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Electric Stunt => New electronic technology => Topic started by: Wolfgang Nieuwkamp on February 19, 2024, 10:13:29 AM
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Recently I developed a timer with the SEEED Xiao nRF52840 Sense.
Reason. It incorporates acceleration/gyro sensors, so no additional electronics are needed. Originally, I incorporated a start button on the printed circuit-
Since he Sense version also has a tiny Bluetooth antenna, I checked the range when you contact it with an iPhone.
There is a simple Bluetooth app for iPhone. Lightblue (also for Android). at 21 meter distance, no problem.
Starting by Bluetooth is allowed by the FAI, since it uses the 2,4 Ghz band.
I only use it to start, as soon as the signal is given, the connection is disabled.
Comments welcome,
Wolfgang
(https://myalbum.com/photo/oUzE9pAwWSRh/540.jpg)
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Nice. More details please.
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Hello Christ,
the timer is programmed with Arduino. After pressing DONE on the iPhone there is a 10 seconds delay, to put the iPhone in your pocket. Then the timer starts regulating the motor, trying to keep the line pull at 3g. Only the acceleration sensors are used.
That regulating system has one drawback: Flying horizontally downwind, the motor speed would become very low, and the airspeed would be too low. To solve this, during horizontal flight the minimum pulse duration is set higher.
Please note that the only setting is the desired line pull. The propeller should be chosen, so that at maximum load the ESC is not overloaded.
Adjustment for line length and lap time is done automatically.
If you want to try the system. I can build one for you.
Best regards,
Wolfgang
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Wolfgang,
Can the system also be setup to stop the flight on demand? This would be great added safety feature for those that fly alone or just do short trim flights.
Also, what ESC's does it work with?
Best, DennisT
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Dennis,
sorry for the late answer.
The system can only start, so no stooge is needed when flying alone. After the start pulse, the bluetooth connection stops.
It works wit any ESC. The program is written in Arduino, so it can always be adapted if needed.
Regards.
Wolfgang
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Two thumbs up Wolfgang. I have been looking at the SEED microcontrollers myself but I haven't been working on my timer software for over a year now.
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Hello Mark,
if you do not like soldering. I can send you a spare one. At the moment it has 3 options:
- Standard flight, 330 seconds
- Test flight, 60 seconds
- Demo mode, for bench test
Regards,
Wolfgang
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Hello Mark,
if you do not like soldering. I can send you a spare one. At the moment it has 3 options:
- Standard flight, 330 seconds
- Test flight, 60 seconds
- Demo mode, for bench test
Regards,
Wolfgang
I can solder ok. However, that doesn't imply I wouldn't be interested in giving you system a test run. I have a key fob based unit that works on the bench but haven't yet incorporated into a flying timer. With 4 buttons on the fob there are lots of conceptual things one could do in terms of trimming. A phone app could work but reading the phone could be a bit sketchy.
I sent you an email earlier.
Mark
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Wolfgang-
Wow! This is cool. The Climb and Dive Timer uses a uses a SEED Studio Blue Tooth device with a daughter board for the 6 DOF sensor and Power Supply. This new nRF SEED -Sense device could eliminate the extra board. Except may I ask how you handled the Power Supply? Its datasheet says all it's I/O pins are 3.3 volts yet it's going to get 5 volts from the USB programming connection, hmm. I've never set the BEC voltage on a speed control below 5. Will a 3.3 volt servo pulse be processed by the Speed Control? 2/3 VCC is...
I am versed in Arduino and am willing to give it a go if I can obtain the code. I'll keep it private, no commercial use.
Thank You Very Much for Your Innovation!
UPDATE 6-24-24 : I studied the datasheet for the Seed XIAO nRF52840 Sense device : not only does it have the 6 DOF sensor, it has microphone! Ponder this : "Motor Arm!" <prop makes a few revolutions> "Motor Start" <motor accelerates to full throttle and flight commences>. Controlling with your phone, OK. Controlling with your voice, Better...maybe...maybe not (?)
