Just The Tip - Ep 05 - OpenTX / EdgeTX Secrets Revealed - Audible Low Battery Alerts!

Thanks for joining me for another episode of "Just The Tip", a series of short tech tips and tricks.
I find that I make these from time to time to help members in my fly-group or various chats, so I figured I'd better just put them all on KZbin so others in the hobby can benefit.
Today's tip is for my OpenTx / EdgeTx pilots who "forgot to setup their OSD"... You know who you are... :)
Do you just want an audible alert on low voltage conditions, or want to be able to quickly get an automated or manual real time voltage call out from their radio's speakers? This tip is for you!
I'm revealing some of my OpenTx secrets!! I like "convenience hacks" like these, and I think you guys will too!
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[@Itsmedazza]

cheers for the great setup help

[@sharangkirloskar]

Exactly what I was looking for! Thank you!!

[@Rogue_FPV]

Happy that it helped you!

[@Sam-gr8pl]

Yeah this Video is helpfull .. thanks

[@canix_fpv940]

Thank you so much great video. Got it setup on my mamba.

[@Rogue_FPV]

Awesome! Glad it helped you! 💯

[@CheeseFPV]

Great video as always bro!!!

[@Rogue_FPV]

Thank You!!! Appreciate Your Support!!

[@CheeseFPV]

@@Rogue_FPV appreciate all the info videos 😁

[@DrFrantic77]

Thanks for sharing mate

[@Rogue_FPV]

Thanks for watching! 🙌🏻💪🏻🙌🏻

[@damianoair]

Dude I love this lol

[@Rogue_FPV]

Thanks Broski!!! Appreciate You 100%!!

[@lugwood4487]

Thanks uncle Roguey

[@Rogue_FPV]

My pleasure!

[@LarscoFPV]

Ooooo. I need this. 😅

[@Rogue_FPV]

I got you brother!!! 💪🏻🔥💪🏻🔥

[@flipfpv]

Great tip! Thanks

[@Rogue_FPV]

Thanks!! Glad you enjoy! 💪🏻💪🏻

[@flipfpv]

@@Rogue_FPV Hey just setting this up and wondering if you used the Betaflight Power & Battery tab >> Voltage Meter >> Multiplier Value to get the telemetry to read average cell voltage? That seems to work but just curious if there's a better way?

[@flipfpv]

Oh, I just found the flaw with that method - the auto PID profile selection by cell count won't work because Betaflight thinks you're using a 1S pack. Dang :(

[@Rogue_FPV]

@@flipfpv i just enter this in the cli set report_cell_voltage = ON save This sets the average cell voltage to be sent over telemetry in place of total lipo voltage

[@flipfpv]

@@Rogue_FPV Oh nice! I had no idea about that. I'll give that a try. Thanks!

[@cemuoimesogaf9009]

Вы очень умны и талантливы. Смогли до всего этого додуматься и более того, объяснить простыми словами другим. И наглядно показать.

[@luismanchego6856]

I wondered if you could do the same with crossfire and link quality to warn you when LQ is low? Great tip anyway 👍

[@Rogue_FPV]

Actually, you can do this quite easily. If you scroll to time 2:44, you see in my Special Functions that I have L02 and L03 set to Play Track / SigLow - SigCrt. Then if you scroll to time 4:57, you will see the 3 Logical Switched you need to create, for the alerts to work automatically, based on LQ.

[@luismanchego6856]

@@Rogue_FPV I see. I normally set up channel 12 for LQ on the nano Rx and AUX 8 in betaflight. Do I need to change this to set up the special functions and the logical switch? Thanks 👍

[@Rogue_FPV]

@@luismanchego6856 no, you don't have to make any changes to LQ channels, just set the 3 logical switches and the 1 special function exactly as shown, it will pickup RF Mode Change, and LQ from whatever channel the receiver sends it on. I use these settings on the radio models that I use all my various Crossfire and Tracer quads... some on 8 some on 12ch..

