RCHacker.com - Radio Control for Engineers, Hackers and the advanced Hobbyist

023 Studying hard and waiting for the mail.

posted Mar 20, 2013, 6:49 PM by Marc G

I have been very busy lately reviving my Engineering skills. My background is Aerospace and more so Software Engineering and during my studies we covered every branch of engineering including hardware design. It has been a few years since I worked as a software engineer, and even more since I did any hardware at university. After a number of years travelling and doing completely unrelated jobs. I am amazed how technology has progressed, including the software tools to make things happen. It seems we are in a brave new word where it is affordable to design and get made your own PCBs. Microcontrollers are amazingly cheap and powerful and with an Arduino and a bit of hacking it is possible to do re-flow soldering in a hacked toaster oven. Finally the internet: 95% full of crap but if you search for it you can learn anything.

While some of the RC technology out there is brilliant. FrSky, KK2, OpenPilot are a couple that come to mind. So much of it is just utter crap, cheaply made and full of bugs. There are many products where a bit of good engineering can make a huge difference. FPV gear is one.

So I want to work my ass off and get some products of my own out there. I have many ideas but I'm not going to promise them all at once.

My design philosophy will be: Not what I think you want or even what you think you want, but what I want. If you like it, great. If not tough.

If I go broke trying at least I will have some nice gear. :)

Very early days yet, but I will continue to share my progress on YouTube.

My first set of PCBs (the Switch) is apparently on its way. Unfortunately postage is far too slow and sometimes unreliable to Ecuador... :(

022 FPV to the edge of space.

posted Mar 7, 2013, 7:32 PM by Marc G [ updated Mar 7, 2013, 7:34 PM ]

All I can say is: Simply brilliant David.

Link to David's project page here:

021 Introducing the Switch

posted Feb 18, 2013, 9:07 PM by Marc G [ updated Mar 3, 2013, 9:03 AM ]

So it turns out that an initial purchase of parts for a prototype run of my diversity board would be in the $500 range. For me is a bit much when I have not even tested the postal system from the states. So I decided to start with a simpler project that has lower initial costs.

Introducing the Switch:

What does it do? It is a multipurpose digital switch. Six high voltage, high current MOSFETs controlled by a microcontroller. There is the provision to accept control signals via PWM, PPM, SPI, serial, I2C or USB. The board has been laid out so it is easy to attach a FrSky D4R-II receiver, OpenLRS or the DIYDrones IMU. Each MOSFET can be controlled via hardware PWM and by combining this with voltage and current sensing a constant voltage or current could be provided to each output. Finally it will be Arduino Leonardo compatible in order to make programming as accessible as possible. Like the Freetronics Leostick (which it is based on) it will be an open hardware design.

I plan to write software so it will be easy for non programmers to quickly configure their RC gear to trigger each switch.

Possible uses:

High power intelligent LED control.

Brushed motor control.

Pyrotechnics ignition.

I have a bit more work to do optimising the layout to make it easy for hand soldering before I will get a prototype PCB batch done. The circuitry for the current sensing is so far untested but the board design allows for a bit of experimentation here.

Watch this space.

020 Reaktor 3D in the mail.

posted Jan 30, 2013, 8:08 PM by Marc G [ updated Mar 17, 2013, 6:16 AM ]

With all these multirotors I am spending more time fixing them than flying, so I have decided to lash out and get myself into 3D.

Now that HK have fixed their postal issues I have an EPP Reaktor 3D in the mail. It seems pretty popular and looks to be a nice design, it even has a real airfoil. Something that I can fly in and out of the trees in the small yard and it will not break in a crash.

Don't tell the misses, I'm going to tell her I made it out of scrap foam :).

If you want to support my work here are my affiliate links for the other warehouses. USA, AUS, NL and UK.

It costs you nothing and I get 5% from the sale to spend on rc stuff.

From the reviews and comments here is what I chose for the hardware:

HobbyKing 2614 Brushless Outrunner 2000KV

UPDATE: This motor is a piece of shit, recommendations on HK are also crud. The base of the motor is very thin and failed due to vibration.

I have a much bigger motor from my FPV Raptor on board now that is super powerful but I get short flight times.

A Turnigy Park300 1600kV is in the mail.

Mystery 20A Brushless Speed Controller (Blue Series)

HXT500 5g / .8kg / .10sec Micro Servo

Turnigy nano-tech 460mah 3S 25~40C Lipo Pack

TGY Slow Fly Prop 8*3.8SF

TGS Sport 8x3.8E Precision propeller

TGS Sport 8x4E Precision propeller

Slow Fly Paddle propeller 8x4 (GWS style)

I was not sure which prop so I got a few. I bought the airframe separate to the hardware and all up cost me about 2 pineapples ($100). Bargain.

Note: Coming from HK it is of course a clone. It is also known as the TechOne Mini Tempo 3D .

019 Diversity progress.

posted Jan 28, 2013, 10:14 PM by Marc G [ updated Feb 8, 2013, 5:25 AM ]

018 Introducing The Amp Hour.

posted Jan 18, 2013, 9:33 PM by Marc G [ updated Feb 8, 2013, 5:36 AM ]

If you have never heard of it. It is a radio show with two engineers talking about everything electronics. I like it. So far I have listened to the last 10 episodes and the first 15. I still have 100 more to listen to and new ones come each week.

