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Sep 17, 2019, 11:12 AM
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Here is the general overall view of the groundstation... And the bucket is provisional seat.
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Sep 17, 2019, 11:14 AM
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Here you can see all of the controls which are installed so far (with room remaining for antenna tracking controls and Autopilot controls).

The white box on the right is airplane functions expander:

There are three trims on the right side, and two sensitivity switches for manual and stabilized modes, respectively.
The left upper corner has six switches which activate different functions on the airplane; in my case, the first one (HTR) is Servo heater which turns on heating for the servoes for flights at temperatures below 30C. The second switch in my case is HD Runcam 2 Reset; Runcam has a problem that it sometimes dies at temperatures below 35C so you have to disconnect the power and reconnect it.

The switch below with three lights is the AP mode switch. Pitlab AP which I am using operates using a AP Mode selector (Manual - Stabilized - Auto), and then the submode is selected using throttle position (High - for circling, Medium - Hold, Low - RTH). The AP Mode selector is the left-most control on the black throttle unit. Now, when in Manual or Stab mode, my system uses the position of the big fat black throttle to set engine power, however, once switching over to AUTO mode, the system takes the position of the small switch with blue -yellow -red lights as source of the submode.
Last edited by chileflora; Sep 17, 2019 at 11:27 AM.
Sep 17, 2019, 11:28 AM
Registered User
Very nice!! Looks professional!! Great work chileflora!!
Sep 17, 2019, 11:30 AM
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The left white box is responsible for groundstation functions:
Left upper corner has the controls for the main Dragon Link TX:
Source: can be either groundstation itself or an external radio
Bind: the bind button
TX PWR: switches on and off the main DL TX

Then comes a row of flip switches:
Basically, you can select as source different video lines:

For the Main Monitor:
HDMI feed, either directy from Antenna Unit (DIR), or after passing through DVR (DVR). The difference is that the quality is slightly higher with HDMI DIR, but you may get blue screen with the monitor I am using, or slightly lower but no risk for loosing video with DVR.
RCA feed, with the same two options.

For the Small Auxiliary Monitor:
Either RCA DVR (safe option, always on), especially useful if you set main monitor to DIR, so if you loose signal and get blue screen, the Aux Mon will continue to show video feed coming from DVR.
Or external camera view. I plan to install a camera on tripod with tele lens so that one can see where the antenna is pointing and if there are any treees or other close-by obstacles which may obscure the Line of Sight.
Last edited by chileflora; Sep 17, 2019 at 11:54 AM.
Sep 17, 2019, 11:36 AM
UAV Flight Operations Manager
Wow! Amazing work!
Sep 17, 2019, 12:00 PM
Registered User
The next row of buttons:
Main Mon PWR: Turns on and off the main monitor remotely (I simply had to hack the monitor, and to extend cables to the white box.)
RCA/HDMI: Also a hacked button, simply allows to select the video source for the main monitor, in my case it can be either HDMI or AV (RCA).

The final button (HDMI SRC):
When monitor is in HDMI mode, this button allows to select a HDMI feed source (through a HDMI switcher), so that one can display either the FPV feed or the raspberry PI output.

The next row of 4 buttons are the four Video channels (=VRx) on the antenna - you can switch from 3 dBm rubber duck antenna all the way up to 30 dBm 90 x 60 cm dish antenna. With a small 11 dBm patch and larger 21 dBm pannel antennas inbetween...

Final button (KBD PI/PC): I have a raspberry Pi, but also there is a slot for inserting a Pc notebook into groundstation, however, the keyboard of the notebook is hidden . So if you connect a USB cable to PC, you can use the small keyboard which is seen on the photo either with Pi or with Notebook PC...
Last edited by chileflora; Sep 17, 2019 at 12:05 PM.
Sep 17, 2019, 12:06 PM
Registered User
Here you can see the main joystick and behind, the power distribution module.

The main joystick has many functions:
First, it has control over three main axes (elevator, aileron, rudder).

It has also two buttons which momentarily switch the cameras on the airplane:
I have main flight camera, HD Runcam camera (HD), and optionally, rear view (RV) camera. So by pressing a button switch, I momentarily connect either HD Camera or rear view camera as a source feed for the VTx.

It has also a "SWAP" button, which swaps between main camera and the last selected camera (so I can alternate between Main-HD, or Main-Rear, leaving it permanently connected)

There is also the "TAKE CONTROL" (the main trigger). This button "degrades" by one step the automatization mode. If you fly in STAB mode, and press this button, the mode is switched to MAN. If you fly in AUTO mode, and need to make a small correction, you press the TAKE CONTROL and the mode will change to STAB. Once you release it, it goes back to the set AP Mode.

The joystick has also three "HATS", knobs which are like four position switches:
The upper black one (like a pyramid) (OSD) is used as three position switch for navigating OSD menu on the airplane (Pitlab OSD)
The white grey one (SCAN) selects one of the eight scan modes:
I have made scripts for automatically turning the main camera to different positions:
You have:
Ground Scan (camera looks down as far as possible, to left and right), there are three positions
Traffic Scan (camera sweeps from left to right and back rather quickly for trafic)
Ridge-Left: Camera sweeps between front view and side view rather quickly - very useful for skimming mountain ridges
Ridge-Right:
Final-Left: Camera sweeps between front view and side view, staying on the sideview just shortly and looking rather down, useful for
Final-Right: final turn on landing
Deep-Left
Deep-Right: Camera sweeps all the way to the side (and up for the view over the wing), then to intermediate position, then front

To cancel the scan, one can either move Pan/Tilt knob (on the throttle unit) or can press shortly a grey button (also one throttle unit). This grey knob has also a function to look momentarily left or right (turns main camera to a preset position to left or right).
Last edited by chileflora; Sep 17, 2019 at 12:27 PM.
Sep 17, 2019, 12:10 PM
Registered User
This is the most epic project ever! I was sure that you were going to -- at some point - just give up with the sheer scale of this. DIY Flight controller, DIY planes, DIY military-style mobile GCS. But no! It looks like you are getting close.

