Sunday, September 27, 2015

Nova External LEDs

Here are some notes about the Nova's external indication Red and Green LEDs.

The Red External LED mirrors the true Arming LED (that you can see through the Flight-Controller's white plastic case). Obviously, if the true one isn't lighting, neither will this external one.

The Green External LED mirrors the (tiny red) true GPS-Fix LED (on the bottom of the GPS-Module).

There is also a yellow LED that signifies various calibration modes.

The pinouts for the 4-pin black DuPont External LED assembly in here.

To test LEDs (to make sure a non-lighting one isn't burnt-out): After documenting plug orientation, you can disconnect it from FC. Then apply (properly polarized) 5 volts on the proper 2-pins sets ... to test each external LED. Do not reverse polarity or you might blow an LED.

JW57RC (in RCGroups forum) manually traced-out his particular LED assembly, and created this schematic

As for the (non-keyed) orientation of the black 4-pin Dupont plug into the Nova/Cheerson v252 Flight Controller ... there is only one way it must be plugged in. It also appears there are 2 different ways (because different wire colors were used), but in actuality, there is only one (it's all the same electrically). On my newer Nova v5.0 FC, it is orientated as above.

On my older Nova with v2.0 FC (below), it uses these wire colors. My best recommendation is to document your current stock and working way, and keep it that way. If it gets lost, you can match one of these two.
Here is a video about it converting them to work on a full APM FC.

Yet another pic that a helpful RCGroups forum member posted.

Wednesday, September 23, 2015

Cheerson CX-20 quadcopter RTF - On sale at lowest price ever

The Cheerson CX20 quadcopter is on sale again, but this time it's lower than I have ever seen it before. This is the "Open-Source" version so it has the desired APM-based Flight Controller. This is also the Ready-To-Fly model-bundle, so it comes with the Transmitter, LiPo battery, etc.

If you have been thinking about buying a CX-20 (or it's clone, the Quanum Nova) now would be a good time to make your move. If you already own the quad, it's also a good way to acquire a full set of spare parts.

This one ships from the USA warehouse with cheap shipping. Follow this link to get this deal at this price. I doubt this deal will last long.

RC_Danny (from RCGroups forums) reported you can use coupon code "newus" for another 8% discount. Seems to work, but like the main sale, I'm sure for only a limited time ... but it's a great deal either way.

Edit: Seems the sale is over for now, but see Comments below.

Friday, September 11, 2015

Telemetry Radios - Using FTDI-Interface and upgrading firmware

I'm setting up some new 3DR 915mhz Telemetry Radios for new Super-Nova. This is an older v1-set. To be able to use the one radio connected to Android Tower/DroildPlanner3 tablet on all models, all radios (including those inside quads) need to be set to the same Net-ID (channel) and other required settings. Basically, this allows you to use any two radios together.

I ran into two issues:
  1. While using Mission-Planner to reprogram the master radio (and reach the one installed in quad wirelessly) I "lost control" of remote/slave radio. I was using the "Copy Required Settings to Remote" button as normal so not sure how that happened. I later found out that the slave radio got it's Duty Cycle set to 0 (which I never touched). Obviously, it should be set to max or 100 (100 mWatts).
  2. Both SiK v1.6 and v1.7 firmware don't seem to save the "Max Window" setting properly. Looks like this has been happening for a while. You can set it to the MavLink default of 131ms ... but after reboot, it goes back to the "Low Latency" setting of 33ms. Obviously, this is not right. Max Window is also a required parameter that must match across radios, so that presents more issues.
Both issues seem to revolve around parameters/ settings and how they get saved.

So, I decided to connect each/all radios to MissionPlanner separately. If they had USB port (like v2 radios), fine. If no USB (like this v1 slave), I thought it would be a good time to try-out my new FTDI-Friend from Adafruit. Then, perform these steps:
  1. Upgrade to Firmware SiK v1.9 (directly from MissionPlanner). Also, reset params to Default.
  2. Decide what settings I wanted (see pic below), program them directly, and then Save Settings to each radio individually. No "copying across settings" required.
I like this FTDI-Friend with its full control of voltage and signals (seems versatile for other projects). In this case, the radio in the Nova is powered directly from FC's 5-volt main buss, so 5v is good for this use (nothing to change)

Connect power to two power-pins. Reverse RX and TX between the 2 devices. Works fine. Always be sure antenna is installed before powering-up radio. USB cable to laptop. Load MP, but don't click Connect. Just go to Optional Hardware/3DR-Radios.

