Design, Build, Test, Iterate

Posts Tagged ‘tricopter’

Tricopter chassis v0.3

After a month-long hiatus after the crash, I redesigned the tricopter chassis. The aluminum arms are now foldable, and the motors are closer to the center of the chassis (I have yet to trim the arms to a shorter length). There is room for the new and bigger ESCs underneath the other electronics.

How to crash gracefully as components melt off your electronics in midair

Actually, I don’t really know how other than to build a tricopter as awesome as mine. Earlier last month, I flew my tricopter up to about 80 feet above the ground to test its range as well as controllability. Due to a shortage of my usual propellers, I had been flying with an oversized tail […]

Removing a bad cell from a lithium-polymer battery

One of the cells in my lithium polymer battery rapidly started losing capacity a few days ago. I ordered two new batteries, but I needed power in the meantime. It was trivial to open up the battery and remove the faulty cell, since the other three cells were fine. The battery is now effectively a […]

More flight videos

Ever since I achieved stable flight, I have gone outside for flight testing almost every day for the past week. Check out some videos after the break.

Tricopter controlled flight!

Or, the best one-line bug fix ever. For two months, I had been thinking I was running my flight controller at 166 Hz while actually running it at a measly 31 Hz. I don’t want to go into detail about how that happened, but I have fixed the problem, and now it works. I am […]

A better alternative to position PID for multirotor control

Some systems can be controlled with a simple P controller, where a given offset is translated directly to some actuator output. Other systems, like the flight orientation control of micro aerial vehicles (MAVs), may require a damping term on the position to prevent a divergent oscillation of the vehicle’s angular position. However, the D controller […]

Custom firmware for multirotor ESCs

Multirotor flight control requires an update frequency on the order of hundreds of cycles per second. Most ESCs sold for RC plane use are capable of reading a PPM input at frequencies of up to 400 Hz, but they do not translate the PPM input to motor speed output at the same rate. tl;dr: Flash […]

Tricopter chassis v0.2 complete

The new chassis is now complete!

Reduce noise on Arduino 400 kHz I2C with external pull-up resistors

Yesterday I wrote about how sensitive the I2C bus was to noise induced by merely touching exposed leads with a finger.

Noise on the I2C bus killing communication?

Originally, I soldered the gyro and accelerometer breakout boards directly to the tricopter’s main board, thinking that using headers would make them wobbly and unreliable. Recently, I have found myself wishing more and more that the boards were easily separable, so I rewired the board (it turns out quality headers don’t wobble at all).