SK-450 frame with PixHawk PixRacer build continued Spring-2019

I recently found my un-finished SK-450. It was to be my first Pixhawk-class aircraft. I think I will work on it for a while, and hopefully get it more flight-worthy .

Since it's the original PixRacer-clone model in the metal-box/case, I decided to just mount it with four 11mm-square pieces of black HobbyKing Zeal-clone material. I then tied it down with a thin nylon-wire-tie. I don't think a "dental-floss tie-down" is quite enough after all. Like the compass, it would be really bad if the FC became detached in flight somehow.

The on-board RC receiver (a FrSky-X8R) is mounted up-front (upside-down, so that top of X8R still ends-up being accessible) .
If you Bind manually, you want:
Mode-4 (D16) FrSky-XJT = CH1-CH16 with Telemetry. FailSafe-Mode is No-Pulses.

On the Taranis, you can setup a new model for the PixRacer-450.
Actually, I just duplicated an APM ArduCopter model (the Nova-360) , and then changed the name and Receiver Number. I noticed I did not even need to re-Bind. You know they are working (actively bound) when RSSI appears on Taranis. Also, the LED on the x8r will now be lit green.

In May-2019, I'm using the current Mission Planner (for Windows) v1.3.66 . I'm using a standard Micro-USB cable.

Upgraded the PixRacer's firmware from ArduCopter v3.5.4 to ArduCopter v3.6.9 (Quad with ChibiOS). Reboot the PixRacer-FC.

• Click Connect. 
• Reset Parameters with Reset to Defaults button. It will reset to v3.6.9 Defaults. Let it Reboot.
• Save initial default v3.6.9 params to file . Start building-up your best params from here.
• If not already Disconnected in MP, do so now.
• Shut-Down MP, disconnect cable, and power cycle aircraft.

On next power-up, ESC might be beeping.  Seems to indicate that ESCs aren't getting a signal because FC can detect that radio is not calibrated yet (getting that message in MP-HUD). Looks like the constant ESC beeping happens with ArduCopter v3.1.x (or higher) and certain versions of ESCs. And, of course, what the APM-FC considers an un-calibrated RC radio.

• Reconnect USB cable, start MP, and click Connect.
• In MP, set your main top-6 or so Flight Modes and Write/Save them
  1. Stabilize
  2. Loiter
  3. Alt-Hold
  4. Drift
  5. Land
  6. Auto
  ... and in Extended Tuning, CH7=SuperSimple and CH8=RTL (each of which I also have on dedicated Taranis buttons).
   
• In MP, calibrate the RC Radio, 
• The sticks obviously, but since the radio is already programmed, step thru all the pre-programmed Taranis Flight-Modes on the switches. All channels should move on MP screen (except CH6 which is not assigned to anything on Taranis).
• Remember that any problems at this point (like only some switches not responding) might be due to incorrect programming on the Taranis radio itself.
• Write params, click Disconnect and power-cycle (reboot) FC.
• If ESCs were beeping before, they should stop now (now that the radio is calibrated).
• Verify or Set Frame Type to X-Y6A (a X-4 quad-config)
• Recall that you have the PixRacer FC mounted in a normal/forward orientation.
• Compass is Forced-External (which also disables any Auto-Detection). Verify proper Compass Yaw-degrees hardware-config settings. Just using one the single external compass for now.
• I would say these are the minimum parameters you want to set or verify before calibrating:

AHRS_ORIENTATION,0
COMPASS_AUTODEC,1

COMPASS_EXTERNAL,2 

COMPASS_ORIENT,0 

COMPASS_PRIMARY,0
COMPASS_USE,1
COMPASS_USE2,0
COMPASS_USE3,0

FRAME_CLASS,1
FRAME_TYPE,1

Mandatory Hardware Devices - Click Connect and calibrate the rest of the mandatory hardware devices. The PixRacer seems to like being rebooted (and/or power-cycled) after each major component is setup and/or calibrated. Save your work and params files as you go.

