Newbie Drone build help needed

[wafflejock]

I don't fully getb the TX, RX SDA, CLK, SCL things. Think the TX and RX is the signals, the numbers next to these the UART numbers, CLK and SDA might be the compass...SCL...is that the same as CLK? Confusing. Anyway, I need help! Thanks in advance!

Again haven't hooked up gps but I can shed light on some of those abbreviations.

TX = transmit signals come out of this port
RX = receive, expects a signal to come into this port (usually hooked to tx or some other device)

Basically one TX/RX pair makes for two way "duplex" (simultaneous) communication. Typically these are considered a UART

SDA = Serial data
SCL/CLK = Clock a pulse or shared clock beat between devices this way baud rate basically doesn't need to be known up front and one oscillator/clock signal is shared between devices

Believe SDA/SCL is usually for I2C or "I squared C" bus, two wire communication between a chain of devices. Usually any device on the I2C will have some predefined address so many devices can share the same SDA and SCL connections for synched clock and data and the addresses allow devices to respond to data only relevant to them.

I think you only need one or the other (I2C or UART) generally but might be the case that GPS module uses one protocol and the compass uses another or some other redundancy but just guessing.

One thing that is confusing is generally want a TX going to a RX and an RX going to a TX when using UART connections.

 

[Christ1@n]

I've done my best trying to get the GPS to work but it don't. It semms hopeless, but I really want this working. The main issue here seems to be betaflight says no sats or other signals and the icon in the top bar doesen't light up, as I think it should. I feel I've really now got the hang of where the wires needs to go. I've even opened up the GPS to confirm the cable markeing on the internal GPS boards. The RX/TX is switched as it should and I've even tried to move the voltage wire to a 5v connector instead of as 3v as I heard somewhere it might need 3.3v and I can't find an output like that except in the big cable plug connector next to the USB. But the voltage shift didn't help either (think the GPS has a voltage regulator, so 5v should be ok). Maybe it's Betaflight itself that is the problem. Is there any other app I can use to test the GPS signals? Any suggestions are very welcome at this point. Please see the attached pic. To the right is the connection guidence from the GPS manual, to the left is how it currently wired to my FCB and on top an image of the status bar in betaflight. I've tried different UART settings and checked every place I could find i betaflight that has GPS settings or info, but nothing helps. This is really puzzling! What am I doing wrong?

 

[Dugdog47]

Try flashing the inav firmware to your fc it's more suited to gps.

 

[Christ1@n]

Try flashing the inav firmware to your fc it's more suited to gps.

Hmmm, ok. This page says my boards it's supported. https://github.com/iNavFlight/inav/wiki/Supported-boards
Should mean I can just downlaod the iNav Configurator and start configurating/see if the GPS works there, right? Or am I missing steps?

Still open to other options if anyone else has an idea.

 

[Dugdog47]

No you'll have to follow all the steps on flashing your firmware, just follow the steps on the flash page and there many youtube videos on how to do it.

 

[wafflejock]

Yah like @Dugdog47 says you'll need to flash the FC with the firmware first that gets the base of the new software on there (also called firmware since it's written or flashed onto the flash memory on the chip on FC). Basically just need to hook up the board over USB and open the configurator then go over to Flashing mode instead of connecting (this is how it works in betaflight pretty sure same in iNav though).

Depending on the FC you may need to short some pins or hold a button while powering up to get it into bootloader/DFU (device firmware update) mode, most of the newer stuff you can just hit the flash button and it can reboot the MCU/chip on the FC and get it into firmware flashing mode without needing to short any pins (connecting signal to GND typically) on boot. If just hitting the flash button (after picking your FC from a list) doesn't work then I go to looking for a boot button or pins and try to hold that button or short those pins while giving the FC power (then let go) so it's ready to accept new firmware.

After the firmware is flashed then you can "connect" and get into the configuration tabs again.

 

[wafflejock]

Hmmm, ok. This page says my boards it's supported. https://github.com/iNavFlight/inav/wiki/Supported-boards
Should mean I can just downlaod the iNav Configurator and start configurating/see if the GPS works there, right? Or am I missing steps?

Still open to other options if anyone else has an idea.

