Thursday, April 17, 2014

Some Interesting 9xr/OpenTx History

Courtesy of Mike Blandford:

The original 9X, with er9x firmware, once it had the telemetry mods and the voice module I designed added, does all those things. OpenTx was forked from er9x some time ago, but many of the basic concepts are still the same. In particular, the mixer was originally designed by Thomas Husterer, who deserves far more credit than he generally receives. It was he who wrote the TH9X firmware with the mixer in. Erazz took TH9X and forked er9x, and later I added to er9x. 
Before the Taranis, there was also the Gruvin and SKY board upgrades for the 9X that provided a much easier upgrade method for the 9X to provide these extras. Having modified er9x for the SKY board (ARM processor) I was able to quickly write the low level drivers for the Taranis, much of which is still in the current firmware.
The Taranis and the firmware have just made this more accessible by being sold complete and ready. 
So please remember the history, and provide credit the originator "Thomas Husterer" for currently used concepts.
blogodex: History;

Sunday, April 13, 2014

The East Bay Taranis Switch Wrench!

 Over on the RCG Taranis thread there's been a couple of nice homemade switch wrench designs presented.  Here's our entry!

Not particularly fancy, just clip a large paperclip in half and trim to the appropriate size.  It doesn't take a lot of torque to tighten a switch pretty tightly.

blogodex = {"idx" : "Taranis Wrench"}

Sunday, April 6, 2014

LiPo Battery Charging and Storage

The Charming Mrs. EastBay RC puts up with a lot in the service of her husband's various hobbies, but one place where I'm pretty sure she would draw the line is burning down EastBay RC's international headquarters.  I've experienced first hand the rather unpleasant experience of having a LiPo battery short out and burst into flames, so I'm a stickler for careful battery charging, handling, and storage.
 Here's my main charging station.  That's a HobbyKing 4 port charger powered by an old PC power supply.  The charging bunker consists of a standard sized concrete block sandwiched between two flat blocks.  I painted everything white to look a little better and to keep dust, etc from coming off the concrete.  I've notched the block so that battery leads can fit in with the top closed.  There's a smoke detector on top, and a fire extinguisher next to my workbench.
 Here's my battery storage bunker.  It's a fireproof safe that I salvaged out of recycling.  It weighs a ton.  The unit was open with the door bolts set in the locked position.  I tried (unsuccessfully) to figure out how to set a new combination, but it works perfectly as a battery storage bunker.  The door is heavy, so I just need to be careful not to drop it on my fingers.
Here's a view showing some batteries.  One day when I have some time to kill I'll put some shelves in to make the storage a bit more tidy, but for now I'm really pleased with it.
Prior, I stored everything in an old ammo box, which was a bit more restrictive in space.  The Internet seems to think that it would be fine for containing the open flame of a burning LiPo.  Prior to that, I kept everything stored in a concrete block similar to my charging bunker.  I've also got some LiPo bags for use on the go.

Bottom line:

  • Take LiPo charging and storage safety issues seriously.  Watch some youtube videos on "lipo battery fire" to ensure that you do.
  • Get something to put your batteries in while charging.  I think a LiPo is actually a good solution, but it's a bit more convenient to have a larger bunker if you've got the space.
  • Always stick around while your batteries are charging.  I typically charge while I'm at my workbench so it's not a problem for me.
  • Keep a fire extinguisher nearby.  This applies to your workshop or hobby table as well.
  • Be careful, but not anxious.  I've never (thank God) been in a car accident, but I still wear a safety belt when I drive.  Same here... it's a bit overkill until the one time it isn't!
  • If this save you from burning down your place and getting in big trouble with the family, you owe me a verrrry nice dinner!
update: here's my bag of sand that I was using to cover the hole in the concrete block before I switched to the flat concrete block.  The reasons I switched were:
  • I wanted to move the charging station from the garage to my workshop so it would be a bit easier to attend to.
  • I was in deathly fear every time I handled the bag, afraid it would split open and I would be vacuuming sand for hours.
  • After watching a couple of youtube videos I think the concrete topper will contain any open flames.

