Wednesday, November 22, 2017

Setting up Nova from scratch

OK, I'm down to just the one Quanum Nova now (and with plenty of spare parts). Last year, after this Nova #2 flew it's maiden and a couple of other flights, it blew an ESC. After I repaired it, I was having problems getting the accelerometer calibrated. It's been sitting in this limbo state in the shop since then. The hardware is done and it's closed up. It's fairly stock, but does have the newer APM-252_v5.0 FC and a Power Module (unlike my old one). I decided I'm just going to just "format it" and start over from scratch. 

RC Radio Setup and Config:

Using OpenTX-Companion, copied my old Nova model to a new one and uploaded to Taranis. Radio is now mostly programmed for new model. Since this is a X8R, of course the TX and RX must be bound-together using those normal procedures. You have to touch the RX, so do this before closing-up the Nova. 

Flight-Controller (FC) Software Setup and Config in Mission-Planner:

When you first use Mission Planner (MP) to Connect to the APM Flight Controller (FC), it retrieves the current parameters from it so you can work on them. When using MP, it's important to remember to click the Write button to write the parameters you just changed to the APM-FC before Disconnecting or closing the program. This includes any calibrations you just made, because calibrations are also just saved as parameters in the param config file. After you Write them to the FC, you can optionally Save them (as a file) for later Loading or Comparisons. Just because MP presents telemetry in Real-Time in some parts, don't confuse that with parameters. For params and calibrations, MP is just a temporary holding or work area.
  • Connect USB cable from laptop to USB-Mini Port on bottom on Nova
  • Start Mission-Planner and click connect to test port and Connect ability.
    • Use Auto at first if you don't know com-port and baud rate
    • Click Disconnect but leave cable attached
  • Upload and Verify Custom Firmware file v3.1.5 (from VinnieRC) aka v3.1.5c
  • Click Connect
  • Reset (Parameters) to Defaults (for v3.1.5) and let it Reboot.
  • Save initial default v3.1.5 params to file (for future reference)
  • If not already Disconnected in MP, do so now.
  • Shut-Down MP, disconnect cable, and power cycle Nova.
Since I just re-loaded the firmware, I've learned it's normal for the Nova and ESCs to start beeping constantly on next full powered-up. 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 v3.1.5 (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, calibrate the RC Radio, 
    • The sticks, 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).
    • Write params, click Disconnect and power-cycle (reboot) FC.
    • If ESCs were beeping before, they should stop now.
  • Verify or Set Frame Type to X-Y6A (Nova is a X-4 quad-config)
  • Recall you have the APM-FC mounted and orientation in normal/forward
  • Verify Compass settings (mine in a fairly unique mount requiring yaw 90 degrees)
  • I would say this is the minimum parameters you want to set or verify before calibrating:

AHRS_ORIENTATION,0
COMPASS_EXTERNAL,1 
COMPASS_ORIENT,2 
COMPASS_USE,1
FRAME,1

  • Click Connect and calibrate the rest of the "Mandatory Hardware" devices.
  • Accelerometer calibration was NOT the usual procedure. I'm not sure if it's this special little AMP-252 FC, the AC-v3.1.5, or Mission Planner-v1.3.50 ... but I was unable to calibrate the accelerometer the normal way. I had to use Terminal. 
    • Set to APM and click Terminal's Connect Button
    • Go to Setup / Accel
      • Remember that ? or help shows the current menu commands, and exit moves back one level
    • 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. I think it might Write them to the FC at the end.
      • However, to be sure, I take a phone pic or screen-shot. Later, you can verify as INS_??????? in params list.
    • Return to Full Parameters List and Write them. You might need to Connect first. Finally, I Save as a File since we made it this far. 
  • Before starting Compass calibration, I went outside to get basic GPS-Fix for Auto-Dec. Final offsets were -125, 8, -33.
At this point, I'm still running the ArduCopter v3.1.5 Default Parameters and default tuning PIDs.

Calibrated ESCs (especially since this is a PnF model).

