Good day and welcome back to TMac FPV! If you're fairly new to FPV or
coming from using a transmitter with a different system firmware, you may be
unfamiliar with OpenTX and right now might be a little uncomfortable using it.
I completely understand that feeling! Today, I'm going to clear things up by
going over only the OpenTX basics you'll need to know for setting up your FPV drone
or quadcopter. This will include the general concept of
information flow within OpenTX. By understanding this general concept, it'll
make it much easier for you to set up your model in your transmitter to
perform exactly how you want. I'll also use a couple specific examples to
demonstrate this concept of information flow using my Jumper T16 however, the
stuff we're going over today applies to any transmitter running the OpenTX
firmware. If you're ready to clarify your understanding of OpenTX and make it
easier for you to set up your quad, make sure to give this video a thumbs up
below, share it with your friends, and subscribe to YOUR TMac FPV channel -
your home for your "Journey to Better" FPV fun, flights and racing stuff! So you've
got yourself a Jumper T16 transmitter with OpenTX system firmware on it. If
you have one without Open TX, or you'd like to update your OpenTX version, I
encourage you to check out this video at the card in the upper right or at the
link in the video description below for how to do that. But what exactly is OpenTX?
Well, it's a highly flexible, feature-packed
open source firmware for RC models of many types - not just FPV drones or quadcopters.
Because it's designed with that flexibility and all those features
for many types of RC models, it has 11 different model menus which you can see
here! It's sort of like candy. Candy's good and so's the flexibility and all
those features within OpenTX. But if you try to eat a bunch of candy all at once
you might get sick. In our case, for FPV quads, we may get information overload. We
don't really need to use all those features for our FPV quad. In fact, we really
only need to use five of them - those being Model Setup, Inputs, Mixes, Outputs
and Telemetry (if we're even using a full telemetry receiver such as the jumper
R1 or FrSky R-XSR or a similar telemetry receiver). I've got product links in the
description below for both the R1 and the R-XSR. If you've never heard of the
Jumper R1, go ahead and take a look at this video through the card above or the
link below. I'll go over each of these five menus today and I'll start with
Model Setup and telemetry because those are very simple and we can get those out
of the way quickly. Then, we'll get into Inputs, Mixes,
and Outputs which form the basis of OpenTX information flow. I'll explain the
concept behind how these work together so when you're armed with this
information flow concept, you'll be able to implement some really cool things
with your quad in the not-too-distant future all on your own! As you can see,
we've already streamlined the use of OpenTX for a model setup from eleven
menu items down to five. Now we're just gonna eat some of this candy a couple
pieces at a time . . . we can always go back for more! First, we'll look at the Model
Setup menu. Here there's really only four things we need to do, if that - input a
model name, use a model image (not necessary but it's an available feature
and sort of cool) - and if you want some help on how to do that check out my
video on Jumper T16 custom images - then you can either scroll up to get to the
last page or scroll way down to the section on either internal RF or
external RF. For our demonstration purposes I'll use internal RF. Here's
where we set our failsafe mode to "no pulses," select our mode for our receiver.
If you're using either the Jumper R1 or the FrSky R-XSR you want to
select FrSky D16. You'll also want to select your channel range, normally 1
through 16, and set your receiver number for your quad. Here I'm using 2 since
it's the second receiver I'm binding. Then you just click on bind and the
transmitter will begin beeping. This is when you hold down the bind button on
your receiver while at the same time plugging the battery into your quad. It
takes a little bit of talent but you'll get the hang of it. I've got other micro
FPV quadcopter build videos which show this binding process if you're
interested, or better yet, check out our Fast Track FPV Course at TMacFPV.com
which goes over (among many other things) the entire processes for setting up
both your transmitter with OpenTX and your quadcopter with Betaflight in a
simple, step-by-step, logical approach. That's it! We're done with our first menu
in OpenTX! That wasn't so bad. Next, we'll go to our Telemetry menu. After
we've bound our receiver to our quadcopter, there's really only two steps
we need to take here. Scroll down to "Discover New Sensors" and
press ENTER. Once the sensor data has been populated, if you're using a full
telemetry receiver, just click on "Stop Discovery." Two OpenTX menus down and only
3 to go. The last three menus form the basis of our OpenTX information flow.