Looking forward to seeing the video of all of this in action.
Sep 17, 2019, 12:33 PM
Registered User
The "heart" of the system - Raspberry Pi with a small expansion board with I2C and Serial cables.

I2C is used for connecting I2C line which goes to an arduino Mega 2560 in white boxes inside the cabin - I call it the "Expander" because it allows to expand the number of buttons/pots

Serial Line is used for communication between the Raspberry Pi and the antenna unit
Sep 17, 2019, 12:39 PM
Registered User
The Antenna Unit...
The white box is another arduino 2560 which is responsible for all the functions of the Antenna unit:
-Signal Source switching (it can be either Ground Station Control, External Radio Contol, or Internal Failsafe Data)
- DL TX control (power off/on though a relay), bind button and power up power down buttons (the latter three hacked, i.e. with cables soldered and taken to Arduino pin to simulate presses)
- Receiving a SBUS signal from the local DL RX (as relay)
- Sending the SBUS signal to main DL TX
- Video swiching of the 4 Video RXs
- Reading RSSI levels, basically, of the 2 higher gain antennas (Dish 30 dBm and Patch 21 dBm), and of the local external DL TX
Sep 17, 2019, 12:45 PM
Registered User
Quote:
Originally Posted by Marc Dornan
This is the most epic project ever! I was sure that you were going to -- at some point - just give up with the sheer scale of this. DIY Flight controller, DIY planes, DIY military-style mobile GCS. But no! It looks like you are getting close.

Looking forward to seeing the video of all of this in action.
If I knew how much time that would require, I possibly would not have started this project...
And pricewise, it is not very cheap either, probably about 2000 USD (just for the cabin, the tripod/antennas excluded).

But if you think about it, an airplane which is capable of flying 100 km away (and back) and 12 km high (and down) deserves corresponding groundstation.

PS: The ranges, both horizontal and vertical, are theoretical ranges for MTD setup and do not necessarily imply that they were reached.
Last edited by chileflora; Sep 17, 2019 at 12:51 PM.
Sep 17, 2019, 05:23 PM
Registered User
I forgot to show the monitors, now there are three of them, the Main Monitor behind, 22 inches, Aux monitor above, 7 inches, Secondary Monitor to the right, 19 inches.
Also, sitting on the bucket was really not so comfortable experience, so today I made a base for the whole groundstation/seat... Next flight will be much easier.
Sep 17, 2019, 05:28 PM
hey whats burning?
metalbender4by's Avatar
Quote:
Originally Posted by chileflora
The Antenna Unit...
The white box is another arduino 2560 which is responsible for all the functions of the Antenna unit:
-Signal Source switching (it can be either Ground Station Control, External Radio Contol, or Internal Failsafe Data)
- DL TX control (power off/on though a relay), bind button and power up power down buttons (the latter three hacked, i.e. with cables soldered and taken to Arduino pin to simulate presses)
- Receiving a SBUS signal from the local DL RX (as relay)
- Sending the SBUS signal to main DL TX
- Video swiching of the 4 Video RXs
- Reading RSSI levels, basically, of the 2 higher gain antennas (Dish 30 dBm and Patch 21 dBm), and of the local external DL TX
Great job. Your passion for the hobby shows in your efforts. I am happy for you, I hope you get to enjoy it for a long time.

That being said, with all the systems you have put in place do you feel any latency it the controls? Is there any noticeable effects, other than what you mentioned on the joystick. With airplanes its not to much of an issue but could be a little unsettling if it was really noticeable.
Sep 17, 2019, 05:39 PM
Registered User
There are two latencies, the joystick to airplane latency, and camera to groundstation monitor latency.

Frankly, I do not care about latency, and I always had the largest range setting with DL, so the update rate was about 6 times per second = 180 mS. When on ground, you move sticks, and the control surfaces would jerk up and down, but in the air (unless yu do acrobacies), that does not matter.

Well to my system latency:
GS to Airplane: Groundstation reads inputs (joystick/buttons) within 1-2 mS; then GS sends data to Antenna unit through modem at 38400 baud 20 times a second (50 mS). The sending process takes around 10 mS. Then, antenna unit receives it, usually within 10-15 mS, but in extreme cases could go slightly more, and sends to DL TX. So, overall, the total latency is around 75- 85 mS., but definitively below 100 mS.

I could reduce this somewhat more, probably down to 50 mS overall, but not much lower.

There is a definitive latency with HDMI; I have an RCA to HDMI converter which preserves the 4:3 ratio, but it introduces some latency, I have not measured it, but it is considerable, probably in the range of 100 mS (I eyeball it at 80-150 mS). Direct RCA has almost no latency, but it stretches the image.

In the HDMI mode I would say there was some "strange" feeling initially, but only when flying in direct, manual mode. After half an hour of flight one gets used to it. In a sense it gives the airplane a more "realistic" feeling, it does not react as fast, you have to anticipate it a little bit. But unless you plan to do some dogfights with eagles, the overall latency and its impact on flight safety is irrelevant.
Last edited by chileflora; Sep 17, 2019 at 05:50 PM.
Sep 18, 2019, 08:20 AM
hey whats burning?
metalbender4by's Avatar
That is all what I expected to hear, and I agree for the long flights there probably is very little impact on how you would fly. I guess the only time it would be an issue is when you return to land and then you have the other controller. Great fun.

Mike


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