Set my Flight Modes in MP interface (and write/save):
1. Stabilize
2. Loiter
3. Alt-Hold
4. Drift
5. Land
6. Auto
... and in Extended Tuning, CH7=SuperSimple and CH8=RTL
(which I have each on dedicated Taranis buttons)

The above should change these Flight-Mode parameters:

FLTMODE1,0
FLTMODE2,5
FLTMODE3,2
FLTMODE4,11
FLTMODE5,9
FLTMODE6,3
CH7_OPT,13
CH8_OPT,4

Also, verify or change these parameters (some might be defaults):

ANGLE_MAX,4000
GPS_HDOP_GOOD,220
LAND_SPEED,40
LOG_BITMASK,958
MOT_SPIN_ARMED,0
RTL_ALT,2500
THR_MAX,1000
THR_MID,530                         (Only payload is small SiK 915mhz Telemetry radio)

WP_YAW_BEHAVIOR,1

BATT_AMP_OFFSET,0           (This set is for installed Power-Module. Notice PINS)
BATT_AMP_PERVOLT,19.1
BATT_CAPACITY,2700
BATT_CURR_PIN,12
BATT_MONITOR,4
BATT_VOLT_MULT,10.42846

BATT_VOLT_PIN,13

FS_BATT_ENABLE,0              (This set is the Fail-Safe actions)
FS_BATT_MAH,0
FS_BATT_VOLTAGE,6
FS_GCS_ENABLE,0
FS_GPS_ENABLE,1
FS_THR_ENABLE,1

FS_THR_VALUE,975

Tested Fail-Safe with no props installed (passed).

Completed Nova assembly.

Armed and carefully did low-throttle "hold by landing gear" test. Also, verify flight modes (passed).

Ready for it's test flight after rebuild #2.

Tuesday, November 21, 2017

Cheap 3D gimbals for sale (Tarot & Feiyu-Tech)

I was just browsing online the other day and came across these inexpensive 3D Tarot gimbals. I don't actually own one yet, but I remember that the Tarot name is good and it shows by the reviews. I've had good luck with this place over the years. No problems shipping from China and even acceptable shipping speed.

I noticed they also have the popular Feiyu-Tech 3D gimbals on sale. Check-out their accessories, it's like they thought of everything. For instance, no hardware hacking is required to switch between Xiaomi Yi cameras and others.

Speaking of cameras, if you don't have a GoPro yet, I think the GitUp Git2 is a good lower-cost alternative.

I guess it's that time of the year again. Some of these Black Friday RC deals look pretty good.

I've been working on my Novas a bit since Saturday. Between the two of them, I hope to get a single one flying soon.


Sunday, November 19, 2017

I've had better days at flying field. Rough Nova RTL landing with damage.

TL;DR - Pilot error and high-winds results in rough off-target RTL landing, with Nova's egg-shell body cracking in previously repaired spot.

With my life schedule and the weather, it's been a couple of months since I've had a chance to go fly.

I started watching the weather, and this weekend looked good, except for a cold-front blowing-in on Saturday. Since we had plans for Sunday, it was Saturday or try again next week.

On Saturday, it was Clear and 75f, but winds at 2:00PM were 22mph (with gusts to 30mph). I'm a little rusty, so I don't think I will do good enough in 22/30. And since it's likely faster higher-up, I'm not so sure about stock Nova/CX20 either. About 4:00PM I saw that winds had calmed to 12/20 so at the last minute, I decided to go for it after all. Over the years, I have successfully flown the Nova "in some wind".

At the school's big flat football field, it seemed really windy after all. I installed my small 2200mah battery. Within a few minutes I had 11 SATS and HDOP=1.5. All systems go. It was a little scary at first, but I flew through the first small battery successfully. I kept it fairly low, flew Alt-Hold, tested Loiter (noticed it fighting from being pulled down-wind),  and practiced my manual Landings in Stabilize.

Second battery was my larger 3000mah. Still had SATS and around HDOP=1.5. Flew around the field at little further out now, and trying some other flight modes on the Taranis. Then, I heard it ... "Proceeding to WayPoint-1". I was like "What The Hell is Happening!". I looked down and I had apparently accidentally flipped the Auto-Mission switch on the Taranis somehow.

At this point, the Nova was pretty high and heading for the back-corner edge of the school property ... the baseball diamond about 150 meters away. This was an old mission from a couple of years ago. It was programmed at high-altitude due to the metal high-power towers in that back corner of the school property. Across the street corner, there is a tall church and houses all around. I PANICED since I've never un-intentionally started an old Auto-Mission. I turned the Auto-Mission switch off and switched to Loiter, but the quad was now high and far away ... it seemed to be drifting away.