blogodex = {"toc":"Lipo Batteries","index":["Safety","Batteries"]}

Thursday, April 3, 2014

On The Waterfront

I went with some coworkers on a field trip to Autodesk's amazing Pier 9 workshop.  It's the same space where Instructibles has their office.  There's a great overview of the space here, but I took a few pictures of things that caught my eye to post here.  The Autodesk people were great hosts and really sharp people.
As I recall, they have six or eight main areas... woodworking, kitchen, metalworking, milling and cutting, whatever it is that 3D printing and laser cutting is called, electronics, and sewing.  There's a mold-making room as well.  On this shelf are a few of their interesting projects.
Here are some records that were made by laser etching maple disks.  I missed the name of the person that made them, but she had some 3D printed records as well.  The key insight was taking an audio file, pulling the waveform, and mapping that onto the disk.  Neat!
Norm Abram would approve.  There's a bin of safety glasses at each of the doors.
Here's the water cutter.  It can cut through 4 inches of steel plate.  Current software for driving these kinds of devices is not particularly sophisticated.  You could give a toolpath that would cut the machine in half and it would cheerfully execute it.
A 5 axis CNC milling machine.  I'm not sure if the picture shows the scale very well.  That's the second floor walkway at the top left.
Here's their library of milling bits.  The big machines are a bit out of my brain space, but having bought router and shaper bits all I could think of was "wow that's a lot of money in that drawer!"  There's a machine that heats the bit holders so that when the bits are put into place the metal contracts and holds everything tight.

The control panel for one of the milling machines.  They're working on networking all the machines together.  Traditionally there hasn't been a lot done in that space, since a machine might be bought to manufacture a certain part, and will run the same program for years on end.
The woodworking shop.  Smells good and splendidly dust free!
As you are trained and checked out on each machine you go into the database.  Each machine has a keycard reader for access.
In the wood shop. Background, that cabinet is filled with fasteners of all shapes and sized.  Foreground, some amazingly talented and cool coworkers.
The metal shop.
Old fashioned 2D printing!
My lust burns bright, with the intensity of a 400 watt laser beam!
They had a shelf of interesting projects to show visitors.
This was 3D printed from a topographical map.
Some 3D printed models.
Whatever might go wrong, they'll know about it right away!
3D printer.
The second floor garage door.  Below is the driveway into the Pier 9 building.
As it was explained to us, these 3D printers are resin based.  The laser light cures the liquid resin.  I had hoped to see how the finished model was removed and cleaned (is it dripping with liquid resin?) but wasn't able to.
These were some of the things on the demo shelves.
This planetary gear was 3D printed in one piece. Check out the video below to see how smooth it is.
This tank chain was also printed in one piece.  I'm not sure about how the treads were attached.  It would be cool if they were printed in place as well. I made a quick video of this as well.
Here's the result of a project done in cooperation with UC Davis.  It's a print based on an MRI scan or somesuch of a horse tendon.
Here's the view from their sewing room.

Monday, March 31, 2014

Notes: Welcome to Taranis, Part 7: Elevon Mixing

These are notes to accompany the Welcome To Taranis series.  Follow the link to see the videos and other notes.

Part 7: Elevon Mixing

Elevon Information Theory

Motion Rules
  • elevator back: elevons up
  • elevator forward: elevons down
  • aileron left: left elevon up, right elevon down
  • aileron right: right elevon up, left elevon down
  • Mix the elevator stick on both channels.
    The value will be either 50% or -50%, depending on how your servos are set up.
    If the control surfaces move in the wrong direction, swap the sign.
  • Mix the aileron stick on both channels.
    The multiplex parameter will be "add", and the values will also be 50% or -50%.
    Proper motion:  when the stick moves left, the left control surface should raise and the right control surface should lower.  Vice versa for moving the stick right.
Example Mix

Ch 2  Ele    50%
  +=  Ail   -50%
Ch 3  Ele   -50%
  +=  Ail   -50%

blogodex = {"toc":"Welcome to Taranis","index":"Taranis"}

Notes: Welcome to Taranis, Part 6: Setting Up a Four Channel Plane

These are notes to accompany the Welcome To Taranis series.  Follow the link to see the videos and other notes.