[@Seii-FPV]

@@Rogue_FPV - This is amazing. Just one question if I may... 4:57 sec mark, those 3 logical switches you've created for LQ alarms... do we need to set *AND switch* , *Duration* and *Delay* , or simply leave it unpopulated? Thank you so much in advance! EDIT: also, your L02 and L03 - *RQly* shows degrees, 80 and 70 respectively... but when I try that on my Tango II (FreedomTX), it gives me values in percentage. Why is that?

[@Rogue_FPV]

@@Seii-FPV @5:58 do not set an "AND" or "Duration" but do set a "Delay" of 5 seconds. The 5 second delay will prevent false alarms when you have battery sag from punch outs, etc... Also, my sensors are reading in degrees in this video because of an error. When I recorded the video I had changed receivers and I didn't do a "Discover New Sensors" on my radio. A value in percentages is correct like you have.

[@DinGuSco]

Are you still running Freedom TX on that Mambo or have you flashed it to Edge/Open?

[@Rogue_FPV]

Still freedom tx. 👍

[@Chechodronefpv]

Hey bro, on min 4:55 can you explain what does your L01 do, or what does RFMD means? I will appreciate, thanks.

[@Rogue_FPV]

My L01 is a logical switch that I created. The logical switch becomes active when RFMD (RF Mode) crossfire link state drops from 150hz to 50hz. This is for an Rssi alert that I have setup, and has nothing to do with the Audible Alerts for Battery voltage.

[@Chechodronefpv]

Thanks bro, I understand now.

[@IntensoX22]

Hello How do you tell RxBat to read cell voltage or overall voltage? Nice Video

[@Rogue_FPV]

If you want rxbat to report individual cell voltage instead of total lipo voltage, just enter the following command in the CLI and save. Set Report_Cell_Voltage = On

[@IntensoX22]

@@Rogue_FPV Thank you a lot!

[@Arek_R.]

On your main screen there is addition of SA and a timer, how do you add those positions there?

[@Rogue_FPV]

In the Model Setup Screen just below the Model Name, set Timer 1 to ON, and set the switch to activate the timer. You don't have to name the timer, but you want a Count Down timer, set a Start Time to count down from, and set the Value to Remain. Set Persistance to OFF, but Enable the Minute Checkbox, and set the Countdown to Voice. Next to Voice, set the value to 10 seconds, for a 10 second audible alert. You will need to set a special function to clear the timer with another switch though.

[@Arek_R.]

@@Rogue_FPV Thanks for detailed reply! I was hoping this screen area is completely customisable and I could display here rx battery voltage from the telemetry, seems like this is either blank or a timer...

[@Rogue_FPV]

you can add rx batt and other telemetry widgets in the secondary main screens. you can add them in the telemetry screen i think

[@Arek_R.]

@@Rogue_FPV I was able to make it that once I hold the left-right button on my t-pro, it shows customisable telemetry data and I was able to add it there

[@Rogue_FPV]

@@Arek_R. awesome!!! Glad that it worked out for you!! Happy to help always! 💪🏻💪🏻

[@emafpv]

I followed your tutorial for my other quad and it works. Now I made a new model on my radio for my new quad and once I connect all is keeps saying is 0 volts. I ran the CLI command in the comments and it still is doing the same thing. Any ideas

[@Rogue_FPV]

Make sure that telemetry is enabled in betaflight, and telemetry is being sent to your radio. I had telemetry issues with 4.4.2 on one of my quads, and went back to 4.4.0.

[@emafpv]

@@Rogue_FPV thanks for the fast reply. I’m on 4.4.2 with my original and it works. And your talking about the telemetry switch in the receiver tab or settings in edge TX?

[@Rogue_FPV]

@@emafpv the receiver tab

[@leomatis_]

how do you set your rxbt to report avg voltage instead of total?

[@Rogue_FPV]

If you use betaflight, enter this command in the cli. set report_cell_voltage = ON save

[@leomatis_]

@@Rogue_FPV thanks mate!!

[@Chechodronefpv]

Bro can you tell me how can I get RXBt value for only a cell, mine says the total value of the 6 cells, and I would like just the average cell battery. Thanks.