I tried to control it back closer, but it seemed I was making it worse. At this point, I'm pretty frazzled and I just want this flight to be over, so I switch on RTL and it starts coming back really fast (with the wind) but still pretty high since IIRC, my RTL altitude is set to 40meters (to prevent hitting anything along the way). When it gets above the Landing spot, it starts to descend finally. But of course the wind decides to start gusting. The quad is fighting it, descending, and drifting down wind.  It finally lands, but brushed-up-against a small tree (on the other edge of school property now) so the last few feet was a little too fast :). To tell you the truth, I was just glad the ordeal was over. Tower informed me of the crash (thanks Tower) and the Nova was still on and sending telemetry.

The only damage was the Nova's egg-shell body cracked and broke where I had glued it back together 3 years ago. The props, motors, ESCs , landing-gear, (everything else really) looks fine. If it wouldn't have been for that tree (in the way of that off-target RTL) I think it would have survived un-damaged.


So, I guess I have plenty of spare parts for my other Nova now :) Time to get that one calibrated-up and flying again.

I've tried to evaluate this flight and plan to be more prepared to do things differently next time. I also notice my ANGLE_MAX,3000 .  I had it raised a bit, but still kinda low to be docile. I plan to raise it higher since that would have probably allowed the RTL to land more on-target on the football field (even in the steady 20mph wind).



Friday, November 17, 2017

Mission Planner v1.3.50 for Windows (for APM and PixHawk)

Well, I recently posted about the other GCS I use (or plan to use) so I thought a post about the main one I use would be in order. Glad to see Mission Planner (for Windows) is still going strong (thanks to Michael Oborne , all the project contributors in the community).

I came across an interesting glitch late last year. It has apparently since been fixed in the latest version of Mission Planner (v1.3.50), but I thought I would post about it anyway.

With the old version of Mission Planner v1.3.41 (current back in October 2016) I tried to load it on a fairly new Dell laptop (with Intel mobile CPU and Intel on-board HD4000 IGP) running Windows-10/64bit. It seemed to lockup while trying to initially load and start running. I didn't think much of it and just put that laptop aside. Instead, I used my slightly older AMD-based Lenovo laptop (also running Windows-10/64bit). It ran fine there, so no worries and back to flying :)

I recently found out that it wasn't actually locking-up on the Intel-based Dell, it just goes unresponsive for about 4 minutes and then finally loads, initializes, and runs properly (if you wait-it-out). I was still running v1.3.41 and holding-off on updates. However, Google searches reveal other pilots having similar problem with versions as late as 1.3.45 and 1.3.49.

So, in the v1.3.50 Change Log, we see:
HUD: fix Intel graphics freeze

However, it might have been a different issue that was fixed. Anyway, its fixed and now works on both laptops. The Intel-base one is running Windows-10 Pro 64bit Version: 1607.

To get Mission Planner v1.3.50, you can update from inside the Mission Planner program itself, or just install the latest version from the installer-file.


Thursday, November 16, 2017

QGroundControl v3.2 - Initial Impressions

Looks like the QGroundControl is coming along and maturing nicely. I finally had a chance to load this open-source GCS on my Android tablet.



I think it looks great. I think I also prefer the UI and compared to what Tower has become, including the representation of the fundamental Aircraft Instrumentation.

Amazingly, it connected right-up to the APM in my Nova over the SiK-915mhz radio ... and the UI came to life with real-time telemetry from the aircraft. The Android-girl was even calling-out Mode changes as I tested the Taranis.

However, I immediately got a pop-up notification warning-message that v3.3 or higher is required for 100% proper operation. I assume it means ArduCopter because this little APM-252 FC is just running v3.1.5. Ground testing seemed fine, but as I explored the app, I continued to get various other warnings about yet other parameters being missing. It's not a fault of the App, just that this version of ArduCopter isn't new enough (and can't particular FC really be upgraded to v3.3.x).

I still plan on using Mission Planner for Windows for quadcopter and drone setup, calibrations, and parameter tweaking ... while at the workbench. While this seems to be barely working on my old APM aircraft (on the ground) I think I will stick to Tower 4.x for them. I'll reserve this QGroundControl for my PixHawks.