All settings (including Max Window) now save properly on all my radios. Any two will talk to each other. If you haven't already, be sure radio works while in quad.

After you think you are finished programming a radio, return to main HUD screen in MP to reset radio programming screens. Then, do one last test of Load Settings (aka Read Current Settings) to verify settings before disconnecting. If you are sure it should be working, but it is not (maybe Remote radio isn't reading fully) ... trying going back to HUD screen or restart MP to reset.

If clicking Load-Settings/Read-Settings with 2 working radios, remember that sometimes you have to press "Load/Read" button again after first AT-sequence finishes. You should have the same settings on both sides. MP awards you with a double-beep on success. All fields on Remote side should have a black background (which means they were actually read-in). It also displays some interesting RSSI, ECC, etc. info.

As shown in this good SiK-radio video ... if you have both radios connected (one to PC and other by RF) ... in MP, you click
- Load Settings button
- Change whatever settings
- Copy Required to Remote (lower button)
- Save Settings button
This should keep the radios "in sync" even if you change Channel/NetID or other core communication parameters. This video was posted long after I wrote this post, but I thought it was good so I added it for your use.

Upload-Firmware-Local flashing from MP (to SiK v1.9) worked fine, even though one radio-set was v1 and other was v2. My existing set of radios were originally running firmware SiK v1.7 and my new radios were originally running SiK v1.6. It should be noted that previously, they seem to work together, regardless of firmware version (as long as settings matched). That was not the purpose of this sub-project (as there was not a problem there).

When green light is steady on radio, that means it found another to talk to. However, that doesn't necessarily mean that settings are exactly matching as they should be.

I like having ECC on. While official docs say it lowers overall thru-put, it is recommended and supposedly has better distance range. However, I think combining that with a Max Window setting of 33ms is a non-optimal combination. As you can see, I'm going to now try MavLink, ECC, 131ms.

Whether you are connecting a 3dr Telemetry radio (with built-in USB interface) or via a FTDI-Interface to computer's USB port, you should always get the Windows audio-alert that a new USB-Device has been connected. A new device also usually appears.

While I haven't seen any performance difference between v1 and v2 3DR 915mhz radio sets, I really like the convenience features of v2 over v1. v2 are:
- Matching transeivers, both with TTL and USB interfaces
- Either radio can be GCS (master) or inside quad (slave)
- Both can be programmed with MP directly via USB (no FTDI interface required).
- GCS (master) radio can be Standard-USB (laptop) or Micro-USB (Android OTG device)

Thursday, September 10, 2015

APM Power-Module install

My first APM Power-Module install . I used this PM with yellow XT-60. This one has a 5.3v BEC, but I'm not using it yet (still using BEC on Nova's PDB).

I carefully removed the proper pins from 6-pin PicoBlade and inserted into 3-pinner.

Black Sharpie marks the Ground pin. The other two are Voltage and Current Measurement.

Here are some supporting pics from FatQuad and DKEmxr on RCGroups Forums about PowerModule. This is a APM252_v5.0 FC (with ADC port).

From the pic below, using Pins 3, 4, and 5. Not currently using BEC/+5_VCC portion.

I used the main-power XT-60 connectors at first for initial hook-up and testing, but I eventually found them too cumbersome, so I spliced it in. You could also just re-wire and re-solder with proper gauge wires.

Settings & Calibration:

ArduCopter Power-Module Setup page

My Battery Monitor (Power Module) settings in MissionPlanner 1.3.37.

Using Turnigy 11.1v 2700mah 3s 20-30c LiPo.