If all is going OK with your Micro-USB-cable connection, you should be good to try connecting by WiFi instead. Its your choice.
- WiFi connection notes. Connect to copter's WiFi in Windows first. Use UDP in MissionPlanner .

• Accelerometer calibration. 
• Click the button to do the quick Accel calib (just leave level) and then reboot the PixRacer flight-controller (FC).
• After reconnecting, click the other button to do the longer (multi-step) 3D-Accel calibs. Reboot FC again when finished. 
• Follow directions. I find it easier to prop-up against a door because it must be keep still and perpendicular at each step. Use Enter/Return to go to next step.
• It should say Successful at end. 
• It might show the 6 calibration parameters it just created. IIRC, they should all be close-to or between -1.00 and +2.00. I think it might Write them to the FC at the Successful end.
• You can also see them as INS_??????? in params list.
• Return to Full Parameters List and Write them (just in case). You might need to Connect first. Finally, I Save as a File since we made it this far. 
• Compass Calibration
• Due to initial problems getting more than one compass activated and calibrated (with good Offsets) ... I'm just using the one main external compass (up in the GPS/Compass-Combo module) for now. This should also help with compass "variance errors".
• Calibration is pretty self-explanatory. Just start it and then slowly rotate the multi-rotor aircraft on each of its 3 main axis (likely a couple of times each). If done properly, it should progress and complete in good time. 
• It would not hurt to do this outside (like at least the back-yard). Not only would this eliminate any possible building-structure interference, 
• but also ... you can do it while Auto-Declination and GPS are active. 
• Note that after it has been done successfully, it SHOULD NOT need to be done again, any time soon. 

Optional Hardware Devices - Click Connect and calibrate any optionally-installed hardware devices. The PixRacer seems to like being rebooted (and/or power-cycled) after each major component is setup and/or calibrated. Save your work and params files as you go.

Battery Monitor or Power Module (standard APM-style PM)
- This is with a Turnigy 11.1v 2700mah 3s 20-30c LiPo battery
Monitor: 4: Analog Voltage & Current               Battery Capacity: 2700
Sensor 0:Other
APM Ver: 4:The Cube or Pixhawk
Power Module Calibration
1. Measured Battery Voltage: 11.6v (measure and enter yours here)
3. Voltage Divider: 10.82
6.  Amperes Per Volt: 19.1
For this PixRacer Flight Controller, my relevant parameters were:
BATT_MONITOR,4
BATT_CURR_PIN,3
BATT_VOLT_PIN,2

Reboot, and it should be working and now appearing in HUD.

Also, verify or change these core parameters     
(this first set should also be Pixhawk defaults):

ANGLE_MAX,4500
GPS_HDOP_GOOD,140
LAND_SPEED,50
LOG_BITMASK,176125       (Most logs, including IMU for vibrations )

RTL_ALT,2500
FS_GCS_ENABLE,0
FS_THR_ENABLE,1                (Very important)
FS_THR_VALUE,950              (Adjust for your calibrated radio throttle)

Also DONE :
- Install FAA ID-Tag sticker

ToDo:
- Calibrate ESCs (a good time, since new FC in new aircraft).
- More Arming and motor-run tests.
-     -    Already noticed GPS-Module working really well in shielded areas.
- Calibrate compass again, outside this time.
- Test Fail-Safes and RTL
- Setup Taranis "Flight Time" telemetry Page for this model
- Install props (mark type and direction)
- Tethered flight test.
- Maiden flight
-     -     Stabilize (manual mode) and hopefully some GPS-Modes testing as well.

Taranis OpenTX v2.2.1 Flight-Modes and Sound Profiles

Here are some setup notes for my Taranis (running OpenTX v2.2.1), about Taranis audio and setting-up sounds. Remember that if you switch computers and you start having USB detection and communication problems ... try a different (higher quality) Mini-USB cable.
OK, so let's start with this tip:

I setup the S1 (left) potentiometer to be the Taranis' full-time volume control. The other command is for resetting the Timer to zero. These are Global Functions (affects all models) .

A while back I assigned sounds to my Flight Modes (via Special_Functions and Play_Track) .

