ER9x -> OpenTX

  I've been running and flying with ER9X for some time.  It seemed to mostly work but it also seemed to push buttons on its own occasionally.  It even managed to enable a different model on me more than once.  My Iris was about a foot off the ground doing circles and the throttle was still working so I just ditched it.  It may have all been the cold or bad contacts.  I had looked at OpenTX as it seems to be "the thing" right now.  The instructions weren't very clear for non Taranis TX models until I played around a bit.
  First, just use the companion app...  period.  I'm currently running 2.0.15.  The MacOS build is missing so I used my Linux box.  By default it seems to boot in Taranis mode but don't worry.  Click through the splash screen.  Find the preferences (varies by OS).  Make sure to select the radio type and pick OpenTX for 9x board.  If you have the same hardware config the build options should include SP22 (Smartiparts backlight - this enabled the reverse mode so that on really is on) and Telemetrez (not frsky) to get the telemetry enabled properly.

  Then exit and it will prompt to download the latest and greatest firmware with the config you just selected.  Backup everything with a few clicks and then flash the new firmware.  Now rebuild your model/radio configuration.  Flash the firmware (beware the avrdude 6 computability issues, I just use 5).  My battery voltage seemed to be incorrectly calibrated after the update, I'm going to just plug it into my charger, take a reading and then adjust the calibration.  OpenTX seems like its more stable but I haven't had as many flights with it yet.  I need to make sure RTL is setup to enable on signal loss so I can at least get things back by fully shutting down the TX.  Its very scary not 100% trusting your TX.  This is just what I did.  I make no warranty.  I hope this helps people, but you are probably flying an expensive and dangerous vehicle.  Please test fly in safe situations.

Iris Telemetry (RX)

Today I completed my original IRIS telemetry setup on the receiver side (TX is here).  This completes the telemetry setup and it is at least mostly working.  I tried to buy the right parts to get plug in the RX but I failed to get the right connector for the receiver.  I'm Annoyed that 3DR didn't ship the telemetry cable with the FrSky RX given that FrSky seems to ship it by default.  Anyhow...
Parts List:
 FUL-1 (level shifter and inverter I believe)
 Any 6pin df16 cable
 Any 4pin df16 cable
 Some 4 pin .1" pitch cable
 Pre-assembled 4pin molex picoblade cable (I haven't found this yet)

This is the setup I was working from and really contains everything you need except finding some of the parts and that the serial port speed on the Pixhawk->FrSky telemetry port seems to be 9600 baud which needs to be configured in APM Planner, its just above the setting for telemetry port 2's output protocol mentioned in the above link.  I just cut the ends of the cables off above and soldered them up to make the cables from the page above.
  As mentioned I never found the FrSky RX plug which sucked (3DR clearly ships this cable and converter with the Iris+, wish they just put it on their website).  I gave up and just soldered to the pins on the back of the RX, I'll fix this when I find the connector.

An important note that I screwed up the color scheme here compared to what everyone else seems to to.  Yellow and Brown are usually reversed of what I did.  The connection is not great.  In the end it really needs the correct plug.  The cable is bent sharply when installed in place which pulled off the first solder job (I was being paranoid about heat).  I don't recommend this.

Here's the final setup.  The important part is the FUL-1 connected between Pixhawk Telemetry 2 and the FrSky RX.  

  Telemetry doesn't seen perfect.  I'm not sure how much of this is due to the transmitter firmware (I'm currently on er9x-frsky, I've been meeting to try opentx), maybe some of my installation, possibly the pixhawk not implementing exactly the FrSky hub protocol or possibly even radio interference.

  * Some values occasionally are corrupt, including random characters in numeric fields

  * Trying to reconfigure the customer telemetry fields while the radio is receiving telemetry data doesn't work

  * The backlight sometimes flickers when telemetry is active

  I'll report back when I have time to fly it.

Telemetry Antenna Mount

One of the other things missing from the Iris+ upgrade kit was the new Antenna mounting for the Telemetry radio.  This does a *much* better job of protecting the antenna and radio.  One of my most common issues when I first started flying was backflips while landing.  This would hit the antenna (which could only stick up).  Not only that, but the antenna was screwed directly onto the circuit board.  I had already managed to rip the antenna connector traces off of the board.  I replaced the 3DR radio with a cheap clone sold on Amazon but I wanted something better.  During my upgrade to the Iris+ motors and such I figured I would try and do this myself.  I found this cable on Amazon which has terrible shipping options but 3DR was also taking a while to ship the Iris+ kits so I went for it.  They both arrived within a day or two of each other.  Note that all of the specifics of that cable are important and I didn't find anything else on Amazon.

That is the final install in the top of the Iris.  The telemetry module is velcro'd on like the RX on the other side.  That also is *not* the 3DR module due to my original accident.

I mounted the Antenna as high as possible so it could point down and not touch even with the short legs on.  It basically dots the second 'i'.  Its important to also check the clearance by the legs as you are going and not put it *too* close to the top so you can't get it in.

Another angle for completeness.  You can also see that I started labeling the channel numbers on my telemetry radios for easy pairing.

