which can be attached to a standard FPV frame. You can download the cad file for this template using the link below to cut or print your own. Alternatively, you can purchase them adaptor plate on the Micronwings website.   

Adapter Plate CAD File Info and Downlaod

On some frames, the adaptor plate can be mounted flat on the frame. To do this, you must ensure that your frame has gaps which line up with the mounting holes for the Tinyhawk FC. You may even need to file away part of the frame to accommodate the bolt heads which attach the FC to the adaptrr plate. In the example shown here, we have also cut away the unwanted part of the adaptor plate to clear the frame bolt heads. 


There may be some cases where you need to raise the adapter plate above the frame because there are no conveniently located gaps in the frame to access the bolt heads for the FC. In this case, please refer to the example images on the info page for the adapter plate.


Frame Fitout

For this build I have routed the wiring under the electronic components above the frame. I have also removed 2 of the frame stand-offs to accommodate the Tinyhawk FC. The motor wires are routed over the top of the FC to make it easier for soldering. The VTFX takes power from Vbatt and the GPS is powered from a 3.3Volt pad on the FC.

Fitout Components
* Goku HM600 VTX
* Matek R24-D ELRS Receiver with diversity antennas
* Diatone Mamba 1202 6500Kv Motors
* HQ Durable 3015 bi-blade propellers
* 2S LiIon battery pack (3000 mah Panasonic 18650 cells)
* Beitian Dual BN-220 GPS
* 3 Inch LR FPV frame

Softserial Setup

To free up UART 2 for GPS connection, it is necessary to swap the smart audio line over to a softserial port. The LED strip pinout is the best one to use as it has a physical pad on the board which the smart audio can be swapped onto. Also, smart audio only requires one line instead of 2, so it is always a good choice to swap over onto softserial. The A00 pinout is connected to the LED strip pad and the commands below can be used to enable soft serial
resource LED_STRIP 1 none
resource SERIAL_TX 11 A00

Once this is done, you can enable soft serial in the configuration tab and then in the ports tab, just swap smart audio over on to the softserial. The video linked above shows the detailed process for doing this.

Configuring 32 bit ESCs

Although not necessary, you may want to upgrade the AIO board’s ESCs to 32 bit instead of the default BlHeliS. To do this, you can use either JESC or Bluejay. I have a tutorial showing how to upgrade with JESC here and there are many videos on YouTube showing the process for upgrading with Bluejay. 

After upgrading your ESCs I suggest you follow my “BLHeli32 Bit Settings for BetaFlight 4.2” setup guide to correctly configure the Betaflight settings. This is also covered in the video linked above. However, in essence, the only deviations you need to make from this tutorial is as follows.

* In Step 1 of the guide,  Set both the Gyro Update Frequency and PID Loop Frequency to 4K. Also set the ESC protocol to DSHOT300 instead of DSHOT600. 
* Refer to the CPU load shown at the bottom of the Betaflight screen.  It should be showing less than 30%.
* In the CLI tab, type “tasks” and check Maxload for the Gyro and Pid loop. This value should be about 75%.

Battery and Weight

Frame Weight: 103 grams

Battery Option 1: 2S LiIon with Panasonic 3000mah 18650 cells

All up flying weight: 205 grams

Flight Duration: 15 minutes 30 seconds
(flying battery pack down to 5 volts)

Battery Option 2: 2S 550mah LiPo

All up flying weight: 135 grams

Flight Duration: 5 minutes 30 seconds