However when I am using an Android GCS (like Tower/Mission-Maker) ... their nice verbose announcements include Flight-Mode as well. Having them both announce the Flight-Mode seems redundant and un-professional. Turning-down the volume isn't a good solution because other important sounds are silenced.

With the help of the guys in the forums, looks like I have figured out a way to have TWO separate Sound Profiles (controllable with a switch; I used SA). One for flying with the GSC, and the other without. It's a combination of new Logical_Switches and Special_Functions.

I recently found-out that the Amber Sound-Pack (from 2017) has been slightly updated in the past few years. The new file I downloaded is 19mb and now has about 714 wav-files. I installed this on my Taranis-x9d (running OpenTX v2.2.1). It seems to work fine, and provides more Amber spoken words than the old file.

 

EDIT 2025: These tips were given to by RC-forum users, as I try to re-evaluate my RC gear and models after a break, and trying to remember how this all works. 

• Always keep the versions of the three OpenTX items the same - The main Taranis software, the BootLoader-Firmware , and OpenTX-Companion software on the computer. So yes, that is the version you want. The bootloader doesn't seem to be as critical, but still best practice to keep them all the same.
• The main thing is that you are already on 2.1 (or newer), which is when all the telemetry stuff changed. So going to 2.3 (and/or the final release) from that should be pretty straight-forward.

FrSky Taranis X9D TX Clock Battery Replacement.

It's flying season again, so I took my FrSky Taranis X9D transmitter down off the shelf. I haven't used it much in the past 6 months, but I do keep its main battery charged/cycled. I bought it new July-2014.

I noticed the Time was very wrong, and the Date was 1970. I tried to set the correct Date-and-Time several times, but it kept reverting back to 1970 after a simple power-cycle.

Turn off Taranis and remove main NiMH battery.
Loosen 2 of the switches a bit (just the top-two on the case-seam)
Remove 6 screws on back
Carefully separate halves and lay flay on table (don't strain cables)
Replaced tiny CR1220 3-volt lithium coin-cell battery.
- The old one was dead (down to 0.5-volts).
- Verify that the battery socket is clean (ie, no dust or corrosion)

- Carefully inspect and insure all internal connectors are still properly/fully connected
Re-assembled and tested radio.
Set Time and Date and test it's retention after a power-cycle.
Be sure Time and Date survives the radio being turned off for 15 minutes.
Mine tests good again.

FrSky Taranis X9D - Inside PCB and CR1220 coin-cell battery.
Open in a new Window or Tab to fully Zoom-In

EDIT: In January-2026 ... I still have and use this radio (but it's been in closet storage for a while). I had to replace the tiny clock-battery once again. The old one now reads only 0.1-volts. The new one I'm installing reads 3.2-volts.

A Good Indoor Beginner RC Drone Eachine E014 Windmill - WiFi SmartPhone FPV 2019

I like my new indoor WiFi 720p FPV Drone with Altitude-Hold (via optical-flow AI). This is the best beginner RC drone I have flown in a while. Very stable and easy hover. Auto-TakeOff, Auto-Land, and Altitude-Hold ...  all work fine.

Comes with a good/basic Mode-2 RC-Controller and SmartPhone-Clip for FPV.  I fly (Mode-2 like most people) with an old iPhone-5 clipped-on. I use 4- AAA Eneloop rechargables in black RC-Controller.

Connect Eachine drone to phone's WiFi.

WiFi Password: 12345678

Power-on RC-Controller. Watch the blue-lights on controller and drone.

Apple iOS App: Eachine Fly- Hailin Yi

Works on iPhone-5 (even with 16gb with old iOS-10.x) 

In Options (gear icon) , set to:

Scenery-Mode

Master-Mode (use controller). Model-2 = Mode-2
- Click X in top right to save/close.

Throttle (left stick) from Max-to-Min to ARM drone
- IIRC, you get a beep and last blue-led on RC-Controller goes solid-on.
Flight time is around 5-minutes indoors.
Just coreless-motors on this one (which are not too loud).