Initial Setup/ Battery Monitor
Monitor 4:Battery & Current                  Battery Capacity: 2700
Sensor 0:Other
APM Ver 2:APM2.5+ 3DR Power Module
1. Measured Battery Voltage: 11.6v
3. Voltage Divider: 10.82
6 Amperes Per Volt: 19.1

For this Nova 2.52_v5.0 Flight Controller (ADC-Port Sensing pins) Parameters should be

Wednesday, September 9, 2015

Super Nova - Modding for flight

Never thought I would have two of these quads. Like I said, one is just for parts, but I figure ... why not have two brushless quads to mod differently and fly while they are both complete and working. It needs a model name, if for nothing else to differentiate between them in my Radio and also as I post about mods and flights here on the blog. I think I will call this one "Super Nova".

Steps here are not listed in order of importance, but rather in the order of completion. I will just edit this post until finished. Some sub-parts might link to other posts.

I suppose it starts here.

Removed foam-taped Flight-Controller and GPS-Module from Power-Board (PDB).

Added nylon washers to raise PDB about 2mm. Also, removed black foam-tape from bottom of battery compartment. This will help my Turnigy 2700 Lipos to insert and remove easier ( now that they have been exercised and puffed-up a bit) and also give a tad more room for other battery makes. Can't go too high because of other things planned. My two Turnigy lipos fit much better now.

Mounted FC with Zeal so accelerometer is near middle of quad. Cut some holes to route cables through middle (never cared for running them out the back anyway). Since PCB is not actually screwed down, installed single-sided foam tape to prevent any vibration inside case.

This is the bottom of the APM 2.52_v5.0 HobbyKing/Cheerson FC. Connected properly wired custom cable for UART (915mhz Telemetry radio). As posted elsewhere on this blog, Cheerson wired this UART-Socket exactly backwards or reversed. If your radios came with a pre-made cable, most pins will have to be carefully backed-out and moved. Red is +5v power and Black is Ground. As you can see, I did that at the FC side. I had the pin-out, but still verified VCC with a volt-meter at FC first anyway. This is ONLY for the v5.0 version of this FC. I think best to now keep this modified cable mated to this FC.

Installed the Power-Module (details) in ADC port also (black marked on socket is Ground). You can just use XT-60 connectors if you want, but I eventually found them too cumbersome.

I2C port is the existing compass cable. The socket came bent like that, but it ohms-out and solder looks ok so I'm not messing with it.

Connected FrSky X8R with FC with SBus-to-CPPM Converter.

Going to try GPS-Module foam-taped to top of FC. This should basically locate the GPS-Module in "the dome". The FC and GPS-Module are now a unit, and should still be isolated from copter vibrations with Zeal (no part of that unit is touching body).
Installed 3DR 915mhz on bottom-rear of Super-Nova.

RC Radio Setup and Config:

Using OpenTX-Companion, copied Model#1:"Nova" to Model#2:"Super Nova" and uploaded to Taranis. Radio is now programmed for new model (that was easy).

Flight-Controller (FC) Software Setup and Config in Mission-Planner:
  • Connect USB cable from laptop to bottom on Super-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 Reboot
  • Save initial v3.1.5 params to file
  • Click Disconnect in MP
So, this FC originally started on v3.1.2 (stock). No strange beeping now or since I started setup, but the next time I powered-up the Super-Nova, ESCs were beeping constantly. 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 only happens with a combination of ArduCopter v3.1.5 (or higher), ESC revision v1.6 (or higher), and an un-calibrated RC radio.
  • Connected other 3DR 915mhz Radio to laptop and click Connect to Super-Nova by radio
    • The FC was not "locked up" and there was no problems connecting to it.
    • While I started using my 3DR-Radio for the remaining setup steps, you could also choose to use a wired USB cable.
  • In MP, calibrated Radio, write params, click Disconnect and power-cycle (reboot) FC.
    • Since the radio is already programmed, in addition to the sticks, step thru all the pre-programmed Flight-Modes on the switches. All channels should move (except CH6 which is not assigned to anything on Taranis).
    • If ESCs were beeping they should stop now.
  • Set Frame Type to X-Y6A
  • Click Connect and calibrate the rest of the "Mandatory Hardware" devices. Accelerometer was usual procedure (keep still and perpendiclar). Before starting Compass, I went outside to get basic GPS-Fix for Auto-Dec. Final offsets were -125, 8, -33.
At this point, I'm still running only the ArduCopter v3.1.5 Default Parameters and tuning PIDs.
Some notable Default params are:


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 on dedicated Taranis buttons)

Changed these non-Default parameters:



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

Completed SuperNova assembly.