They are Inputs, Mixes and Outputs. Within OpenTX, the information flows from
various sources which can be your transmitter sticks that you use to
control your quadcopter, switches (either the many physical switches, sliders and
knobs your transmitter has or logical switches), or any of the telemetry values
which you just saw populated from your receiver. Within the Inputs menu, you can
modify the values of these sources. The first four Inputs lines are used as your
stick controls. Usually the only other Input line normally created for FPV
quads is using a telemetry value as your source - that being RSSI. We'll take a look
at two examples of Inputs here shortly, one for modifying the value of your
throttle stick using a curve and the other using that RSSI telemetry
value I just talked about. The information contained in these Inputs
lines can then be passed to your Mixes menu which is used to map your sources
to receiver channels for output. The sources for your Mixes menu can be
inputs lines from your Inputs menu or they can also be switches and these
various other things. Normally I use the Mixes menu to assign transmitter
switches to receiver channels to activate different things in Betaflight.
We'll take a look at two examples within our Mixes menu, one for assigning a
switch and the other for using the input line established for RSSI. Once your
sources have been mapped to receiver channels in your Mixes menu, that
information is then passed to the outputs in your Outputs menu. In your
Outputs menu is where you'll set your channel center, minimums, and maximums in
conjunction with Betaflight for your sticks' travel. In general, here is where
your outputs channels receive the information passed on from your Mixes
and converts that information to electrical pulses which are then
transmitted to your quadcopter's receiver. So, basically that's the concept of how
information flows within OpenTX and how these three menus work together. Now that
you have this overview, let's take a look at a couple quick examples for each of
these menus. In our first example for our Inputs menu, we'll be using our throttle
as our source for our input and we'll modify it with a curve. I won't be
getting into how to set up the curve, for that you can check out this video. It's a
very simple process, you just go to the input line you want to create or modify,
press and hold Enter, press edit. Our source is throttle. Here you can see
we've got a one-to-one linear relationship between our stick movement
and our quadcopter's response to the throttle. I'm going to modify that
using a custom curve. I've already created that curve as I mentioned
earlier. The reason I did that was to get better throttle resolution at a
certain altitude range which helps me to maintain my altitude in that range. It's
not necessary to use the throttle curve, and I'd say most people don't, I'm just
showing you this for demonstration purposes and how you can modify a source -
in this case your throttle stick - with the Inputs menu. So, I'll insert the
custom curve now and you see our quadcopter's response to our throttle
stick as our source in the inputs menu is no longer linear. That's how you can
modify the value of a source within your Inputs menu which can then be mapped to
a receiver channel using the next Mixes menu as we described earlier. For our
next Inputs example, I'll use a telemetry value as our source, specifically the
RSSI value. Since we've already "discovered sensors" earlier we have RSSI
as an available source. To create an input line, we just go to an empty line
and press Enter.