Nice RC-controller, on-board flight-controller, and position-hold abilities for a quad under $39 usd. There is usually a good coupon, but it only works from this page (and once per customer). I pay with PayPal. 

If you are new pilot, I suggest you stand behind the drone before take-off. Indoors, empty garage, or zero-wind is easiest. Don't fly over people, houses, traffic, or anything expensive. If windy, watch your position and altitude (to minimize fly-aways). Know before you fly outdoors.  

September 11th 2001 - 911 As It Happened - News Montage

Never Forget 911

                                                                                                     ⬆ Full Screen icon

Since I posted this, I have exchanged some private messages about this video with friends and family. On this 17th anniversary of this tragic event, I would like to say this:

I think it’s a good record of what happened that day. Yes, it’s hard to watch, but I think every American should (even young-people that are old-enough). Why are things the way they are now-days? Why do people feel they way they do? This is part of why.

There is very little bias … just a record of us all trying to figure out what the heck was happening that day. The whole world was watching also, and some felt powerless against the ruthless terrorist.

It seems they were circling and looking, but could not actually find the (relatively small) White House, so second target was the large Pentagon. Yes, I have been there. I think visiting Washington, DC is another thing every American should do.

The Flight 93 movie is also a good record of events. That airplane was likely destined for the Capitol building. Those passengers are true heroes. They are just putting the finishing touches on a monument dedicated to them. Here is a recent video about it.

Apple macOS High Sierra Upgrade

macOS v10.13 High Sierra - Downloading and Installing Upgrade

Some of you might be using Mac for your multi-rotors and drones, so I thought I would post my notes from my recent High-Sierra upgrade here.

I'm not one to upgrade my Mac's macOS that quickly. Maybe it's because this is an older Mac-Mini(Late 2012) or I currently really only use my Mac for iOS-App development.
However, I don't like to be more than one-version behind, so I at least like to upgrade before the next new final version is released. Let's get started.

Using Apple-Software-Update, make sure all applicable updates are installed to your existing/installed macOS first.

To download High Sierra for use with a bootable installer, be sure to download from a Mac that is currently using:
- High Sierra
- Sierra 10.12.5 or later
- El Capitan 10.11.6.
Enterprise administrators, please download from Apple, not a locally hosted software-update server.

Click the Upgrade button on top High Sierra banner of Updates page.
- After it downloads, the button will say DOWNLOADED. Installer-file is about 5.25gb
- If Installer auto-starts, close Installer for now.
- The macOS-Installer (*.app) file's normal download location is the Applications folder. There might also be a new Icon in LaunchPad for it.

Create macOS USB Recovery Drive
https://support.apple.com/en-us/HT201372
The best time to create this is after downloading installer/updater, but before installing it.
It seems that after it is actually (later) installed, the large 4-6gb file will be automatically deleted from your local HDD/SSD.

Disk-Utility and Terminal are located in the Applications/Utilities folder
Open Disk-Utility, and erase (format) a 16gb flash-drive as "MacOS Extended-Journaled" . Name it "MyVolume" .

For High Sierra, enter into Terminal:
sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ macOS\ High\ Sierra.app

Press Return after typing the command (copy and paste also works).
When prompted, type your administrator password and press Return again (Terminal doesn't show any characters as you type your password).
When prompted, type Y to confirm that you want to erase the volume, then press Return.
Terminal shows the progress as the bootable installer is created. (It takes a while)
When Terminal says that it's done, the volume will now have the same name as the installer you downloaded, such as "Install macOS High Sierra".
You can now quit Terminal and eject the volume.
This seemed to have worked fine.

