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Using the ToolkitRC WM150 Watt Meter

A Watt Meter is a useful addition to your tool kit if you are using electric motors, servos, or Electronic Speed Controllers (ESCs). There are a few different types available, but for our purposes, the WM150 from ToolkitRC is an affordable option. Specifically, a Watt Meter allows you to measure the current drawn from a power source, typically a battery, and calculate the power being dissipated. This is important because too much current will cause things to start melting and release the magic smoke from components.

In addition to measuring voltage, current, and power, the WM150 can drive a servo/ESC directly. This is handy when you are not sure whether the servo or the microprocessor is causing a problem and for measuring servo power requirements. 

Read our full review of the WM150 Watt Meter on Medium.

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Arduino Library for the Stewart Flight Simulator Platform

The Stewart Platform, also known as a hexapod, motion base or parallel manipulator, is a mechanical system that consists of a platform connected to a fixed base through six independently actuated legs. This arrangement allows for precise and versatile motion control in all six degrees of freedom (DOF): three translational (surge, sway, heave) and three rotational (roll, pitch, yaw).

In the context of flight simulators, the Stewart Platform is utilized to replicate the dynamic movements and sensations experienced by pilots during flight. It provides a realistic simulation of aircraft motion, enabling pilots and trainees to practice flying maneuvers, emergency procedures, and various flight scenarios in a controlled environment. By synchronizing the movement of the platform with visual and auditory cues, flight simulators enhance the training experience and help pilots develop their skills without the risks associated with actual flight.

The Stewart platform is used in car/flight/VR simulators, machine tool technology, animatronics, crane technology, underwater research, simulation of earthquakes, air-to-sea rescue, mechanical bulls, satellite dish positioning, the Hexapod-Telescope, robotics, and orthopedic surgery.

We will be using it to test our drone flight control hardware, IMUs and associated software. You can read the full Stewart Platform article on Medium.

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An Arduino DC Motor Dynamometer Shield— Part 1

We needed an instrument that can plot the voltage/thrust curve for any BLDC motor and propeller combination. We use Pulse Width Modulation to control the Electronic Speed Controller which drives the motor, and it would be nice to be able to relate the PWM percentage to thrust. Our first prototype used Force Sensing Resistors which will be compared to load cells. #arduino #fsr #dyno #shield

https://reefwing.medium.com/an-arduino-dc-motor-dynamometer-shield-part-1-54efd0c3e7e6

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An Arduino Library for the x-IMU3 GUI, IMU Data Visualisation Tool

IMUs with 3 sensors each measuring 3-axes, pump out a lot of data. It can be difficult to work out how your IMU is performing, which is why the free open source data visualisation tool from x-io Technologies is so great. It is available for all major operating systems (Windows, macOS, and Linux). #arduino #imu #datavisualisation #datavisualization

Read all about it in our latest article on Medium:

https://reefwing.medium.com/an-arduino-library-for-the-x-imu3-gui-imu-data-visualisation-tool-e5aaacf894a7

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OLED Displays are slow!

We have been prototyping an Arduino based Electronic Speed Controller and planned to include a 0.96″ OLED display. Tests on an Arduino UNO, clocked at 16 MHz, have shown that this display could best be described as sluggish! Even using SPI, printing out 3 lines of text results in a loop cycle time of 15 Hz. Quelle horreur! This prompted us to investigate further to understand the bottlenecks, SPI vs I2C speed, and whether there were any work arounds. #arduino #oled #SSD1306 #DFR0650 #SPIvsI2C

https://reefwing.medium.com/oled-displays-are-slow-2f422840d735

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How to Design an Arduino Electronic Speed Controller (ESC)

Having delved into how BLDC motors operate and provided an overview of trapezoidal sensorless control, we can bring it all together in the design of an Arduino ESC shield. This turned out to be much harder than we expected – now we know why no-one does it!

This series of articles was sponsored by PCBWay.

#arduino #shield #ESC #bldcmotor

https://reefwing.medium.com/an-arduino-nano-electronic-speed-controller-esc-part-1-4f65076fb2e4

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Create a Custom Part in EasyEDA

As part of creating the new Sumobot motor controller PCB I had to create a custom part which wasn’t already in the EasyEDA library. The part is a momentary switch from Jaycar. The process is pretty straight forward, design the schematic symbol, design the PCB footprint and then link the two. Should you ever need to do it – here is how! https://reefwing.medium.com/creating-a-custom-easyeda-part-c02abdd85653

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NexgenTimer Arduino Library

LiPo batteries are great for drones but you don’t want to over discharge them. To allow our Flight Controller to monitor battery capacity we used a non blocking scheduler and packaged our requirements up as an Arduino Library, NexgenTimer.

Our library is an amalgamation of the MillisTimer and ElapsedTimer libraries with some application specific examples and an extra Timeout class. It only uses functions from the Arduino core API and hence should work on all Arduino boards.

It can be downloaded using the Arduino Library Manager and you can read all about it in our latest article on Medium –

https://reefwing.medium.com/how-to-write-your-own-flight-controller-software-part-6-7ce0fa3e8008