Early episodes are just Chris and Dave chatting away about whatever they can think of. Lately they have been having some very interesting people on as guests. One that my visitors must listen to is when they have Chris Anderson creator of DIY Drones as a guest on the show. If you only listen to one episode then listen to this one:

The Amp Hour #105 -- Deambulatory Daedal Drones

Dave's EEVBlog originally got me inspired to start my youtube channel. Chris has not really inspired me to do anything yet. At least his voice is slightly less annoying.

Just kidding, listening to both of them has got me seriously thinking about open sourcing my diversity receiver prototype and refining it enough to try and sell it. Chris also runs Chip Report TV, I have only watched a little bit so far. Very niche and technical.

Anyway, The Amp Hour gets a big thumbs up from me. Have a listen. If you do not find it interesting, then you probably should not be here.

Disclaimer: The real reason I wrote this article it to get a mention on their show. :)

Chris: You might find Arduino on the KK2 interesting.

Dave: For your canyon copter: FrSky range testing with the 9X.

Cheers.

017 Mini Tricopter out of action, for now.

posted Jan 1, 2013, 7:31 PM by Marc G [ updated Feb 8, 2013, 5:25 AM ]

016 Successful FPV first steps on the Mini Tricopter.

posted Dec 25, 2012, 11:08 PM by Marc G [ updated Feb 8, 2013, 5:25 AM ]

My first FPV flight was with the flying wing. It was scary, fast and twitchy. At the mercy of the wind and prone to spinning in a stall it was not a pleasant way to learn. I had a very short go on the Bang Buck Quad and then on a tri-copter made from the same hardware. Again the flights were difficult I was too nervous about crashing these heavy beasts and smashing the FPV gear to bits.

So I built from scratch and I built light. Balsa wood and bare electronics. Anyway here is some very amateur filming of my first FPV flight on the Mini Tricopter, as you can see I was pretty pleased with the flight.

I also have a few more videos on the Mini Tricopter playlist.

Cheers.

015 Tungurahua Volcano explosion and eruption.

posted Dec 17, 2012, 7:52 AM by Marc G [ updated Feb 8, 2013, 5:25 AM ]

Somewhat bigger than a battery exploding. At 6am our local volcano produced a large explosion which shook the house, scared the shit out of me and sent the dogs barking mad. Two hours later ash started falling and then she started erupting in ernest, 24 hours later she is still going strong. Ash clouds fill the sky and there have been several pyroclastic flows.

This graph is from the Ecuadorian Institute of Seismology and Vulcanology. It is one of several such monitoring stations for Tungurahua and it is updated in real time. Their website is full of good information, a big thumbs up to the scientists there. All the red parts I can hear from my house which is 15km away. The nearest town (Banos de Agua Santa) is much closer to the volcano so spare a thought for everyone living there. For them they sweep up the ash and life goes on. I have to go to town to pay some bills and get supplies in case it gets worse. After that its a great reason to work on more articles indoors until the rain washes the ash away. I'd say I will have even more time up my sleeve as they say here "An eruption a day keeps the tourists away."

This is a photo I took December last year, it is a much smaller eruption than the one that is happening right now.

Tungurahua volcano eruption, explosion and pyroclastic flows.

Why post this here? Eventually I would like to fly a drone over Tungurahua. I still have a long way to go but I already have an FPV Raptor as an airframe and an Ardupilot Mega from DIY drones. The summit of Tungurahua is 16,000 feet ASL, and I figure I could start the flight from about half that altitude. Its a big task for a little plane and perhaps impossible but it will be fun trying.

014 Trustfire battery explosion.

posted Dec 15, 2012, 7:24 AM by Marc G [ updated Feb 8, 2013, 5:24 AM ]

Can we trust Trustfire batteries?

Remember these batteries? I used them in my Turnigy 9x battery upgrade. I managed to overcharge the so called "protected" cells. Looking at the revision history this happened late September. So about 2 months ago.

I left the dead cell on my shelf with the intention of doing a teardown at a later date. I never got the chance, the thing exploded.

These are all the bits after I cleaned up an collected them from all parts of the desk, shelf and floor.

Because my desk was such a mess I actually did not notice that anything had happened, I just thought that opossums had been running around above the ceiling as there was black dust over everything.

Then I realised what had happened.

After removing all the non dead battery stuff from the desk this is what was left. Luckily the laptop was elsewhere for the explosion.

Black ash everywhere.

You can see the outline of the tools.

This is over a metre from the source.

This pot got embedded in these pliers.

And my poor TX had a burning bit of battery land on it. This was taken after I scraped all the melted stuff away. Luckily it still works.

And this was the source of the explosion. Obviously there was a fire also, I was lucky my new office did not burn down.

For over two months this cell had just sat around, then one night with no provocation it exploded. Thinking back I must have heard it from the house, the dogs went nuts too. I just thought it was the usual backfiring car or fireworks which happens a lot here in Ecuador.

To be fair I was not using the recommended charger. In fact I just stuck it on a 12V 500mA source and relied on the protection circuitry.

I still have the other one from the pair that is now powering a small mp3 player. I will not be using that anymore as I don't want to blow my bollocks off. At a later date I will take it apart to see if it really does have protection circuitry inside. I am guessing not, as I searched hard for the circuitry in the debris. Perhaps it got burnt away, we will see..

Done, enjoy.