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

Ready for maiden flight.

If it survives, I'll then work on adding a camera and/or gimbal.

EDIT: Results of maiden flight are here. It flies great.

Tuesday, September 8, 2015

Xiaomi Yi Camera

Well I got my Xiaomi Yi from Amazon in 2 days. Pretty cool little camera. This post will be edited as I find out more about it and use it in the next months.


RCGroups thread

My Camera Version: YDXJ_v22 (aka z22)
My Current Firmware: v1.2.12 (Stock/Shipping firmware was v1.0.2)

My current SD-Card: Lexar 32gb Micro-SDHC Class-10 UHS-1 (300x-45MB/s)

While I could have used my (mainly DroidPlanner) Android tablet (and what I suspect is a more mature App), I carry an iPhone-5, so I downloaded it's newer iOS App version: v1.12 from the App-Store. All my usage notes (for now) will be with this app.

I had to connect to the Yi's WiFi via Settings like a conventional HotSpot. I ignored the Yi firmware update a couple of times, but on the third run or so it just decided to do it anyway. It did it over WiFi. At the end (after the Yi turns itself off) you turn it back on manually and it's done. Anyway, that's how it's firmware got updated so soon. The App didn't update, but the Yi now has more options.

Took some videos and pics and it works fine so far. Battery seems to last about an hour, but there is a lot going on inside this little camera. From completely off, it takes a few seconds to boot-up. Would have been nice to get a lens-protector.

At the time I ordered from Amazon (Sept. 2015), I got the z22 version. Mine seems to work fine. Not sure if there is much of a difference, but they also have the new Xiaomi Yi z23L version . I doubt there is much of a difference (likely just the latest revision). There is also now an official USA Edition (so get that one if in USA).

Usage Notes:

So, you can use the camera's WiFi while on the ground, but be sure to turn it off before taking off. Both 2.4ghz RC (main Radio-Control) and WiFi/Bluetooth operate on similar 2.4ghz frequencies. They will generally interfere with each other, as this video demonstrates. In this video, notice how poor the range and thru-put gets (laggy) as both fight to use the same 2.4ghz band.

Battery last for 60 minutes (recording at 1080p@30fps) at that video fits on 32gb SD-Card.

In May 2017, iOS App (on iPhone-5s) is updated and still works fine. Downloaded latest camera firmware.

Monday, September 7, 2015

DJI Phantom 3 STANDARD is Released for $699

We all expected that (due to the previously released Phantom-3 model-names) a Standard edition would eventually be released. I'm no DJI expert, but it looks like the main difference between the Standard and Advanced/Professional is the RC-radio and non-Lightbridge video transmission system ... it seems more like the Phantom-2 (but still a bit better).


Compare the Phantom  Series

Phantom 3 Pro./Adv.

Phantom 3 Standard

Phantom 2 Vision+


USD $999 (Advanced)
USD $1,259 (Professional)

USD $699


Created For

High-level aerial photography and cinematography

Beginners & First-time pilots

Beginners & First-time pilots

In The Box

1. Phantom 3 Professional or Advanced Aircraft
2. Phantom 3 Pro./Adv. Remote Controller
3. 3-Axis Camera Stabilization Gimbal
4. Built-in Camera Captures 4K (Pro) or HD (Adv) video & 12.4M Photos
5. DJI Lightbridge Video Downlink, 2km range
6. 4S 15.2V 4480mAh Intelligent Flight Battery
7. Four Pairs of Propellers

1. Phantom3 Aircraft
2. Phantom 3 Standard Remote Controller
3. 3-Axis Camera Stabilization Gimbal
4. Built-in HD Camera Captures 1080p HD video & 12M Photo
5. 2.4G WiFi Video Downlink, 1km range
6. 4S 15.2V 4480mAh Intelligent Flight Battery
7. Four Pairs of Propellers

1. Phantom2 Aircraft
2. Phantom 2 Vision+ Remote Controller
3. 3-Axis Camera Stabilization Gimbal
4. Built-in HD Camera Captures HD Video & 14M Photos
5. External 2.4G WiFi Video Downlink, 700m range
6. 3S 11.1V 5200mAh Intelligent Flight Battery
7. Four Pairs of Propellers