Vibration

I've been trying to figure out where some vibration as coming from.  I had thought the gimble might have been damaged in the previous incident or the new mount might be making contact.  I certainly improved things when I cut back the gimble but it was clear the whole vehicle was vibrating in certain conditions.  Then I spotted this on two props.

The tip curves up and is bent out of shape.  I suspect this happened in the same crash as the mount breakage.  The old Iris props would have simply snapped, these seem to bend a lot but not break.  The bad thing is this can cause a lot of vibration and you might not know it.  I'm also on the hunt for a better source of props than 3DR.  I don't know if the mount is standard though.

Replacement Tarot Mount

I added the Tarot gimble to my Iris very shortly after I got it.  It really does make a world of difference.  Recently however I had a mishap with a full auto flight where the speed probably dropped the barometric pressure just enough to fly low enough to hit the ground - Controlled Flight Into Terrain is the term I believe.  I wanted the gimble for more flights that weekend so I trolled thingiverse and found this.  It works like a charm but needed a bit of a trim to fit well with the original top plate which was still in one piece.

Iris Nexus 7 Mount

I had been flying my Iris for a bit when I decided it was really time to start mounting an Android device somehow.  I scoured over Thingiverse and found this.  Having a DX6i I checked the handle and they were the same.  I had to get the actual Nexus 7 piece printed by a friend because it was too big for my print bed.
  The mount is fantastic for keeping an eye on things and even doing some follow-me or guided modes.  I have noticed a few things.  First I often stick my phone in AP mode in my pocket so I can get maps on my Nexus 7 when I'm out in the field.  This works great except the Wifi is 2.4ghz.  I have noticed that I loose all Wifi on the tablet if the TX antenna gets too close to the back of the tablet.  I'm also fairly certain it doesn't do wonders for range.  I try to cache my maps now and keep Wifi off.  So far I've just taped the telemetry radio to the back of the mount.  It works okay, but the telemetry radio is the weakest link on the Iris so I sometimes end up holding things at awkward angles to keep signal strength up.
  The only think I don't like is that the remote no longer fits well in the padded case without a ton of disasembly.

Iris Telemetry (TX)

I upgraded my Iris with the Iris+ upgrade kit.  I was a bit annoyed that 3dr didn't make anything available to get the telemetry setup working.  Here's what I'm trying to do to get it working.

Radio Side:

• Smartieparts 9x Programmer
• Smartieparts 9x Telemetry
• HobbyKing LED backlight

I got the Smartieparts on a nice holiday sale.  I wish they were a bit cheaper for this project but they are well made, come with *everything* you need and it makes the whole project far less daunting for the average person.  I also had a quick interaction with Steven and he was awesome.  I don't need to add anything to his installation instructions, I followed them exactly.  I did the 1/8 inch hole in the TX and popped the pins out of the holder. 

I didn't have to get the backlight, but it just made sense to do it while the TX was apart.  It makes a huge difference in the readability of this TX.  I just cut off the plug, soldered and electrical taped the backlight leads to the included Smartieparts plug.

It ends up quite a tight fit in the TX.  I had to fiddle around for a bit to get it all in there.

Turns out the TX assembly was much easier than the work once the case was closed.  I'm currently still using ER9X but I heard from a poll on the Iris Facebook group that 3DRobotics has changed over to opentx for Iris+.  I used Eepe to load my firmware.  You'll also need Avrdude which is called to do the actual flashing.  I ran into two problems I hope I can help people around here.  First I had a bad USB cable.  I didn't think this was a thing that happened and I pulled the whole thing apart an extra time because of this.  If your computer doesn't recognize your device try swapping cables.  In Linux dmesg I saw nothing, on Mac dmesg I got 

Jun 21 21:04:49 MDD kernel[0]: USBF: 3305.491 [0x2a3e300] The IOUSBFamily is having trouble enumerating a USB device that has been plugged in. It will keep retrying. (Port 4 of hub @ location: 0x18200000)

Once that was resolved I first saved off my old Iris Firmware and EEPROM settings.  Unfortunately my configuration wasn't entirely factory because I had enabled some other configuration which I have yet to document.  My first load reported a checksum failure while reading back the data.  The remote failed to boot at this point.  I then tried flashing back to the original and got a very similar error (location 0x0100 fails to verify).  At this point I had to remain calm and not panic.  After a bit of research I found that Avrdude has a bug in version 6.0.x which causes it to write the first block twice or something like that.  Obviously this won't work.  6.0.x is the current Ubuntu 14.04 and Homebrew version so you will likely have to get it from somewhere else.  I sadly ignored my better judgement and used the .deb from this forum.  This solved the issues and I now have my TX running ER9X-FRSKY.  There is no real release process for ER9X so YMMV with that link.  I don't recommend ER9X for this, please see more recent posts on OpenTX.
  This also meant that I got to reconfigure my Model.  I had dumped the EEPROM so I think I could have migrated them but I figured learning a bit about how to set things up was not bad.  The Mixer ro get the multi-position switch setup was especially fun.  I found the manual only got me so far.  I found this tutorial also helpful.  The specific thing I missed was that I should be using replace rather than add for the mutli-switch madness.
  I don't yet have the RX side of the telemetry setup so I can't see much yet.  I'm 99.9% sure the signal strength meters come back trough the telemetry so here it is.  Oh, and the backlight looks nice too.