Sunday
Jun022019

Custom lighting for PPG.

I started to design a custom lighting driver to drive and control 255LEDs + a LED strobe on my Paramotor.  Here is a breif video of them in action.

The design consists of 3 major components.  The battery,  The driver box and the keypad control box.  The way i currently have it programmed is as follows.  Numbers 0-9 switch different patterns.  The * key acts as a "shift"  so * followed by a number gives me 10 additional patterns.  If I outgrow this, I can rethink this, but for now it seems to work ok.  The # key toggles the strobe on or off.  My design uses 2 ATMEGA328 microprocessors.  The idea is, 1 processor is dedicated to running the strobe, so the strobes timing is independant of anything going on with the ring lights.  The second processor polls the keypad over i2c and runs the ring lights.  Additionally, processor 2 toggles a pin high or low which acts as a signal that processor 1 is listening for to determine if the strobe should be on or off. 

Going with 2 separate processors significantly reduces the processing load as opposed to trying to do it on 1 chip.  The keypad is a nifty thing that sparkfun came up with called the "Quiic Keypad",  this is nice because it talks over i2C and handles all the keypad matrixing/polling, further reducing processor load of my main processors.

There was 1 issue with using The sparkfun keypad.  It operates at a 3.3V logic level and my stuff operates at 5V.  So I threw in a local VREG and a logic level converter to handle this descrepancy.  Finally I connectorized everything so that I can quick disconnect any given component if I need to.  The connectors are all keyed and different, so it's impossible to accidentally connect the wrong component to any given connector.

Finally, I designed in Solidworks and 3D printed custom enclosures for the driver and keypad boxes.

Here are a few photos of the build...

 

Inside the driver box.  Custom PCB that I designed and had made.  Also using a Castle Creation off the shelf 5V/10A buck converter to drive the ring LEDs.

Cad view of the PCB...

 

 

 

My CAD design for the keypad's enclosure...

 

The finished modular keypad...

 

Driverbox and Battery mounted on my frame...

 

Keypad mounted to my harness so that I can reach it in flight...

 

Testing out the lights on the ground...

Friday
Nov232018

I bought a wing!

Just a quick update.  I bought a wing!  Found a good deal from Germany on the Facebook PPG buy/sell/trade group.  Only 3 flights on it.  Very happy with this purchase, it is brand new condition, everything is crisp and even still smells new :).  I love the color scheme as well!

I still need a motor to complete the ensemble, but I can at least get out and practice kiting with this.  Hope to pick up a motor come spring time or so.

 

 

Saturday
Oct062018

Powered Paragliding.

Sorry for the long haiatus.  It's been a busy year and I haven't had much time to work on projects.  The few projects I have been working on, I haven't done a good job at documenting.  This site is probably turning into a very sporatic life blog more so than a dedicated project site.  That being said, I do hope to submit future projects (time permitting).  I thought I would post something I have recently been doing.

I very recently got back from a trip to Midwest Powered Paragliding in Franklin, Indiana.  I spent about 9 days learning how to fly Powered Paragliders (PPG).  While I was out there, I got 36 flights in and earned my "PPG2" rating.   I went from knowing very little, to being talked through my first flights to now being fit to do this on my own without instruction.  This was an exciting adventure that I can't wait to do more of.

Here are a few videos and photos from this adventure...  The best way to keep up with my goings on is via my Youtube channel which I do post to more frequently :)

 

 

Sunday
Jul232017

Business Card, RevB

I am working on RevB of the dice, PCB business cards.  Maybe you are visiting this site after having been given one of these.

I built up a bulk programming rig using a TQFP Socket and a USBTINY programmer. This is for bulk programming of REV B of my "Business Cards". I was able to burn these 19 chips in less than 5minutes. Longest part was getting the IC's into and out of the socket. Wrote a batch file that would quickly run the AVRDUDE commands needed to burn the fuses and write the HEX to flash memory and verify.


Some of you may have one of the original versions of this that I made a few years ago and handed out. Below pictured is the RevB prototype. I made a mistake on the prototype and had to cut a trace and reroute a wire. This will be corrected in the production version. Production version will use blue, not purple solder mask.

For the geeks, Here are the list of changes between RevA and RevB...
* I made the whole thing thinner by eliminating the battery clip and recessing the battery into the PCB flush.
* Eliminated a bunch of components, namely the pushbutton (was able to make the battery clip also function as a switch. * * Eliminated the current limiting resistors on the LEDS, I instead now pulse modulate the LEDS in software to reduce apparent power to them.
* Switch from the ATMEGA328 to the less expensive ATMEGA48
* Eliminated the clock crystal and instead use the internal oscillator on the ATMEGA48
* Eliminated nearly all vias and improved overall PCB routing. Intentionally went with an organic "curvy" PCB trace routing for aesthetics instead of the more traditional 45degree routing.

 

Thursday
Oct082015

Quest for the 100MPH Plane

I feel the need,  the need for speed.  I am currently working on a 100+ MPH HobbyKing radjet.  I am not quite there yet,  but feel I am well on the way.  Here is the current state of things.  Below is a video from FPV Fest where I clocked it at about 75MPH..

 

How am I going to break 100MPH?  Bigger motors and bigger batteries of course!

 

First off,  some data (click the chart to open a larger version)...

 The data in orange is what I was running in the video you just watched,  the data in yellow is what I plan on running.  Notice nearly twice the thrust! 

 

Here is a better comparison of the two options...

Notice a few things...

  • nearly 3 times the amp draw
  • the prop speed is up to 164MPH from 97MPH
  • applying my actual losses I estimate the plane will go 125MPH

 of course, I figure that losses probably are logrithmic not linear, so the diminishing returns from actual losses due to more weight might be a bit more,  however I still feel pretty confident I can break 100.  The batteries are going to take some punishment.  I am going to need to run a 50C 1600MAH with an 80AMP ESC.  Stay Tuned!