new transmitter design

[Bruce Dillon]

Hi All

My thoughts on what the next generation of Chinese radios should
have.

They need to have expo because as far as I know all the cheapo radios
at the moment have dual rates but not expo. Please correct me if am
wrong about this. I try to study the manuals of the Chinese radios,
but they just give me a headache.
The current crop seem to be designed with mainly helicopters in mind.

I am not sure about having a "automatic model-memory select".
I guess that you would have to arm the model first?
This is a potentially dangerous situation with an electric model.
Especially with a Suppo speed controller.
Also some speedies will not arm and then lock you out if they don't
see a throttle signal in a very short period of time.
I think the model match system used by spectrum would be a safer way
to go.

Being able to flash the firmware of the radio would be great, I have
never forgiven spectrum for the buggy firmware in the DX6i.

Bye

Bruce



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[RobC]

RadioLink already do a 6 channel 6 memory set, based on the later FF6
in everything but the throttle-cut button. D/R, Expo ATV, switchable
mixing, flaperon, elevon, the works (in a small way!). The trouble is
there are three major points that let it down - the cheapo finish, the
lack of a failsafe and the single aerial design. Model match might be
nice, but not having used it, as long as the model name is displayed
on the transmitter I can manage ok.
I agree with Bruce that the module market will be short lived, after
all, those who want to convert will buy one or maybe two modules and
that's it. A lot of existing set owners will opt to stay on
35/36/72MHz or whatever as the band becomes less crowded, and
newcomers will buy straight into dedicated 2.4 sets. The big worry
for those of us who have converted is - will our modular 2.4 sets be
supported and receivers available in years to come? If the Chinese
companies go for high resolution dedicated systems, will we be left
out in the cold? I've got perfectly servicable FM receivers that are
10 or more years old. Will I be able to keep using my FrSky
conversion for 10 or 15 years?

Bob

[sasa]

I would add posibility to configure transmiter via PC. Like this is
made for FBL units.
Sometimes it is complicated to configure new heli and to not forget
some settings to be made.
Small PC aplication could help newbies doing that. Plus users can
share setting files and help each other improve their configuration.
Rtf models could be preprogramed OOTB easily.
Just my 2 cents

[JelleB]

Hello all,

My take on a next Chinese radio design is that it needs to be as open
as possible. The big brands all play a game of lock-in and cornering
their market, I don't like that and don't think it has to be that
way.
Right now the only recent radio I know of that is somewhat open for
tinkerers is the Turnigy 9X. You will need to solder on your own ISP
connector and buy a programmer, but after that it is fairly
straightforward if you know what you are doing. The Arduino platform
for programming has taken a big flight and this transmitter is
basically a big arduino in a specialized case with a nice LCD, push
buttons etc.
I think the stock firmware on the 9X stinks, I have had this
transmitter for over a year, and I still don't know how to use each
switch. But there are already 3 different projects on the way to
create a alternative firmware for it, one that does not restrict you
for the sake of simplicity or because others do it too.
So, if Turnigy (or any other cheap transmitter maker) listens: create
your next version with a real programming interface, preferably USB
(newer AVRs have a usb interface), but ISP will do too. Put it out
with a basic firmware, that does most things out of the box. Publish
the schema and make sure the barrier to hacking it is low. Welcome
everyone that wishes to modify their set (hardware and software) and
create a functional community for it. Make sure there is a good
bootloader on the chip that prevents bricking or enables easy recovery
if things work out wrong.
Only a slight minority will be able to create new features/firmware.
That is no problem, as long as you get the able ones on board. Leave
it to your users to decide what extra features they really want/need.
As for the hardware:
* Auto shutdown would be nice. Too many times have I discovered a low
battery when I wanted to fly.
An ability to use Lipo batteries (2s or 3s) would be nice too, that
way you can swap for a flight battery when you really wish to fly.
With the feature above that would hopefully never happen.
* A modular transceiver part. The part that does the actual
transmitting should be separate, so you can swap in a more capable
unit at a later date.
* Different methods/protocols to interface to said transceiver module.
Right now the standard is ancient ppm signal. It suffices, but I2C
would be much better and allow for two way communication between the
radio(interface), transceiver and the model.
* A method to interface external inputs to it, like VR-glasses with
gyros, or anything else that has not yet been invented. Most AVRs have
at least one I2C interface that would be suitable, but some analog
inputs would be nice too.
* A graphical LCD screen is a standard, but I don't need to fancy a
thing for that. When a video downlink becomes feasible, it would be
nice to have it inside the transmitter, so a high resolution one would
be nice, but there is no immediate need for that I think.

Software:
* Set-up wizards: just a list of questions that asks what kind of
plane you have, where the servos are and what is up for each servo.
Right now you have to actively know how to setup your radio, and it
takes quite some trial and error. With a graphical interface, it could/
should be much more easy.
* Flexible 'programming' underneath. Each button should be able to
control each channel if the users wants so. The wizard will select a
commonly used layout, but the user should be able to change this
layout to suit his specific wishes. The wizard covers most cases, for
more specialized things the user should (be willing to) dig deeper. In
practice this might mean some intermediate 'registers' that the user/
wizard can connect to each other to create the desired mixing.
Sequences that can be programmed, like a gear servo to moves out
slowly, or a transition mixer for VTOLs, or anything that requires a
specific sequence for controls and mixes.
* Communication with the transceiver or the model when selecting a
model. Prevent flying with the wrong model by either binding each
receiver to their own binding code, or use some other trick to verify
that when you have selected model A, model B will not respond (or
signal an error). That will save you some planes/embarrassment.
* Have two way communication between the model and the radio
(telemetry). A slow serial link would suffice for most applications.
Extra hardware could be sold like GPS, vario-, alti-, speedo-,
thermo-, or voltage meters that you connect to the receiver. The radio
software should be able to decode their signal and react to it, like
short beeps (two tones) with a variometer, and display/alarms for most
other things.
* A downlink for real-time video signal would be very nice too, but as
it stands the technology is not good enough yet to get a reliable
downlink to control your aircraft from. Any solution for this would
need to address more systems in the air all competing for bandwidth.
Ad-hoc flying mesh networks anyone? ;)
* As for the actual transceiver link: a system that would be hackable
to would be very nice. On the model side it would need a programmable
fail-safe at least, so a temporary glitch would not deploy the safety
parachute, but a 3-second blackout will.

So there you have it, my laundry list for rc-transceivers!

Kind regards,
Jelle