Review: HGLRC Zeus35 AIO FC

HGRLC Zeus35 is the updated version of the famous Zeus All-in-One F4 board. Lets take a look at what has been changed or added to this board and why is this board so interesting.


Input Voltage: 3-6S
FC Firmware: BF HGLRCF411(HGLR)
ESC Firmware: BLHeli_S
Installing Hole: 20x20mm/M3 or M2
Dimensioms: 40x32mm
Weight: 9.8g

F411 Flight Control
CPU: STM32F411
MPU: MPU6000
OSD: Support
BEC: 5V/2A
BlackBox: 16M

35A 4in1 BLHeli_S ESC
Current Sensor: Support
Constant Current: 35A
Peak Current: 40A (10s)

Package Included:
1x Zeus35

Recommended Parts:
Motor: 1408/1407/1306/1106
Propeller: 2-5 Inch

Zeus35 AIO FC package contains the FC board, rubber grommets, XT60 connector with 14AWG silicon wires and optional 18AWG pigtail with XT30 connector. There are also two low ESR capacitors included – one 1000uF and one 220uF. Both are rated for 35V (6S).

The weight of the Zeus35 is only 9.8 grams. Thats pretty lightweight in comparison with other similar AIO boards (Sunrise Cicada AIO 30A ESC & F4 FC – 22 grams, Airbot Nox AIO 35A ESC & F4 FC – 22 grams)

Evolution of the Zeus

HGLRC Zeus35 became larger (40x32mm) than its predecessor Zeus 15A (35x32mm). Zeus35 weight also increased from 6.5 to 9.8 grams. All this is due to the twice as more FET driver chips and increased board size to accomodate these FET’s. Zeus 15A had 12 FETs and Zeus35 has 24 FET drivers. Thats how it handles the 35A currents.

On the one side of the board there are solder pads for UART2 and SBUS that are reserved for receiver. There are also Buzzer and LED control pads as well as S5 signal pad.

On the other side of the board you can find the solder pads for VTX and FPV Camera. TX1 pad is reserved for VTX SmartAudio/IRC Tramp control (or can be used for GPS and any other device. See the Softserial configuration below) . 

USB socket is secured with epoxy – it will not come off by plugging and unplugging the USB cable.

The heart of the ESC is Silabs BB21 MCU and Toshiba TPN2R203 FETs rated @45A, so the specs of the ESC are right.

Zeus35 has current sensor, the one that was lacking the previous version of Zeus FC.

The mounting holes are M3 diameter and can be downsized to M2 by adding the included rubber grommets.

HGLRC Zeus35 basic connection diagram:

Receiver connects to the UART2, VTX SmartAudio control to the UART1

Alternative HGLRC Zeus35 connection diagram if you want to connect Receiver, GPS and VTX SmartAudio

GPS is connected to the UART1, Receiver to the UART2 and the VTX SmartAudio to the SoftSerialUART3.

In order to set up the Softserial you need to enable the Softserial option in the Configuration tab in Betaflight Configurator:

Then remap the resources by entering these commands in the Betaflight Configurator CLI:

resource MOTOR 5 none

resource serial_tx 11 B03

Don’t forget to save the configuration by entering save command!

After this you can see additional UART port as SoftSerial1. Now you can set this port for VTX SmartAudio control.

Available @ 




  • Low profile installation
  • Lightweight FC+ESC combo
  • Supports 3-6S 
  • Blackbox flash
  • Current sensor


  • Only 2 UARTs are available (but can add softserial port)
  • Will not fit some of the frames due to the size



HGLRC Zeus35 is highly integrated, ligtweight AIO FC+ESC board. It weights only 9.8 grams and it is the lightest AIO ESC and FC board for 20x20mm mount pattern.  However due its bigger size 40x32mm than its predecessor and can probably will not fit into all the 20x20mm mount size frames. 

Zeus35 ESC provides 35A (45A burst) current and supports 3-6S battery input. This makes it competitive board for any light 5″ quadcopter. While it probably will not  fit the heavy racing setups, but will work on the quadcopters ranging from 3″ to 5″.

Zeus35 has the same size 16Mb BlackBox flash chip as its predecessor, but has current sensor added to the board. 

There is only 2 UART ports available on the HGLRC Zeus35 FC. First one is reserved for receiver and the second one is for the VTX control. This leaves with no UARTs for GPS or DJI Digital FPV system. However you can resource the S5 pad as Softserial port and use it for VTX SmartAudio freeing one additional UART port for GPS or DJI Digital FPV system.

I wish the HGLRC would add solder pads for additional UART in the future iterations of the Zeus flight controlers.

2020-02-16: Article created
2020-02-21: Updated with Softserial info

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