Observations:
- Notice that as "createinstallmedia" starts, it again erases/formats volume as "MacOS Extended-Journaled".
- There is a 5.25gb installer-file on the drive now. The flash-drive is renamed and also made bootable.
- If you try to use this macOS Recovery drive later (and it does not work) you might have to temporarily change the Mac's date to now.
- Notice that Apple says you now need 11-12gb space on destination volume for High-Sierra. So, you must use a 16gb flash-drive this time
- - I think it writes the file twice, compares both checksums are correct/matching, and then deletes one (or similar actions).
- - This might help explain why it takes so long, and why you need double-the-space

Before starting actual upgrade:
If a Mac desktop, be sure it is connected to a good UPS (like an APC).
Disconnect un-necessary peripherals.
Made sure all applicable updates are installed to existing macOS first
- I noticed that this time it was still showing 2 INCOMPATIBLE Updates (Xcode 9.4.1 and iMovie 10.1.9). Another sign it's time to upgrade.
Be sure a TimeMachine backup has run recently, but is NOT currently running.
- I decided not first run a SuperDuper full-image this time (or mess with updating SuperDuper just yet). Might do later, afterwards.
- I set SimpleControl Hub App to not start on boot for a while

Installing macOS v10.13 - High-Sierra (as overlay upgrade).

Reboot and make sure no other applications are running.
Start the High-Sierra Installer/Updater.
- Agree to the license and install to your main drive (usually named Macintosh HD).
- Enter your admin login-password so High-Sierra can add Helper-Tool.
- You Mac will reboot and upgrade will start (even with a SSD, this phase takes about 45 minutes).
- Login normally
- Enter your password for Apple-ID. If you have more than one, take note of which one it is asking about.
- - iCloud might ask to make changes to your account. Enter your Mac's admin login-password
- Setup finishes and desktop appears.
- About-this-Mac says macOS High-Sierra (v10.13.6) is installed
- Restart/Reboot to start-fresh. Boot-speed seems about the same.

Look around a bit and test your favorite programs. Seems fine to me.
Check that your old data-files are still there (stuff you save in your named User Folder). Still there for me.
If you use iCloud, you can do a quick check by making sure your Contacts and Notes are there and still syncing with iPhone/iPad. Also, OK for me.

Go to App-Store.
- First, click on Purchased, and make sure you can see your Purchased Apps from over the years.
- - If you use a different Apple-ID for App-Store/iTunes Purchases, you will have to enter that other password now
- Now, you can go to Updates, Mac will be scanned, and you can install those final updates for Xcode and iMovie (and any others).
- Xcode updates are usually large and take a while, so I update Xcode separately.
Failure to do it this way will likely result in constant App-Store "wheel spinning"
- However, it might just be because I use two different accounts (a sharing-solution setup long-before Family-Sharing was an available feature).
After any of these primary Apps/Programs get updated, I usually run them once to make sure they still work and to see what's new.

Be sure your TimeMachine backup is still working. It might take a few hours before it's reporting properly.
- Eventually, it should do a large backup of arounf 10gb (takes about 60 minutes to complete).
- Seems fine to me (with no intervention required).

Noticed that my main macOS partition (on my Kingston SSD) has been migrated to APFS.
- Not sure why only this drive. My guess is because it is my only SSD, or maybe just because it is the main macOS partition.
My USB TimeMachine HDD was not (still MacOS Extended-Journaled)
My BOOTCAMP partition was not (still NTFS)

BootCamp:
Restarted MacMini (and held-down Option-key at chime) to boot native Windows-10/64bit (v1703) on my BootCamp partition ... seems to work fine. SIP is still Enabled (like its always been).
While I was in there, ran Apple Software Update (you might have to run it 3 times before it finds updates). Installed the newly-available "WiFi-Update for Boot-Camp".
Shut-Down Windows and restarted MacMini to automatically default-boot back into High-Sierra again.

I'm calling my High-Sierra upgrade successful and done. Hopefully this helps someone.

EDIT:
After 6 months, all is still working fine.

PixRacer Adv. Setup (PixHawk - ArduCopter) & OpenTX v2.2.1 Taranis Upgrade

My first PixHawk (PixRacer) build starts here.

FRS FrSky S.Port 
This should enable a lot of Telemetry to now run over the FrSky's 2.4ghz main link/channels, instead of using a dedicated SiK telemetry radio (for example).