Diagonal Size (Excluding Propellers)

350 mm

350 mm

350 mm

Weight: (Including Battery and Propellers)

1280 g

1216 g

1242 g

LiPo Battery

4S, 15.2V, 68WH 4480mAh Intelligent Flight Battery

4S, 15.2V, 68WH 4480mAh Intelligent Flight Battery

3S, 11.1V, 57WH 5200mAh Intelligent Flight Battery


Remote and Flight Battery Charger
Professional: 100W Charger
Advanced: 57W Charger

57W Flight Battery Charger
Remote is charged via USB

50W Flight Battery Charger
Remote is charged via USB

Flight Time

About 23 mins

About 25 mins

About 23 mins

Max. Flight Speed




Positioning Module

Outdoors Positioning Module

GPS+GLONASS Dual Positioning Module

GPS Positioning Module

GPS Positioning Module

Vision Positioning Module

Vision Positioning System with ultrasonic sensors (Position holding without GPS)



Hover Accuracy

Vertical: +/- 0.1 m (when Vision Positioning is active) or +/- 0.5 m
Horizontal: +/- 1.5 m

Vertical: +/- 0.5 m
Horizontal: +/- 1.5 m

Vertical: +/-0.8m
Horizontal: +/- 2.5m



Sony Exmor R BSI 1/2.3", Effective pixels 12.4M (Total pixels 12.76M)

Panasonic Smart FSI 1/2.3", Effective pixels 12M (Total pixels 12M)

Aptina 1/2.3 ", Effective pixels14M

Video Resolution

Phantom 3 Professional
UHD: 4096x2160p 24/25, 3840x2160p 24/25/30
FHD: 1920x1080p 24/25/30/48/50/60
HD: 1280x720p 24/25/30/48/50/60
Phantom 3 Advanced
FHD: 1920x1080p 24/25/30/48/50/60
HD: 1280x720p 24/25/30/48/50/60

FHD: 1920x1080p 24/25/30
HD: 1280x720p 24/25/30/48/50/60

FHD: 1080p30 and 720p

Max. Image Size

4000 x 3000

4000 x 3000

4384 × 3288


FOV 94° 20 mm (35 mm format equivalent) f/2.8
focus at ∞

FOV 94° 20 mm (35 mm format equivalent) f/2.8
focus at ∞

FOV 140° f/2.8
focus at ∞

Filter Ring

Yes, Removable to Allow for ND Filters



Remote Controller & Video Downlink

Dedicated Buttons on Remote

Return Home Button


Return Home Switch


Video Recoding Button




Shutter Button




Playback Button




Flight Mode Switch




Gimbal Dial




2 Dedicated Customizable buttons




Max Transmission Distance

2000 m (outdoors and unobstructed)

1000m (outdoors and unobstructed)

800m (outdoors and unobstructed)

Video Transmission System

Built-in DJI Lightbridge Video Downlink

Built-in DJI WiFi Video Downlink

External DJI WiFi Video Downlink

Video Transmission Distance

2000m (outdoors and unobstructed)

FCC: 1000m
CE: 500m (outdoors and unobstructed, flight altitude 120m)

500-700m (outdoors and unobstructed)

Max. Video Bitrate

Phantom 3 Professional10Mbps
Phantom 3 Advanced



Max FPV Preview Quality:

HD 720P @ 30fps (depending on conditions and mobile device)

HD 720P @ 30fps (depending on conditions and mobile device)

SD 480P @ 30fps(depending on conditions and mobile device)


Mobile App




Intelligent Flight Modes

Follow Me
Point of Interest
Course Lock
Home Lock

Follow Me
Point of Interest
Course Lock
Home Lock

Course Lock
Home Lock
Ground Station

1.         Max Transmission Distance was measured in a test environment and is for reference only. Actual values may vary depending on local flight conditions.
2.         Max Flight Time was measured in a test environment and is for reference only. Actual values may vary depending on local flight conditions.

Here is some sample Phantom-3 Standard footage. If you are looking for an entry-level, pre-built quad, and Aerial Photography (AP) is all you are really into ... it's looking pretty good. If your connection supports it, try 1080p and full-screen.

Anyone else notice how stable the train-station video was?