DIY 4 in 1 Module with ER9X

This is a setup guide for the 4-in-1 radio module from

This radio module can speak almost every protocol on the market today. You can find the details of each protocol along with the full documentation and the firmware on the github page here:

Prepare the multi-module

When you get the multi-module, it comes without a case.

So I went ahead and printed this case by nebbian, download it here one from...

The Ultimate Micro Quadcopter Guide

This article is an intro to the awesome world of micro quadcopters. I've tried out a few and share some thoughts below.

Eachine EX100

The Eachine EX100 is a ready to fly micro FPV racing quad. It's a fun little quad with a 4 to 5 minute flight time. It comes basically ready to fly, just flash BetaFlight and you're ready to go. I also really like how you can have your normal BetaFlight acro mode!

Judging by the video, I to brush up on my pilot skillz :)

Perfect for indoor flying, on...

Geeetech Prusa I3 X Build Guide

I just got my first 3D printer, the Geeetech Prusa I3 X. This post details my experience as a 3D printing noob: unboxing, assembling and using this 3D printer. First, let me show you what this printer can do.

Here, I'm printing an Atlas statue to hold up my colleague's monitor.

Safety tips

  • Never plug or unplug cables from the controller board while the board is powered. This can damage the board or motor controllers.

  • This thing gets HOT, don't let little kids touch the build...

BetaFlight Kiss Flight Controller

This guide will show you how to install BetaFlight on your Kiss FC.

When I told we were interested in supporting the KissFC in BetaFlight, the were kind enough to mail me one. At the same time, I wasl talking to Joshua and he also send me a KissFC! Thx guys. Y'all are the best. I'm going to pass one of the KissFC's on, so we have some more developer's with one in their arsenal.


Motor order

BetaFlight Motor Number -> KISSFC PAD LABEL
1 -> 3
2 -> 2
3 -> 4
4 -> 1

J-Link Getting Started Guide

These are my notes on J-link debugging, mostly for ARM.


Head over to the jlink downloads page to grab the latest software for your platform.

Install the package then connect your debugger.


I just used some Dupont jumper cables to connect the SWD lines. You could get one of these breakout boards, but that seems unnecessary.

You would connect the Dupont cables like this. Note that when using the grey 20 pin Jtag cable, the pinout should be viewed from the "back".



Airbot F3S AIO Flight Controller and Typhoon 4-in-1 ESC

This is a quick overview of the Airbot F3S AIO Flight controller and Typhoon 4-in-1 Pro ESC.


The F3S is an upgraded, F3 version, of the OZE32 which is a PDB, MinimOSD and flight controller all in one. I have a beta version of the F3s, the final version is gold plated.

The button on the top will switch the USB/UART between the flight controller and OSD. No more messing with dip switches, woohoo!

The integrated OSD is a MinimOSD, not directly connected to the flight controller. This...

FlySky i6 Radio Setup and Hacking Guide

This is my unboxing, review and hacking guide for the Flysky FS-i6 2.4ghz radio transmitter.

I started this project thinking I could easily use the 4-in-1 DIY transmitter module in the radio, but this turned out to not be the case. Instead, I've start working on porting OpenTX with serial support for the 4-in-1 DIY transmitter module. Devs, help me out here!


Here's the box.

Inside is the cool protective plastic thing.

BetaFlight Spektrum Satellite Receiver Guide

Receiver Setup

Here is an example Spektrum RX Satellite setup guide. I'll show you how to bind it with your transmitter using betaflight version 3.1.6 and newer. I'll be using an OmnibusF4 in my example.

Serial RX

On the OMNIBUSF4, the UART1 RX pin is available for use on 3 different headers, only one of which can be used at any given time: - SBUS port (via inverter), this pin is also shared with the PPM pin. - Spektrum sat header (no inverter) - UART1 header (no inverter)

Spektrum Binding...

Omnibus Flight Controller and Airbot Typhoon 180 Miniquad Build

This is a review, build and setup guide for the Airbot Typhoon 180 Miniquad with the brand new OmnibusF3 flight controller.


The OmnibusF3 flight controller uses the MPU6000 over SPI for the best possible flight performance. If you haven't already seen it, you should checkout Josh's awesome video on different IMUs. Along with the MPU6000 are a barometer and an AB7456 OSD chip (an upgraded MAX7456) for the BetaFlight integrated OSD.