Saturday, November 11, 2017

Tower (for Android) 4.0 and Tower Beta 4.0.1 - GCS Testing

Tower v4.0.0
Well, the first couple of times I ran the Tower GCS, after a few minutes it just quit while it was running and dropped to the tablet's HomeScreen. While later researching Tower for this post, I came across some post by other pilots describing similar crashes. Not sure what's up with this, but it's rather off-putting ... I use Tower during most flights and I can't have it crashing. I don't recall any old versions over the years crashing for no reason.

Since they aren't required any more, I tried a long-shot fix ... I un-installed 3DR-Services, and rebooted. Then, and un-plugged/re-plugged the USB cable for the 915mhz SiK-Radio and answered the prompts to use Tower as default App.

Luckily, it seems to run fine now. I ran in many times and no more crashing (but I'll watch it closely). In fact, it works fine now except no RSSI is shown (under the triangle-looking icon). Just confirming a know bug.

Tower Beta v4.0.1
Installed from Google-Play store and rebooted.
Un-plugged/re-plugged the USB cable for the 915mhz SiK-Radio and answered the prompts to use Tower Beta as default App.
Set my desired Settings and Preferences.

Connects fine and NO crashing to HomeScreen... seems to run fine.
However, there is still no RSSI shown. Interesting, because Release Notes say that it was fixed by the new Developer/Maintainer. I was hoping it would work, but I did read a forum post by another user that said it was still broken for them also.

Hmm. Maybe there is a newer compiled version in .APK file, that just hasn't been vetted or uploaded to Google-Play yet?

There is not really a full manual for Tower that I've ever seen. If you are new to Tower, or just need a little refresher course, these 4 videos by RNDrones seem informative and helpful to me. They might be for a 2016 version, but other than not needing 3DR-Services now, they should work fine with v4.x .


Thursday, November 9, 2017

What's going on with the Tower app (for Android) lately ?

As you might remember, I use the Tower app (previously known as DroidPlanner) while flying my APM-based quads.

So, I'm trying to spend more time with this hobby lately. One of the things I was checking was what software I should be using, and that everything is up-to-date.

I don't really use Android for anything other than this R/C Tablet, so bear with me (in real-life I live in Apple ecosystem). For some reason, the "auto-update-apps" setting in Google-Play Store was off on my R/C Android tablet, so I turned it back on and various Apps updated. I'm not sure if my last flights were on a late release of Tower 3.x or v4.x.

When I started Tower the first time, I got a "Change-Log" screen. Among other things, it said that the dependency on 3DR-Services had been removed. At the time, I didn't think much of it, other than the fact that my R/C tablet's software-build could now possibly be a little leaner.

At first, I thought the Tower v4.0 release was new. However, after doing some research, it looks like v4.0 was released back in Q4-2016.

Maybe the removal of 3DR-Services had a deeper meaning of things to come?

It appears that Bill Bonney  https://github.com/billbonney has come to the rescue.

https://discuss.ardupilot.org/t/tower-4-0-1-beta-released/17037

Bill, thanks for Tower Beta v4.0.1 . I think this might be the main GitHub dev page

https://github.com/billbonney/tower

Looks like its in the Google-Play store, so we doesn't have to hassle with a .apk file.

https://play.google.com/store/apps/details?id=org.droidplanner.android.beta

The main Tower dev page is here.
https://github.com/DroidPlanner/Tower

It appears to being updated slightly recently, but a new version with those updates is not always uploaded to Goggle-Play-Store. Evidence of that is its Tower is stuck at v4.0.0 since 10-2016.

https://play.google.com/store/apps/details?id=org.droidplanner.android&hl=en

Next, I need to fire-up the Nova and Tower v4.0 and see if the RSSI for my SiK (915Mhz) Radio is truly missing. I do like seeing that . Not just when flying far away, but also as a Pre-Flight check.

Tuesday, November 7, 2017

Cheerson CX-20 still for sale

Looks like the Cheerson CX-20 (APM Open-Source version) is still for sale.

If you are still flying this nice little brushless quad-copter, now might be a good time to pick-up another RTF package. You will get a spare battery and lots of spare-parts (landing-gear, body shell, motors, ESCs with LEDs, APM-FC, etc.).

