Fatshark SharkByte TX5S.1 75mm 1S using Boost Regulator

By jason.gauruder on Aug 20, 2021

7  390  0

dont do this boost regular stuff anymore!!!

get the hdzero lite whoop bundle instead!!!

NBD Cockroach Brushless Extreme-Durable Frame 75mm
BetaFPV Canopy for EOS2
NBD Hummingbird Pro 1s AIO FC, BT2.0 connector
NBD 0802 18000kv (direct soldered)
NBD Azi Tri-blade 40mm
GND 450mah 1S w/ BetaFPV BT2.0
SB Whoop Board TX5S.1 w/ Dipole antenna
RunCam Shark Byte Nano Digital FPV Camera, w/ default length mipi cable
Pololu Adjustable Boost Regulator 4-25V

note:I previously used the pololu model #791 which looks the same yet it has a lower max output voltage of ~9.5v . that #791 Regulator would only allow me to push a battery down to about 3.2v before video would give out. the #799 Regulator is superior in that I can drive a 1s battery down to 2.8v or lower. (not that it is good for a lipo cell, but I like to be able to drive the battery lower than 3.2 v)

I set Boost Regular to approx 60% of its max setting (approx 7V volts) using the built in trimmer potentiometer
The Pot has physical "stops" as you turn clockwise (higher voltage to ~25v max) or counterclockwise (lower voltage to ~4v min). You can test various settings on the upper limits and you will see at what setting the VTX board powers up (but does not output video) and gradually increase until the red and blue lights come on the VTX. Do not make changes using the POT while power applied (not sure what will happen, but I tried to avoid doing so). I estimate for me it was about 60% of the total available physical clockwise movement that is allowed.
Soldered Vin and GND to FC input leads
Soldered Vout to TX5S.1 "V" (Voltage) pad
GND is shared/common from input GND ("negative" on FC input lead) and TX5S.1 "G" (ground) pad
No Capacitor used in this application.

TX5S.1 using FC UART2 TX/RX pads (per SB instructions TXRX and RXTX)
Set in betaflight that UART2 for MSP and baud 115200
Do not use SB latest "canvas" mode firmware - since NBD Hummingbird only runs their custom beta flight build @ v4.1.5 and cannot yet run 4.2.8 or later. I could not get any OSD to display until I reverted back to Rev 20022021 in the "archived Firmware" section :

The BetaFPV canopy is hacked up to provide better clearance around/over the TX5S.1
The camera sticks out several mm. Better options surely exist (or 3D print, thingiverse, etc), but this is what I had on hand
A very boring flight uploaded to youtube. but proof of 1S batt voltage used.

I have a handful of backyard flights and a couple indoor. I do not know yet the long term longevity of either the boost regulator or running the TX5S.1 off of a boost regulator. I do know that there is loss (heat) in the conversion/boost process.

Outdoor flight example :



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