Also I plan to watch through this when trying to get it setup myself, just jumped around and found where he starts messing with betaflight settings:

 

[Christ1@n]

Solved it! As I was as sure as I could be that I've connected the GPS correctly I concluded the problem had to be Betaflight, not the app itself as it supports GPS, but the settings. Thanks from the video above I figured out that the Protocol for the GPS needs to be set to UBLOX, which isn't the default. Not sure why this didn't become clear to me before, but that was it. Probably sticking with Betaflight for now to push on to finish my build, might switch later if I feel it's needed. Thanks for you continued support.

 

[wafflejock]

Solved it! As I was as sure as I could be that I've connected the GPS correctly I concluded the problem had to be Betaflight, not the app itself as it supports GPS, but the settings. Thanks from the video above I figured out that the Protocol for the GPS needs to be set to UBLOX, which isn't the default. Not sure why this didn't become clear to me before, but that was it. Probably sticking with Betaflight for now to push on to finish my build, might switch later if I feel it's needed. Thanks for you continued support.

Sweet! thanks for posting back and being the guinea pig curious to know how it works out in practice too let us know.

 

[Christ1@n]

Sweet! thanks for posting back and being the guinea pig curious to know how it works out in practice too let us know.

Thanks! Sure will. Just waiting for the serove cable to arrive in the mail to get going with setting up the receiver. Anyhting to think about regarding that bit?

 

[wafflejock]

No major gotchas just want to be sure signal going into correct pin for receiver. Some may have inverted signal, that's the only weirdness I've heard of but not experienced, otherwise in Ports tab select correct UART with the serial RX toggle and then in Config tab select the correct protocol for receiver, if those two are correct you'll see values moving in receiver tab, if they are mapped wrong change the "channel map" setting on the receiver tab.

 

[Christ1@n]

Progress!! Got the servo cable in the mail today, so now the receiver is connected and it all seems to be working. Was able to control the little drone thing in Betaflight. What do I do next? Where do one start in terms of configuring, programming, mapping etc. now that all the components are in place and hopefully wokring? One thing I've been wondering about, how do I know the FCB in monted the right way? I don't see an arrow or similar symbol on my Omnibus F4 V5. Any other clever way for a newbie to figure this our? Also, I'm don't know how to get the magnetometer to work in Betaflight, if at all possible? As always, any general tips and sugesstions are very welcome. Anyone know of any great generic guides or similar?

 

[wafflejock]

Progress!! Got the servo cable in the mail today, so now the receiver is connected and it all seems to be working. Was able to control the little drone thing in Betaflight. What do I do next? Where do one start in terms of configuring, programming, mapping etc. now that all the components are in place and hopefully wokring? One thing I've been wondering about, how do I know the FCB in monted the right way? I don't see an arrow or similar symbol on my Omnibus F4 V5. Any other clever way for a newbie to figure this our? Also, I'm don't know how to get the magnetometer to work in Betaflight, if at all possible? As always, any general tips and sugesstions are very welcome. Anyone know of any great generic guides or similar?

On the first tab in Betaflight after you hit connect you should see a 3D view of the quad that moves when you physically pick up and tilt the quad, if it moves in the virtual view the same as real life then your board is aligned correctly. Usually there is a small arrow somewhere on the board but can be hard to locate (or just not there).

 

[wafflejock]

If the alignment is wrong you can either reorient the board or easier just change the board orientation I think in the configuration tab (will double check here). "Joshua Bardwell" on YouTube has tons of walk throughs on Betaflight config too.

Basic steps:

Bind controller with rx
Setup serial rx in the "Ports" tab, save
Select the correct protocol in the configuration tab, save

Check receiver tab should see sticks moving correspond to motion of sliders on screen make sure goes from about 1000 to 2000 if range is wrong look up 'rxrange' to see how to fix that. If sticks are changing wrong values (throttle changes yaw etc.) swap TAER1234 values to get input to channel mapped correctly, AETR or TAER depending on transmitter config and receiver config. If changes made save.

Go to modes tab and setup arming mode switch (might require configuring transmitter for sending switch input to the receiver). Save.

With props off, plug in battery go to motors tab make sure all motors spin and spin correct direction. If reversed use blheli configurator to reverse or swap any two of the three motor wires.