[@Rogue_FPV]

You have to type “report_cell_voltage=on” in the cli and save

[@TavoFourSeven]

just got the fatfish f16 and it only says battery, not RxBt. I had it working on my pocket and this is the only difference. kinda neccessary with my own camera on that hummingbird v3 board.

[@Rogue_FPV]

“Battery” is the radio battery level, not the quad. You can do a “discover sensors” in the Telemetry screen on your radio with the quad plugged in. Make sure that Telemetry is enabled in the Receiver Tab of betaflight too.

[@TavoFourSeven]

@@Rogue_FPV seems to have done it, thank you 2X bro

[@Rogue_FPV]

@@TavoFourSeven happy to help out!! 💪🏻💪🏻

[@certifyFPV]

Hi, how do you get that stick overlay on your screen? I CANT find mine!

[@Rogue_FPV]

Just scroll through the Main pages/screens on your radio with the Page Button when you turn the radio on until you see it. There are 5 Main Screen pages, the radio will always default back to the screen that was displayed when the radio was powered off.

[@certifyFPV]

@@Rogue_FPV is that in system settings?

[@Rogue_FPV]

@@certifyFPV no, just from the main screen. What radio are you using?

[@certifyFPV]

@@Rogue_FPV i’m using the jumper t lite v2 i’ve seen people have different screens but im unable to actually find out how to change it

[@Rogue_FPV]

@@certifyFPV the page buttons are the switches labeled “Up and Down” to the right of the screen. Just push Up until you see the screen with the stick overlay.

[@Deathwish_fpv]

Will this work trying to set it up for the battery on the radio itself..or just the drones

[@Rogue_FPV]

You can do this the same way but for radio battery, select “batt” instead of “rxbt” and set your low voltage threshold accordingly.

[@Deathwish_fpv]

@@Rogue_FPV oh ok..thanks

[@Deathwish_fpv]

On my tx16s radio edgetx 2.8..I dont see the RxBt option ..it just has batt option

[@Kusokzemli]

День добрый Привет из Узбукистана

[@Rogue_FPV]

привет друг! 👋Пришлось пользоваться переводчиком, прошу прощения за непонимание.

[@GenCodeFPV]

How did you get the rxbt to report average cell voltage?

[@Rogue_FPV]

In the cli you can type Set report_cell_voltage=on Then Save

[@GenCodeFPV]

@@Rogue_FPV ok, sorry I use KISS not BF :( Wondering if there was a script to take the value and divide by 4 in openTX

[@Rogue_FPV]

@@GenCodeFPV I dunno about a script I’m sure it can be done. I use kiss ultra and I have cell voltage in the osd, but in the radio I just set the alerts for total lipo min voltage of 21v.

[@GenCodeFPV]

​@@Rogue_FPV I tried creating this with ChatGPT ;) it works fine as long as this line is commented out -- setCustomSensorValue("CelS", -1) it looks like it won't let me set a custom sensor, but once commented out it will display the cell voltage (assuming its 4s) but to use it in a logical switch I need to get its value somewhere. -- Define the function to set a new sensor value local function setCustomSensorValue(sensorName, value) system.setTelemetryValue(sensorName, value) end -- Main function local function run(event) local sensorName = "RxBt" -- Set the battery telemetry ID local cellNumber = 1 -- Set the desired cell number -- Retrieve the voltage value from the battery telemetry local voltage = getValue(sensorName) -- Check if the voltage value is valid if voltage then -- Divide the voltage by 4 local cellVoltage = voltage / 4 -- Display the cell voltage on the transmitter's screen lcd.clear() lcd.drawText(1, 1, "CellVoltage: " .. string.format("%.2f V", cellVoltage), MIDSIZE) -- Set the cell voltage as a new custom sensor value setCustomSensorValue("CelS", cellVoltage) else -- Display an error message if voltage retrieval failed lcd.clear() lcd.drawText(1, 1, "Error retrieving", MIDSIZE) lcd.drawText(1, 25, "cell voltage", MIDSIZE) -- Set an error value to the custom sensor setCustomSensorValue("CelS", -1) end -- Return 0 to prevent the script from interfering with other functions return 0 end -- Register the run function to be called on each telemetry update return { run=run }

[@nvembrace]

I have edgeTX and there is no option for RxBt but there is a choice for Batt. Any suggestions I would appreciate it.

