Model Boat Mayhem
Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: C-3PO on February 20, 2019, 09:29:19 pm
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RCC - Radio Control Command
(https://modelboatmayhemimages.co.uk/images/2019/02/20/IMG_3032.png)
Exploring what's possible with a smart phone or tablet
Excluding the phone or tablet the cost less than £5 - range 200-400 meters (NB - Circuit switching and audio hardware at extra cost)
In theory unlimited switching ie not limited to x channels
https://youtu.be/tPqyDvSJtBg
C-3PO
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good idea,
:-))
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Hobby King sold a wifi enabled receiver a while ago... with an app similar in concept to what you display... i bought one, and it worked great on the bench, but i would say the range was more like 50 meters, not 400. allowed the boat to get halfway across the pond before it stopped dead in the water.
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I would not recommend this approach for the control of throttle or rudder on a model boat.
The low latency (data packets currently throttled at 100hz), direct access concept to “switching” things is the most attractive benefit of this approach rather than having to hold a stick in a certain position for so long or jab a stick x times to trigger an event e.g. light or sound or go the multi switch route. The visual interface makes life much easier - it is using 2 way communications so could also be displaying telemetry back from the model.
I will conduct some proper range tests in the next few weeks. I have not encountered the HobbyKing Wi-Fi receiver – a few initial observations that may affect it’s working range are:
- pcb antenna vs. external (a matched external antenna would likely double or triple the range)
- Wi-Fi devices are often set to balance range vs. power consumption – it is possible to override this by setting registers to get approx. 20 dBm output (similar output to most 2.4Ghz RC sets)
So the biggest limiting factor will be the smart phone/tablet Wi-Fi range – I have many things on my ideas list to throw at this subject. One idea yet to be implemented should give a guaranteed range of 500 meters and possibly up to 1.5km but will likely affect latency.
I am exploring the communications topic as part of my “Chasing the Bubble” submarine operating system which will use a novel method of 2 way comms – I am currently evaluating the underwater comms aspect and initial results are encouraging but not life changing.
For those that are interested – no software is loaded as such onto your device(phone/tablet) you simply connect to a WiFi access point (no router or internet involved) and navigate to a page in your devices browser.
I envisage a “template based” system that would allow anybody to configure the system to their own needs.
My goal is that the end user simply needs a text editor and the ability to save files to an SD card and this would then allow them to bring to life their own vision.
Appreciate that this won’t interest many – but if it sparks your interest it opens up an interesting concept of controlling accessories on your model for very little cost - (Wi-Fi access point Approx £5)
C-3PO _._
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"Chasing the Bubble " - RCC & Submarine UHF communication evaluation
I will be using an extension of the Radio Control Command concept to receive and display telemetry as part of the evaluation of my UHF submarine communication ideas.
The image below shows both the signal strength as received at the submarine (remote) and the shore (local) - this will allow me to monitor both the radio signal strength and the submarine depth
A few loose ends to tidy up and then testing will start...
(https://modelboatmayhemimages.co.uk/images/2019/03/13/2019-03-13_21-06-31.jpg)
C-3PO
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c-3po...
when you say "UHF", what specific frequencies are you thinking of using?
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c-3po...
when you say "UHF", what specific frequencies are you thinking of using?
458.500 - 459.500 MHz (Device capable 424-510Mhz)
C-3PO _._
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It occurred to me that there are pin compatible devices in the same family that may be put to use depending on local legislation re use of the ariwaves
315MHz Module 290-340 MHz
433MHz Module 424-510 MHz
868MHz Module 862-890 MHz
915MHz Module 890-1020 MHz
C-3PO
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in addition to frequency, there are also local limits on power output... i remember doing some testing for a guy in belgium... 433mhz instead of your 458, and a max of 10mw output.
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Is there any merit at looking at the model railway fraternity for inspiration or parts for this?
...There's folk in that community absolutely mad-keen on putting everything through arduino, smartphones and ipads. To be fair, they have some fairly well developed ideas also.
I can't think of much worse myself, coming home from work sat all day infront of a PC and then doing my hobby through a computer or smartphone. But I appreciate it suits many. I can't fault the effort involved though. Each to their own I guess!
Rich
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Next step - Depth Sensor Calibration - Analog vs. Digital sensor
(https://modelboatmayhemimages.co.uk/images/2019/03/17/CTB_Depth.jpg)
C-3PO
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Got a pretty good spread of frequencies to play with here in the Uk. I think the legal limit for the 458mhz band is about 0.5watt without a license.
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100mw effective radiated power (includes any antenna gain) on 458mhz. Having a license makes no difference in the UK as model control excluded from amateur radio licence
C-3PO -.-
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100mw effective radiated power (includes any antenna gain) on 458mhz. Having a license makes no difference in the UK as model control excluded from amateur radio licence
C-3PO -.-
That's ok I am a Amateur Radio User and License holder ;)
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That's ok I am a Amateur Radio User and License holder ;)
Hi Richard,
Is there a benefit from being a Amateur Radio User and License holder?
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Not like there used to be.
CB came then mobile phones
So every man and his dog goes around radiating
Ned
G6 RNK
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Not like there used to be.
CB came then mobile phones
So every man and his dog goes around radiating
Ned
G6 RNK
Well Put Ned
MM3KQI
73's