If all the above checks out get props on bring to a field hook up the battery and try to arm. Use the right stick to pitch/roll slightly while sitting on the ground, make sure everything looks good, level it out give a little throttle and make sure it doesn't flip out . If you succeeded all will be well, likely though you will have to swap props around or have something else loose, be sure everything is taped down out of the way of props or zip tied down and can't bash into stuff and try again

 

[Christ1@n]

Thanks for this @wafflejock The receiver is fully connected and I THINK it works, going to look into the rest in the coming days. One quick thing on anopther topis. I have had a really hard time finding the right kind of props. Someone a while back mentioned I should probably go for cheap 8x45 props But I can't really find any god options. I did find there. Would it make any really big difference to go with these 7x42 props? Would they be ok options? https://www.getfpv.com/gemfan-flash-7042-durable-2-blade-ferrari-red-set-of-4.html

 

[wafflejock]

Yah I would guess will still work too that extra inch of disc area the prop makes when spinning just gives x percent more force from moving air, always good to check your configuration on ecalc.ch though just to be sure it will fly and not have really bad thrust to weight or flight times. I had to order the 1355 CF props I'm using on the big hexacopter from China and wait about a month for slow boat shipping.

 

[Christ1@n]

Update. Going pretty well. Drone arming, FCB axis configured, motors spinning the right way, motor and protocal configured etc. and I've ordered a bunch of props. One thing I can't quite get the hang of is the Failsafe settings in Betaflight. When I turn off the transmitter the motors keep spinning at whatever rate I had the throttle. Not sure what the hell is going on. I can find the tad with the settings etc. but I can't find an on/off button/switch for it on the Betaflight settings...very strange. It should just activate when the drone loses transmitter signal, right? I have however been able to configure failsafe in the the flysky settings.

This works, .i.e. when I turn the transmitter off the engines lower the engine to the lowest revs. Not sure how this relates with the configuration in betaflight, but I suspect these settings works together as it has to be the FCB that lowers the engine revs when I turn the transmitter off, the transmitter can't do that as it...off. It's important I get this wokring right as I intend to use fly to home, which is supported by the failsafe fallback plan in betaflight. Not sure how I can test the return to home without doing it for real. How can I be sure what doing what here? Anyone understands this as can explain how I can sort this?

 

[wafflejock]

Yah so there's at least two kinds of failsafe conditions I can think of:

1. Transmitter/controller loses it's link to the receiver, then the receiver failsafe kicks in.
2. Receiver on quad gets disconnected or otherwise stops sending valid signals to the Flight Controller.

I think what you did is 1. If you can program the receiver to send no pulses if no signal is received from the transmitter that makes both failsafe conditions effectively the same, the signal goes dead. Then you can just handle that version of the failsafe at the FC to have it do whatever is necessary to bail out "safely" at that point.

Regarding testing it out best way I think is go to a big empty field first make sure arm/disarm and normal cruise around is working fine then fly it out over a safe area where the failsafe should be able to trigger and test (think JB just did a vid on this like a few days ago too so probably worth checking, know he is doing iNav now but probably still relevant I think maybe shared code between iNav and Betaflight from Cleanflight core maybe or some other shared fork or something... interfaces seem pretty similar for the configurator at least)

 

[wafflejock]

Follow up on second thought you may want the first fail safe to do something different like just try to hold the current throttle and attitude or angle mode holding so in the case of momentary drop out the quad doesn't immediately go into return to home mode unless that is in fact what you want but this will take some coordinating between your receiver failsafe and betaflight depending on exact behavior you're going for and what is "acceptable" kind of failure.

 

[Jazzman]

Hey there guys, I just binged this thread in like half an hour, and OHMYGOD what a wild ride!!

You two @wafflejock @Dugdog47 seem like absolute fountains of knowledge and I by NO means want to hijack this thread, but posted a similar request for information/pointers with no replies, and I would love it if either of you had the time to give my first build compatability a quick review

New Member, build compatibility

@wafflejock So the build is gonna look alot more like this after some previous advice Frame: https://www.banggood.com/HSKRC-VO235-235mm-Wheelbase-5-Inch-4mm-Arm-Carbon-Fiber-Frame-Kit-for-RC-Drone-FPV-Racing-110g-p-1494640.html?akmClientCountry=AU&rmmds=cart_middle_products Motors...

quadcopterforum.com

@Christ1@n GOOD LUCK!! It seems like after basically a year you're getting super super close ^_^!! I am following this thread and wish you all the luck in the world, although, you seem to have things covered so far !!