Category: Uncategorized

One of the values that describe LiPo batteries used in RC crafts is so called C rating. For example: 3S 1300mAh 45-90C. Or 3S 5000mAh 25-30C. Or 4S 1300mAh 65-95C. S is simple, it tells the voltage. mAh or Ah tell capacity. But what about C rate? According to Wikipedia is can be described as:…

New release of iNav is at the doors. Today I took testing version for a spin and tried few navigation scenarios. For example, transition for Position Hold to Return To Home with landing. It looked like this: It behaved fantastically: nice accuracy, precise landing. There were few wobbles on descend, but that was caused not…

Most people in RC hobby knows that receiver and transmitter antennas should match polarization. But what would happen if there was a mismatch? For example when transmitter uses linear vertical and receiver circular left hand? There would be a loss of power, attenuation. How much? Look at table below. Remember: -3dBi means half of power is…

Cleanflight is an awesome piece of software for STM32 based flight controllers. But Cleanflight has one very serious flaw that makes its usage on bigger drones at least problematic. Cleanflight sucks in GPS and barometer support. Sucks a lot. It can handle Position Hold (somehow), Return To Home (barely) and Altitude Hold (oh man, up…

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…

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…

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…

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…

FrSky sells 2 small Taranis compatible receivers: X4R and X4RSB. By default, they offer only PWM signal. 4 channels on X4R and 3 channels plus S.Bus (16 channels over S.Bus) on X4RSB. And that is problematic. Many flight controllers does not support S.Bus very well (no inverters) or just does not offer enough UART ports.…