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Showing posts from 2015

Automated sprinkling system using microcontroller

So I've been working on a concept to help my garden grow from what it is now something more substantial. It's really tough on the lawns to have two busy dogs and not enough water. So eventually I decided to buy 12V solenoid valve ( which can work down to 7V) and design a PCB board with the necessary hardware. So this board has the capability of temperature and daylight. So with this, it will be able to switch the sprinkler only at optimum timers of the year. I'll upload more pics once the finished product is working. Which is hopefully the next few days.

Automated sprinkling system using microcontroller

So I've been working on a concept to help my garden grow from what it is now something more substantial. It's really tough on the lawns to have two busy dogs and not enough water. So eventually I decided to buy 12V solenoid valve ( which can work down to 7V) and design a PCB board with the necessary hardware. So this board has the capability of temperature and daylight. So with this, it will be able to switch the sprinkler only at optimum timers of the year. I'll upload more pics once the finished product is working. Which is hopefully the next few days.

It's been too long: the rat race

So it's been at least a few months since I've written updated everyone of what the next plan for this project is. I realised that not being close to an open field has really dampened my motivation to fly my concepts as often as I should. So it's quite clear that I needed to find a new way for testing my custom flight controller and even though my work has taken much of my time in general, as new approach is needed. To change, I salute you.

Distractions unto to bigger things (quadcopter)

It's been awhile since I've actually touched my project. More responsibilities at work and now enrolled in a business school makes finding time for 'real' work quite difficult. And by the way, I've been learning Android development for school (business school) so I might come up with an application for this project in the near future. But nevertheless, I've had many chances to ponder on how I can speed up the development of this autopilot. It's been quite clear that flying a 2m glider is restricted to large fields which you have to drive to only when the weather is right. For prototype development, a slow turnaround for testing is your number one enemy. Trying to fly at work is also counter-productive because then time is taken off something work is not paying for. So the decision made to change the platform upon which the autopilot is been tested. We went from 2m glider, 60cm glider and now we're going quadcopter. You may think what!!!!! You can'

No more resisting the market trend. I'm developing a quadcopter

Yeah that's right. Everywhere you go, including some intern projects at my company, quadcopter drones is the current trend. The marketing success is simple. It's a lot cheaper and less complex and than a comparable RC helicopter. They're virtually no mechanical moving parts (expect the platform itself). And it's perfectly suited for camera attachment. So hot combination has spawned the quacopter drone revolution. I've always been against following a trend just for the sake of it. But considering that I need perfect weather test fly my flight controller only makes sense to start modifying my code to accommodate for a quadcopter. The controls are pretty straightforward and the design is incredibly simple. Another design dev coming up!

New miniscale aircraft concept

So I decided to build a new aircraft since my 2m glider only gave me limited flying options. This is was quite a quick project as all was designed in Solid Edge including the electronics. This enabled me to work out the mass and balance throughout the design process. The total weight sits at 250g. This includes autopilot and GPS. It's designed to have external servos and a shifting wing placement since it will have various payloads like a mini VGA camera. The electronics are housed nicely in the fuselage powered by a 850mAh 7.4V battery. I've removed the redundant magnetometer in the autopilot board. Still not sure on the CG placement, but from the crashed maiden test and the fact that the control moment arm is quite small, it's believed that the C.G. needs to be further aft from the wing main spar (which currently sits on the aerodynamic center).

There's hope for my drone - The FAA makes provisional drones ruling

So finally the FAA has released its take on how to regulate the commercial use of drones or unmanned aircraft on USA territory. It's mostly good news although, some companies (like Amazon) will not be too happy. The gist of the rules are as follows (copied from here ): Unmanned aircraft must weigh less than 55 lbs. (25 kg). Visual line-of-sight (VLOS) only; the unmanned aircraft must remain within VLOS of the operator or visual observer. At all times the small unmanned aircraft must remain close enough to the operator for the operator to be capable of seeing the aircraft with vision unaided by any device other than corrective lenses. Small unmanned aircraft may not operate over any persons not directly involved in the operation. Proposes a microUAS option that would allow operations in Class G airspace, over people not involved in the operation, provided the operator certifies he or she has the requisite aeronautical knowledge to perform the operation. Daylight-only operati

So now I need a pilot licence for a 200g drone

So the game space has changed. The South Africa CAA ( SACAA ) has come out guns blazing drafting regulations regarding remotely Piloted Aircraft/System (RPA/RPS). One thing was clear, this massive chaos that growing in this country had to come to an end. Already, the general population of stakeholders in the civilian airspace have a very nonchalant attitude when it comes to safety and security. So the introduction of aviation regulations towards the growing market of drones is a much needed intervention.

Method for coordinated turn

So I've been battling to establish a simple method in mimicking rc control inputs during a sustained or coordinated turn of the aircraft. This is quite important as it's not the same as stabilizing controller which reacts to dynamic events while having a static reference. A coordinated turn has a dynamic reference which is coupled to the turn rate experienced which directly related to the speed and the roll command inputs. But since the turn rate of the aircraft can be extracted from the gyroscope measurements, it can be stated that post processing of these signals (using a low pass filter) should give an indication of whether such method can be used alongside a stabilizing controller. This is such that once a coordinated turn can be achieved even in adverse weather, waypoint tracking is closer to being realised. Amendment 15/1/2015: It was found after careful analysis of the flight dynamics of a simple aircraft that gyroscope measurements was not a fool-proof way of