Shipping from USA-warehouse will likely be pretty quick.

8% OFF Coupon Code: bggcx-20 (special limited-time code for CX-20 Quadcopter)

If this is your first CX-20/Nova, you might want to read my blog's archives for tips. Like ... throwing-away the included cheap battery-charger (and buying yourself a "real" LiPo charger for $30 usd) :) The LiPos for your new hobby will thank you.

UPDATE:

Right after I posted this, I found another tip posted by DKEmxr in the forums. Looks like HobbyKing still has some Nova's left as well. It's the PNF package (no battery or radio) but it's only $129usd. Remember that the Cheerson CX-20 is the quad that HobbyKing cloned to make the Nova.

Monday, September 11, 2017

I'm back. My weekend Flying Session and Multi-Rotor Sale notification

I bet you all thought I disappeared from the scene :) No, I'm still alive. It's just that "life" has been getting in the way of my hobby :) It's been really crazy around here lately.

I think I got to go fly my quads like maybe 4 times all spring/summer. FPV racers are mostly just sitting on shelf and custom-build 550 hexa is still waiting for assembly. I have been maintaining my LiPos though (or, at least checking them).

It was kinda windy this past weekend, but the weather was otherwise good, so I decided to take the Nova over to the middle-school for a little flying.

I flipped though the Taranis switches and tried to remember how to do a proper pre-flight and actually fly this thing. It took a while (updating GPS almanac ?) but I finally got a good GPS lock (sats and hdop). I thought it would be OK if I use Manual-Mode sparingly ... instead relying on Loiter, Altitude-Hold, etc.

I had a couple of scary moments, but I flew-thru 2 batteries without any major damage. I also practiced my landings. I was glad to see I could just go fly the Nova after all these months. Not just with my rusty skills, but also that the Nova was still calibrated. Not sure if the version of Tower on my TX-attached Android-tablet is the latest, but it seemed to be working (but didn't try any auto-missions or anything).

Hey, one of my primary affiliate partners just notified me of a limited time sale on multi-rotors and drones. This link and code are only good for a limited time, but if you need something, you might want to check it out.


Extra 20% Off For Multi-Rotor & Accessories DealsUp To 71% Off For FPV Racer and Multi Rotor Parts.



Saturday, January 7, 2017

Electronics and computerized machines fail early due to Lead-Free Solder and RoHS techniques

Have you ever wondered why electronics and computers from the 90's and early 2000's seem to last forever? But now, you are lucky to get 3 years from just about anything computerized. Now-days, just about any machine (including vehicles, boats, and airplanes) have some kind of logic-board or PCB installed. From coffee-makers to TVs, computers, and spacecraft ... and everything in-between.

So now we know why. It's not just a conspiracy theory. Are the machines you purchased any less valuable or important that the ones that NASA's and the US-Military bought?

Lead-Free Solder - A Train Wreck in the Making

The advisory concludes with this guidance: “Though there are many alternative solder alloys available to replace traditional tin-lead, none of them has passed the reliability testing required of aerospace-quality hardware.”

Killed (Not Saved) By A Whisker - Why Our Electronic Gizmos Inevitably Die

The military and NASA were especially concerned, so they generally operate under waivers allowing lead solder in the gear on which our space program or national security supposedly depend.

Military Suppliers Confront the RoHS Challenge

The two main reliability concerns with lead-free processes are solder joint reliability and tin whiskering ... Most discrete parts and parts with leads can withstand the temperatures of both leaded and lead-free processes, but BGAs can be a problem.

Hazardous Materials Statement - Amphenol Aerospace (PDF)

Due to stringent customer and Mil-Spec requirements, AIAO will not pursue 100% transition to Pb-free products ... MS and other mil-specification part-numbers requiring leaded solder will not be made available in lead-free or RoHS compliant versions until the applicable MilSpec is revised to incorporate this change.

I think this inferior unleaded solder is killing more electronics than we realize. Reliability and longevity seems to have fallen from around 95% to around 60% ... on just about everything. I used to think it was just poorly executed Lead-Free solder techniques, the additional solder-heat weakening the soldered components, and more recently ... a large industry shift to BGA components. While I'm sure all this is still true, now we know the main reason. It only takes one bad/cold solder connection or weak PCB multi-layer-via to render a machine inoperable. Your thoughts?