Insert an input name. I'm going to call this RSI. Then, for our Input source, we
find RSSI from within our telemetry values. There we're on telemetry now. We
want RSSI, we don't want plus or minus, we just want RSSI. There it is. You do
have minus and plus, we want just regular RSSI. Now you see here we have 0 dB,
our scale set to 0 dB. We want to change our scale to 100 dB so the range for RSSI
is 0 to 100. Then we just hit return to exit out. Here you see we've got
our RSI named input line using RSSI as our telemetry source which can now be
passed on to our Mixes menu. Now we go to our Mixes menu and for our first example
here we'll use the RSI input line we just created as our mixes source
and assign it to a receiver channel. We do that in the same way we just created
the line within our Inputs menu except here we're actually placing it on a
receiver channel not just an empty line. In this case, I'll be using channel 12
which is what I always use out of force of habit. We push the enter button and use
the scroll wheel in the same manner we did earlier to navigate our screen. So I
just go to channel 12, press enter, click on edit, and input this information over
here for our RSSI mix. Since all of our mix ranges are from minus 100% to 100%,
we need to change our weight (or rate as some people refer to it) to 200% and our
offset to minus 100%. That will take our 0 to 100 dB range we had on our Inputs
menu and convert it to our mix range scale. Then we just press return to exit
out and we've got our RSSI telemetry value assigned to our receiver
channel 12 which can now be passed on to our Outputs. For our next (and last)
example on our Mixes menu, we'll assign a channel to a switch for use as our
arming switch. You can assign a lot of switches to a bunch of channels to
perform various functions as you've seen I've done here. The process is the same
for each you're just using a different channel. So I'm only going to demonstrate
this for one switch. This isn't everything you need to do for switch
activation as there's still stuff to do in Betaflight but that's beyond the
scope of this video. To show you how simple the process is to assign one of
these channels to a switch, I'm going to go to channel 5 and create my arming
switch. So, I'm going to scroll down, press enter, name it. I'm going to name it "ARM"
for arming. Then for our source, click enter, and when it's flashing you can
pick whichever switch you want to accomplish whatever function that you're
trying to program. In this case, I'm creating an arming switch and I always
use the same switch for arming which is this green one down here. So in order to
get that switch here, all I need to do is flip it.
Switch F, press return, press return, exit out. Now on channel 5 I've got switch
F which is my arming switch for my quadcopter. That's it! Now we're at the end of
our OpenTX information flow with the Outputs menu. Remember I said earlier,
here is where the information from our Mixes gets transformed into electrical
pulses which are then transmitted to your quadcopter's receiver. What we want
to make sure to do here is set up our center point, minimum, and maximum end
points correctly. We can do that by going to the "Receiver Tab in Betaflight,
with props OFF our quadcopter, having it plugged into our computer with both the
LiPO connected, and our transmitter on. Then we just observe the center, minimum
and maximum values at center, min, and max stick deflection for each axis. The
center should be 1500, the minimum should be 1000 and the maximum should be 2000.
If any of those values are not the correct value, we just click on the
appropriate entry for that channel and use the scroll wheel to adjust the value
in our transmitter until we obtain the correct value in Betaflight. Most of the
time the value is going to be between 97.5 and 97.9
positive and negative. To adjust the minimum, we hold the stick to
its minimum deflection and use the scroll wheel to change the value. Here
you can see in Betaflight the value is going down to 994. We want
it set at one thousand. So we use our scroll wheel to get it to one thousand
and at that point we click the enter key. Now we've got it set to one thousand.
We do the same for our maximum value. We deflect our stick to its maximum
deflection and change this number until we get to the maximum stick deflection
of 2000. Now I'm using the terminology 1000, 1500, and 2000, whereas
on this transmitter screen you're seeing values in the 90s and 100's. These
values are in percent of stick travel, whereas in Betaflight, these values
correspond to microseconds of the pulse. Once all that information gets
transferred into electrical pulses of the proper durations, its then
transmitted to your quadcopter's receiver which takes it from there. Pretty amazing
stuff! So, that's the basics of OpenTX for FPV quads using our Jumper T16
transmitter. Remember, these things apply to any transmitter using OpenTX
firmware. Although OpenTX is feature packed, I've
shown you don't need to start with everything all at once. You can start
with these 5 menus and progress with more advanced features later.
I've also demonstrated for you the concept of information flow in OpenTX
between Inputs, Mixes and Outputs. With this understanding, I hope I've
eliminated some of the mysteries surrounding OpenTX and increased your
confidence in using it on your own to configure some fun stuff with your quad
for some outstanding fpv adventures. If you found this video useful give it a
"thumbs up" below, make sure to share it with your friends and spread the word,
and subscribe to your TMac FPV channel! Let me know your thoughts on
OpenTX in the comments below. Thanks for your time. I'll see you next video.
Clear skies friend!