Part 6: Setting Up a Four Channel Plane

Safety Note

  • Be sure and remove or disable your prop when mixing. 

Example Setup
  • Channel 1: Aileron
  • Channel 2: Elevator
  • Channel 3: Throttle
  • Channel 4: Rudder
  • Channel 5: Gear
Set up each channel 1-5
  • As per the mix instructions in part 5, mix each stick to channels 1, 2, 3, and 4.
  • Reverse channels as necessary using Servos menu.
  • Likewise, mix one of the switches to channel 5 for the Gear.

blogodex = {"toc":"Welcome to Taranis","index":"Taranis"}

Notes: Welcome to Taranis, Part 5: Dual Rates and Expo

These are notes to accompany the Welcome To Taranis series.  Follow the link to see the videos and other notes.

Part 5: Dual Rates and Expo

Model menu 5

Dual Rates
  • Select a switch, change the weight.
  • Use "add after" to add a second weight.
  • Select a second switch (or same switch, different position), and select a different weight.
  • Edit a stick, change the Exponential value.
  • Normally, positive expo value is what you want (softens midpoint).
  • Can be combined with dual rate settings as per above.

blogodex = {"toc":"Welcome to Taranis","index":"Taranis"}

Notes: Welcome to Taranis, Part 4: Mixing, The Heart of Taranis

These are notes to accompany the Welcome To Taranis series.  Follow the link to see the videos and other notes.

Part 4: Mixing the Heart of Taranis

Mixer menu is model screen 6.

Simplest case

  • map a source to an output.
  • e.g. map the rudder stick to channel 4.


  • "scales" the input
  • negative weight acts as reverse.
  • often better to use "reverse" function on stick menu

Switch mixing

  • specify a switch as an input
  • top, middle, down maps to 100%, 0%, -100%

blogodex = {"toc":"Welcome to Taranis","index":"Taranis"}

Sunday, March 30, 2014

Notes: Welcome to Taranis, Part 3: Binding a D Series Receiver

These are notes to accompany the Welcome To Taranis series.  Follow the link to see the videos and other notes.

Part 3: Binding a D Series Receiver

  • Note polarity on receiver.
  • remove or disable props.
  • on Rx, power on while pressing failsafe/bind button
  • on Tx, go to model setup screen
  • select mode D8, channel range CH1-8
  • select bind, hear beep
  • disconnect and reconnect power on Rx
  • Tx/Rx bound, controls should be operational

blogodex = {"toc":"Welcome to Taranis","index":"Taranis"}

Notes: Welcome to Taranis, Part 2: Binding an X Series Receiver

These are notes to accompany the Welcome To Taranis series.  Follow the link to see the videos and other notes.

Part 2: Binding an X Series Receiver
  • note polarity on receiver.
  • remove or disable props.
  • on Rx, power on while pressing failsafe/bind button
  • on Tx, go to model setup screen
  • select mode D16, channel range CH1-8
  • select bind
  • disconnect and reconnect power on Rx
  • Tx/Rx bound, controls should be operational

blogodex = {"toc":"Welcome to Taranis","index":"Taranis"}

Notes: Welcome to Taranis, Part 1: Out of the Box

These are notes to accompany the Welcome To Taranis series.  Follow the link to see the videos and other notes.

Part 1: Out of the Box

Check Battery
  • connector in place
  • keyed connector in left side
Charge by plugging in wall wart adapter
  • older models will show solid charging light
  • newer models will blink then go solid
  • charger will shut off automatically when battery fully charged
Turning on
  • Throttle warning will appear if your throttle is not down
  • Switch warning will appear if any switches are not off
  • fast click for model selection menu
  • slow click for radio setup menu
Stick Calibration
  • radio setup menu screen 7
  • center everything and press enter
  • move everything full range of motion and press enter

blogodex = {"toc":"Welcome to Taranis","index":"Taranis"}

Wednesday, March 12, 2014

Welcome to Taranis! Video Series Guide

Here's a series of videos I did in conjunction with Aloft Hobbies an FrSky RC.  It's is designed to get you up and running on Taranis as quickly as possible.