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Starting by Bluetooth is allowed by the FAI, since it uses the 2,4 Ghz band.
I have been working on something similar but I was concerned that the rules prevented the use of 2.4Ghz during competitions. My intention is to build a timer with remote on/off, so that I can take off from the ground without assistance but also stop the flight if necessary.
Would FAI and AMA approve this?
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FAI allows remote emergency cut off, but should not be used for planing landing position, or replace other safety rules.
However such thing exists, also as an stand alone C/L timer, also like a remote throttle (for cathegories where it is allowed) or as an hook up device between active timer and ESC for emergency cut off in F2B.
https://www.youtube.com/watch?v=52Jo_iNp3KE
https://www.youtube.com/watch?v=HZTShdWivI8
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FAI allows remote emergency cut off, but should not be used for planing landing position, or replace other safety rules.
However such thing exists, also as an stand alone C/L timer, also like a remote throttle (for cathegories where it is allowed) or as an hook up device between active timer and ESC for emergency cut off in F2B.
https://www.youtube.com/watch?v=52Jo_iNp3KE
https://www.youtube.com/watch?v=HZTShdWivI8
I am asking because i have been working on this for a while
https://www.youtube.com/watch?v=9SlP_G8Uiko (https://www.youtube.com/watch?v=9SlP_G8Uiko)
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That handle can be useful for scale, carrier or some sport models, but I cannot imagine having such thing in stunt circle, so it does not matter if F2B allows it or not, better to check if scale and carrier allow 2.4 throttle. It will also depend on country, for example our Slovak rules limit stranmission only by wires and band is limited to few kHz, means you cannot trick it by pushing 2.4 from anthena to lines and tell "it is by wires" ... you really need insulated lines and correctly transfer it galvanically.
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That handle can be useful for scale, carrier or some sport models, but I cannot imagine having such thing in stunt circle, so it does not matter if F2B allows it or not, better to check if scale and carrier allow 2.4 throttle. It will also depend on country, for example our Slovak rules limit stranmission only by wires and band is limited to few kHz, means you cannot trick it by pushing 2.4 from anthena to lines and tell "it is by wires" ... you really need insulated lines and correctly transfer it galvanically.
Yes, this handle is for scale and carrier pilots, i was just asking for ideas. thanks!
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Wolfgang,
Would be great to add the on-demand shut down feature as it would add additional safety to flying alone (there have been times when people have just walked into the circle and being able to shut down would be a big plus). Also, would allow some older folks (and beginners) to fly as long as they feel comfortable and shut down before getting in trouble.
Best, DennisT
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I saw a demonstration of using a cell phone and Bluetooth to program a CL stunt plane. It worked very well.
In an emergency all you need to do is drop the handle. Dig out your cell phone. Open the app. And shut down the engine. This could work if it's not blinding sunny and there's nothing of value within a half mile and the plane isn't out of range before you order the shutdown.
Routine programming, good.
Emergency use, not too good.
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A cell phone or remote transmitter is not the only way to initiate an emergency shutdown. It is possible to program the accelerometer in the timer with a form of gesture recognition to detect when the pilot gives a pull on the handle. I have this feature slated for the next code release for the Climb_and_Dive timer in the Spring. 3 consecutive pulls on the handle will stop the motor. I've had some beta testers check it out but I want to make some more improvements before the official release. (We've had a lot of snow lately, it feels like it might be June before the flying circle reappears)
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A cell phone or remote transmitter is not the only way to initiate an emergency shutdown. It is possible to program the accelerometer in the timer with a form of gesture recognition to detect when the pilot gives a pull on the handle. I have this feature slated for the next code release for the Climb_and_Dive timer in the Spring. 3 consecutive pulls on the handle will stop the motor. I've had some beta testers check it out but I want to make some more improvements before the official release. (We've had a lot of snow lately, it feels like it might be June before the flying circle reappears)
I am assuming that you went to 3 to avoid a shutdown from hitting wake turbulence. This is a good idea. Hope it works.
Ken