On FRS connector, connect both signal lines together, and then connect to the S.Port line at X8R. Also, connect GND (black wires) but NO RED (Power) WIRE (X8R is already powered by PixRacer through RCIN connector).

Upgrading Taranis to OpenTX v2.2.1

I had to upgrade my older OpenTX version before the newer "Discover Sensors" was even available for use on Taranis.

It seemed to work fine going from old Open-TX v2.0.12 all the way up to v2.2.1 (all at once) on my FrSky Taranis X9D. Remember that you must also upgrade your OpenTX Companion for Windows to version 2.2.1 (so they match exactly). Remember that if you are ever connecting your Taranis radio to a NEW computer, check to see what version of OpenTX is running on the radio first (and then download and install the proper version).

I loosely followed DKEmxr's forum-post instructions and also some tips from Oscar Liang at this page. I backed-up the Taranis (to a computer file) first.

You should also document (or screenshot) the Logical Switches programming for any models that currently use them. As it turns-out v2.2.1 changes the variable names of Logical Switches from L1, L2, L3, etc. to L01, L02, L03, etc. and can't be fully migrated.

I used these Settings in OpenTX Companion v2.2.1:
My Radio
FrSky Taranis X9D (specify your exact model)
en (English for me)
lua and luac (only those checked, I dis-liked the way sq5font looked, so i re-did it)
Mode-2
AETR (what ArduCopter uses)
-
IIRC, I also erased the SD-Card and loaded a new set of files from sdcard-taranis-x9-2.2V0013.zip
And finally toward the end, I found and reinstall Amber (for Open-TX v2.2.x) .
Ok, now all it right with the world :)

Double-check your Logical Switch programming for those affected models. Check all parameters (including the "AND Switch" column).

NOTE: The above directions have been amended with changes resulting from May-2019 troubleshooting of "flight modes missing for some models after OpenTX upgrade".

With Open-TX v2.2.1 installed, now the "Discover Sensors" option is actually there. But so far, it reads RSSI (for RX) and RxBat (the default ones).

In Mission-Planner, the PixRacer's FRS (FrSky) port is Serial-4. So, set Baud = 57 and Protocol=4. Save that and Reboot PixRacer. Now, when you Discover-Sensors on Taranis, many (all ?) should now populate the List of Telemetry Sensors.

In the Model's Telemetry screen, you can assign Sensor fields to Main Page Flying Screen.

PixRacer ESP8266 WiFi Module

Since it's not "keyed" be careful to always connect like this little WiFi board this way. Be sure it's turned like this, and always use the 8 right-most holes.

On mine, the SSID was "AI-THINKER_code" by default. This is a good sign that the firmware is out-dated. While I could connect the laptop's WiFi to it, I was unable to establish a connection through it with Mission-Planner. DKEmxr says this tiny ESP8266 must be flashed with better firmware before it will work properly.

It apparently must be flashed to v1.1.1 (or maybe at least v1.1.0) . I used NodeMCU-Flasher. It will set SSID to "PIXRACER". It will also set the ESP8266's WiFi AccessPoint to be password-protected now (pixhawk). After running it, you should (might) be able to do further Firmware upgrades "Over the Air". While working with NodeMCU, it might help to disconnect from Internet and connect laptop only to ESP8266 SSID (AccessPoint/ HotSpot) via WiFi.

If your FTDI-wiring is correct, but you have trouble getting NodeMCU-Flasher to work, try swapping the wires for TX and RX (nothing should blow or fry just swapping those two lines). This ended-up being the reason my ESP8266 couldn't initially get MAC addresses in NodeMCU (and finally initiate the Firmware Flashing process). I followed the (simple) cable pin-out exactly so I think that maybe the silk-screened TX and RX labels on my new 3.3volt FTDI-USB Interface might be incorrectly swapped-around.

Communicating with PixRacer using Mission-Planner over WiFi (ESP8266 Module)

In the top right corner of Mission Planner, choose UDP. I don't think baud rate matters. Click the CONNECT button. If it asks for the Local port, enter 14550.

While I haven't tried it yet, I've read that it also works with QGroundControl.