I've got some more in the works.  What topics would you like to see?  Where have I got something wrong?  Let me know what you think!

The screen looks better (a lot!) in HD.

Series Contents

    The series playlist is here: Play All.

    0.  Introduction. (video) (notes)
    1. Out of the box setup. (video) (notes)
    2. Binding an X series receiver. (video) (notes)
    3. Binding a D series receiver. (video) (notes)
    4. Mixing, the heart of Taranis. (video) (notes)
    5. Dual Rates and Expo. (video) (notes)
    6. Setting up a 4 channel plane. (video) (notes)
    7. Elevon mixing. (video) (notes)
    8a. Basic Telemetry. (video) (notes)
    8b. Audio Telemetry Alerts. (video) (notes)
    9. Basic Speech. (video) (notes)

This video series is a coproduction of FrSky RC, Aloft Hobbies, and EastBay RC.

I'll fill in some links to some supporting text material.

CME Meeting Minutes, March 11, 2014


Tuesday, March 11, 2014

CALL TO ORDER:  7:30 pm


    Monthly meeting, Second Tuesday, 7:30 at Concord Airport Terminal.

    Friday Fun Fly, Third Friday, 7:00 - 9:00 pm.
    Gym at the Church of the Nazarene, 1650 Ashby Dr., Concord

    This month's Fun Fly is on Friday, March 21.

Thursday, March 6, 2014

EastBay RC at the Great Wall of Oakland!

Stop by Friday, March 7, 7pm - 11pm!  They'll be showing two of our videos as part of the Pixar "behind  the scenes" show.

What's the Great Wall of Oakland?
"Every first Friday during OAKLAND ART MURMUR, the Great Wall of Oakland, a 100'x100' projection installation, illuminates the Uptown District with cutting-edge motion art from around the world. Thousands of Bay Area art fans descend upon the area to check out this one-of-a-kind site."

And what's this event?
"For the 3rd year in a row, The Great Wall will present a curated screening of the personal works of Pixar Animation Studio employees on the 100’x100’ urban canvas. This very unique glimpse into the creative minds of our talented Emeryville neighbors is the only public screening of it’s kind, giving Bay Area residents a rare opportunity to view the short films that Pixar employees create in their spare time when they are not working on major blockbusters.

Friday, February 28, 2014

East Bay Guide to Understanding PID Loops, Part 2

Building on the intuitive model presented in part 1, we take a look at the mathematical model and write a PID control loop based on that model.  Hang in there if you're unfamiliar with the math... it turns out to be pretty straight-forward code in the end!

Like part 1, this is a first take.  I was going to make a second take, but I discovered I had scribbled all over my only nice-looking copy of the PID math.  Your comments are welcome!

The printed formula is from wikipedia.  I tried doing this Khan Academy style with a tablet... wow that's hard to write with, that man is a genius if for no other reason being able to use one of those things!

blogodex = {"toc":"East Bay Guide to Understanding PID Loops"}

Things to Try: OSW the OneSheetWing

The ever-awesome Springer made the OSW a while back.

"It's not like we don't have a plethora of wings on the scratchbuilt foamies forum, but, hey, I'm working my way through all the genres in this onesheet madness. For those who may not have seen the OSG or OSB thread, the premise is to make a plane that uses as much of a 20"x30" sheet of dollar store foamboard as possible. So, Here she is the OneSheetWing"

The fuse is just a penthouse to hold the firewall/motor mount and gear out of sight. The pattern on plans is cut out, then the inside v cut and then grooved with top of xacto knife to get it to fold. Glue and tape together. first picture is V1 fuse (was gonna do one on top and one on bottom, but stopped at only the top), but V2 goes together the same.

blogodex = {"index":["Things to Try","OSW","One Sheet Wing"]}