The OmnibusF3 has an SDCard for blackbox...

FPV Goggle Guide

I bought a bunch of FPV goggles and tried them out so you don't have to. This article is a review and comparison of all these goggles.

Top Picks

Here are the goggles I would buy and why. Click the summary test, scroll down or use the navigation on the left to find a detailed review of each.

Best Value Goggles

Update May, 2017: The Eachine VR D2 Pro goggles have just been released. The non-pro version of the VR D2 goggles were my goto goggles as they're cheap, diversity enabled, have a large...

HobbyKing Quanum V2 Pro Goggles

This is a build guide and review of the HobbyKing Quanum V2 Pro Goggles.

Here they are assembled with my DYS X160:


Overall, these goggles offer great performance at a great price. They are light, easy to assemble and should work fine with glasses. If you're looking for a first (or second or third) pair of goggles, this is a great option.

As for the display, I like the single monitor style a bit better than the two monitor goggles (like Fatsharks) since the single monitor gives a...

Drone Building 101 with the HobbyKing FPV Starter Setup

At Maker Faire Bay Area 2016, David, Jack, Huned and I built a drone with the help of some kids. This is the story of that drone.

Let's start with the results. Here is some video of the drone flying with the BetaFlight 3.0 firmware.

And chasing the drone with the x200


Here are all the parts we used:

KingKong 260 FPV Frame Set (Pair) w/ props, $17.69

STM32 hardfault debugging

Programming a microcontroller is a bit different than programming on a PC. Error messages aren't nicely propagated to a terminal or GUI.


Error states are however, reported via register values that can be used to easily find the source of the exception. Keeping it open source, I will be using OpenOCD with Eclipse to demo this.

The general idea is to:

  • Jump to a specific place in the code when the exception occurs (the HardFault handler)

  • Preserve the register values at the time of the...

Rctimer BeeRotor u210 mini quad build, setup and review

This is a build and setup guide for the new BeeRotor u210.

Here's some footage from the maiden flight:


Everything you need except the transmitter and receiver, battery and charger is included in the kit! You'll also want some good goggles if you're just getting started.

This basic setup is great for a beginner:

FlySky FS-i6 with iA6B Receiver, $53

AirBot Flip32 F3 AIO Lite and Typhoon 4-in-1 ESC

This article is a review and guide for the following components:


Airbot F3AIO-LITE F3 flight controller with 16MB of flash.

Airbot Typhoon 4x20A 4in1 ESC which is 4 littlebee ESCs on a single 35x35mm PCB.

RTFQ Power Distribution Board which works in tadem with the flight controller to provide power along with voltage and current sensing.


The key differentiator between the BeeRotorF3 F3AIO-LITE is the 16MB of flash and the full size, 2.54mm pin headers, as opposed...

DYS X160 v3

This is a review and setup guide for the DYS x160 v3 miniquad.


This is a fun little miniquad and at 138g without a battery, no registration (in the USA) is required to fly. The quad itself is great value at a little over $100 on It is quick and nimble on BetaFlight 2.7 and with the un-changeable amount of camera up-tilt, it might be a little much for a beginner, but for a second quadcopter, this thing is fun! Compared to the BeeRotor 160, it is a little bit lighter, fully...

Turnigy Reaktor 250W Charger

This is a review and user guide for the Turnigy Reaktor 250W 10A 1-6S Balance Charger


Here's everything that comes in the box:

Features include:

  • IR measurement

  • Automatic cell count detection

  • Temperature based fan control

  • Configurable max voltage per lipo cell, up to 4.3v


The Reaktor 250w is an amazing deal at $39.99, given it's features are comparable to the much more expensive iCharger 106B which runs $89.99.

Parallel Charging

Parallel charging makes it possible to...

HobbyKing Graphene and Bolt High Voltage LiPo Battery Analysis

Hobbyking sent me some 3s 2200mah Graphene and 4s 1300mah Turnigy Bolt batteries for testing and review. I flew them along with some of my other batteries and compared the data. Here's what I found.

Batteries Tested

Shown in the photo above from left to right, these are the batteries I tested:

1x Lion Power 1500mah 40c 3S $13.59

2x TBC 2200mah 25c 3S ~$8.20

2x Turnigy Graphene 2200mAh 3S 45C LiPo Pack w/ XT60 $23.94

4x Turnigy Bolt 1300mAh 4S 15.2V 65~130C High Voltage Lipoly Pack (LiHV...

