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Is PPM Analog or Digital?
Since I am a huge fan of answering questions when they are asked, here is my answer to “Is PPM Analog or Digita?“ The easiest way to determine if electrical signal (and PPM in case of RC usage is electrical) is analog or digital is to check how many voltage levels are used. If signal…
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Damaged motor: broken off magnet
One of the things that can happen to brushless motors, specially outrunners, is broken off magnet. Stronger crash, or even extensive vibrations, can cause one one small magnets located in motors bell to tear off. After all, they are only glued to rotating part of motor. Symptoms are: If magnet stays inside motor, it will…
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How to program ATtiny85 with Arduino IDE?
What is ATtiny ATtiny is a fimily of microcontrollers by Atmel, the same company that provides ATmega series used widely in “real” Arduino. Comparing to ATmega, ATtinys are much simpler, smaller (usually), with less features. But also cheaper, easier to connect, using less energy, and trust me, in many many cases you do not need…
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Read RC PWM signal with Arduino
Arduinos are cheap and simple development board. You can do a lot with even the simplest of them. For example build you own quadcopter and flight controller (after all MultiWii = Arduino + MPU6050). Of course, this is not as simple as one might imagine and there are few (actually a lot) obstacles that needs…
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Note on Arduino Uno servo jitter
Yesterday I discovered very nasty feature of Arduino Uno (and all other AVR ATMega328 boards) when using servos. Although official Servo library states that it can support up to 12 servos on Arduino Uno (more on advanced boards as Mega), it does not say much about quality of PWM signal. Since all connected servos (in…
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Detecting Cleanflight PID tuning issues with Blackbox: not enough P
This is third part of Cleanflight PID tuning tutorial with Blackbox. Previously I’ve showed examples of: Excess P gain, Excess D gain, This time it is time for something slightly different: not enough P gain. Usually this problem can be identified without any log analysis. Symptoms are quite visible: multirotor is sluggish during maneuvers, has…
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Detecting Cleanflight PID tuning issues with Blackbox: excess D gain
Welcome to second part of Blackbox PID tuning tutorial. Last time I have showed few examples how excess P gain might look like. Today I will write few words about next common PID tuning problem: too much D. Derivative (future) part of PID controller is very useful, since it allows to smoothen control loop output…
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Using transistors as switches
I think all popular computerized DIY devices like Arduino, Raspberry Pi or any other microprocessor/microcontroller based boards has one common drawback: low output current. Few miliamps per pin. While this is enough to light a single LED or provide input to other electronics device, it is far from enough to run a motor or power…
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Problem: no OSD when camera is connected on minimOSD MW OSD
Problem When camera and minimOSD are connected to video transmitter, minimOSD is not overlaying OSD data. If camera is disconnected, OSD data is transmitted. After connecting camera, only camera image is transmitted. Possible Solution Check if camera and minimOSD are using the same display system. Usually monitor/goggles and video transmitter does not care very much…