BetaFlight in-flight PID tuning

I've setup my 9x for in-flight-adjustments, allowing me to tune my PIDs while flying. I have OpenTX installed on my 9x.

Since my only 3 position switch is already in use, I've setup the dial like a 3 position switch. Moving the dial will switch between adjusting P, I and D. I only adjust the roll and pitch axis, yaw will need to be tuned separately.

I've mixed the TRN and GEAR switch in my radio so that when the GEAR switch is down, flipping on TRN send the channel high and when GEAR is up...

Drone Building at Maker Faire Bay Area 2016

If you live in the SF Bay Area, come to Make Faire on May 20-22 and build a drone with me!

I'll be hosting an exhibit called Drone Building 101 where I'll be helping folks build their own FPV mini-quad. We'll be building stuff like this little 160mm FPV racing drone: BeeRotor160 Build.

Fill out this google form so I know you're coming:

Here are some ways you can join in on the fun:

  • If you're into drone building and would like to help others with their builds...

Rctimer BR-X200 Mini-quad Build, Setup and Review

This is a review, build and setup guide for the Rctimer Beerotor X200.

Here is some chase video filmed with the x200 on stock PIDs, BetaFlight 3.0

All up weight is 323g for a power to weight ratio of approximately 10:1.


Here's everything you'll need for the quadcopter:

We've got:

x200 Frame, $29.99
4x XDrone 20a ESCs, $43.96

AVR Dissassembly


Install avr-libc via homebrew on mac:

brew tap osx-cross/avr
brew install avr-libc

Install radare2

brew install radare2


Convert the hex to bin

avr-objcopy –I ihex –O binary hello.hex hello.bin

load with radare2

r2 -a avr hello.bin

or output assembly, for the atmega328p:

avr-objdump -j .sec1 -d -m avr5 test.hex

where -m specifies the architecture of your chip from:

Victory230 FPV Mini-quad Setup and Review

This is a setup guide and review of the Rctimer Victor230 FPV mini-quad.


If you're thinking about getting a Vortex Pro 250, think again. The Victory230 will out-fly and out-perform the Vortex any day of the week. Though it's prop-span is 20mm smaller, the Victory230 has bigger motors, ESCs that handle more current, an open source flight control board and OSD that can be easily upgraded. Plus, it's almost half the cost. This is amazing.

The Victory230 includes everything you...

FrSky RX SBUS and Frsky DJT Module

This is a review, setup guide and comparison of the two Airwolf DIY FrSKY Receivers (F801 and F802), both paired with the DJT Transmitter module in my 9x. This article also takes a look at the Naked X4R receiver from FrSky.

Note that the DJT module will not bind with the X4R since it uses the newer D16 mode. You'll need to get the XJT module or a Taranis, both of which support D8 and D16 modes, to bind with the X4R. See the compatibility section for details.

Update Aug, 2016: There is a new...

HMDVR and Eachine ProDVR FPV Video Recorder

This is a review of the new HMDVR FPV Video Recorder. Note this also applies to the Eachine ProDVR, which has the same internals.

If you're looking for a recording device, I suggest you also checkout my GO FPV project, which turns your Android phone into FPV goggles and a DVR.


Here are some videos. I recorded both on the lowest resolution (640x480) to roughly match the video quality being transmitted of the 5.8ghz link.

Here's a screenshot of some NTSC video output from my Beerotor...

Rctimer BeerotorF3 Flight Controller

This is a review and setup guide for the new BeerotorF3 (BRF3) all-in-one (AIO) flight controller from Rctimer.


Update Aug, 2016: The new Omnibus flight controller is out. If you're looking for a high performance flight controller with a directly integrated OSD, this is the board for you.

You probably know why having an OSD that displays current consumption is so important, but I'll reiterate it anyway. A current sensor measures the exact amount of battery that has been used and...

Flying Sony NEX Micro 4/3rds Camera

So, you want a flying camera to take videos of you and your awesome friends doing amazing things. You've thought about getting one of those pre-built drones by DJI or 3D Robotics, but those are expensive little drones that only carry weak little cameras.

Building a giant rig to carry your full frame DSLR isn't ideal either, because it will need to be huge and therefore less portable.

So what should we do? Build something to carry our NEX-5T micro 4/3rds camera! This camera weighs 397g with the...

Q600 Quadcopter

In this review, build and setup guide we will walk through building and configuring the Q600 quadcopter from Rctimer.

Later, I'll mount an ASP Gimbal on the Q600 to carry my NEX-5T.


For the full review, checkout the Flying Sony NEX Micro 4/3rds Camera article.

Overall, the build quality is great. The integrated PCB / PDB body makes assembly a breeze.

The 30mm OD carbon tubes are super robust. The landing gear is tall enough to accommodate the ASP gimbal and a NEX-5T.

Since there...

ASP micro 4/3rds Gimbal and SimpleBGC 32-bit Gimbal Controller

This is a detailed build and setup guide for the Rctimer ASP 3-Axis Brushless Gimbal.

Here are the parts I used:

Rctimer simplebgc 3 Axis Nex-GH5 Brushless Gimbal - $200
AlexMos SimpleBGC 32-bit Brushless Gimbal Controller w/ Plastic case - $171

Total Cost: $371

I'll be mounting this on a Q600 quad-copter.


Here's everything...

PixHawk Flashing and Setup

This guide will show you how to install, flash and configure the PixHawk. I'll be using Rctimer's distribution of the PixHawk, which is called the FixHawk. From now on, I'll use these terms interchangeably. The FixHawk will be installed and configured in an Rctimer Q600 quad-copter, which I highly recommend if you're looking for an awesome frame, but these directions should apply to any quad-copter installation and configuration.


The PixHawk hardware and software is an open source...

BlHeli ESCs

This guide will show you how to flash BlHeli and the BlHeli bootloader so they can be programed via CleanFlight or BetaFlight pass through programming in BlHeli Suite.

What is BlHeli?

BlHeli is firmware that runs on some Atmel and SiLabs ESCs, supports OneShot 125, and is designed for multi-copter performance.

BlHeli Suite is the companion application (windows only) that allows one to flash and configure BlHeli ESCs.

The BlHeli Bootloader is part of the BlHeli firmware that is installed on...

BlHeli ESC Upgrading and Configuration

This guide will show you how to configure your ESCs with the optimal settings for use with OneShot125, CleanFlight or BetaFlight.

Download the latest BlHeli Suite from here:


It is possible to connect to your ESCs in a variety of ways. I think the easiest way to connect, if you've already identified the microprocessor and flashed BlHeli (with the bootloader) is pass-through programming via CleanFlight or BetaFlight.

If you don't have the bootloader installed...

BlHeli CleanFlight ESC Calibration

This quick guide will explain how to calibrate your ESCs so they throttle up evenly.

Why Calibrate ESCs?

Joshua Bardwell explains in these two videos why this is important



How to Calibrate

The general idea is to "program" the ESCs via the flight controller to tell them what the minimum and maximum pulse width is that they should be expecting.

Programming by TX

This will only work if you left the Programming by TX option turned on in BlHeli. If you turned this off, you'll...

Rctimer Micro 160 BeeRotor Build, Setup and Review

This is a review and build guide for the BeeRotor 160mm from Rctimer.


Here's some flight-cam video, recorded on my goggles with a HMDVR. BetaFlight's Air Mode is magic.

It hovers at a 1/3 throttle

158g without a battery


Everything you need except the transmitter and receiver, battery and charger is included in the parts list below. You'll also want some good goggles if you're just getting started.

This basic setup is great for a beginner:


Flashing SiLabs xRotor 20a with BlHeli via C2 4w-if

This guide describes how to flash the BlHeli and the BlHeli Bootloader to XRotor 20a ESCs so that they can be updated via CleanFlight and BetaFlight after installing them in your multi-rotor, without unplugging them from the flight controller!

There are two types microprocessors used on ESCS, one is made by Atmel and the other by SiLabs. Since the XRotor 20a uses a SiLabs processor, these instructions are generally applicable to other SiLabs based ESCs. You'll just need to identify the C2 interface...

Rctimer OZE32 / RTFQ Flip32 AIO Integrated Flight Controller Review and Setup

This article is an in-depth review and setup guide for the Rctimer OZE32 aka RTFQ Flip32 AIO.


Rctimer has just released a new flight controller (FC), the OZE32. This flight controller has all the hardware on a normal Naze32, plus the two components I add to all of my multi-rotors -- a current sensor and MinimOSD. Also included is a switch that changes the connection of the on board CP2102 UART/USB adapter between the flight controller and the OSD. This means you don't need to buy...