[@Rogue_FPV]

Batt is the radio battery, you just need to plug in the drone and click “discover new sensors” on the telemetry screen on the radio. RXbatt should populate. You need the drone on to do this, it has to be sending telemetry back to the radio.

[@nvembrace]

@@Rogue_FPV I did that and now I have RXbt but no sound when it goes below the voltage I set which is 3.3. I do know the sound file is working, I have sound on all my switches. I watched your video many times and mine is set up just like yours. I will try it on another happymodel board and see. I will let you know what happens. I won't worry you if it doesn't work but I have learned things I didn't know so I'm happy. Thanks for your help

[@Rogue_FPV]

@@nvembrace make sure that you’ve done every step one more time. Make sure that if you use the per cell voltage you tell the fc to report per cell voltage. If you haven’t done that, the radio will want to call out the alert when the whole pack drains to 3.3v not 3.3v per cell

[@nvembrace]

@@Rogue_FPV Okay that must be my problem because I didn't tell the FC to do anything. Would that be a command that has to be done in betaflight CLI and if so can you give me the command? Thanks

[@Rogue_FPV]

@@nvembrace enter these 2 lines in the betaflight CLI and hit enter - set report_cell_voltage = ON save

[@emmsfpv8244]

hi, how to set up average cell voltage? mine is set to total voltage > thanks folks

[@Rogue_FPV]

Enter these 2 lines below in the betaflight CLI Tab with your quad plugged in, hit enter key after each line. set report_cell_voltage = ON save

[@Deathwish_fpv]

Set mine up with out a switch..play automatically...shall see if it works

[@Rogue_FPV]

Nice! That’s how I have mine setup! 💪🏻💪🏻

[@harshlalwani4311]

I have no "rxbatt" on my mambo v1.34. I want to try v1.35 but it's in beta. Should I?

[@Rogue_FPV]

I use the latest, but that shouldn’t matter for Rxbat. Have you done a “search for new sensors” when a receiver is connected?

[@harshlalwani4311]

@@Rogue_FPV thanks for replying. How can I do that?

[@Rogue_FPV]

@@harshlalwani4311 on your radio. Scroll to the Model Telemetry page. Scroll down until you see the line “search for new sensors” then click on it and wait 10 seconds. Make sure to have the quad plugged in and bound to the radio, you will not gain the rxbt if the quad isn’t talking to the radio.

[@harshlalwani4311]

@@Rogue_FPV Thanks a lot man! I wouldn't have guessed it... I will give It a try..

[@thefreezezone4583]

i have no RxBt option in logical screen drone powered on or off...sup with these videos? Ive been trying to set a drone voltage on my radio all day, not one video is correct, yet all are Edge TX.....thats going on here?

[@Rogue_FPV]

with the quad plugged in and bound to your radio, on the radio go to your model telemetry page, and do a "search for new sensors". if you have telemetry enabled on your RX and in betaflight you should see RxBt pop up in the list of sensors. Then you can ad it as a logical switch. Sounds like your telemetry is disabled in betaflight receiver tab...

[@thefreezezone4583]

@@Rogue_FPV HAHA yeah, I was hit by a double whammy, didnt have batt power and telemetry was off in beta, ty for your time and knowledge

[@gregorydahl]

Iwhat is " set rxbt " mean .

[@Rogue_FPV]

That’s setting the alert for the level of the quad battery. Rxbt = battery voltage seen from the receiver.

[@gregorydahl]

@@Rogue_FPV So the model needs to be on and connected for my tx to detect the rxbatt ?

[@Rogue_FPV]

@@gregorydahl yes, the model needs to be turned on to send the telemetry to the TX from the RX

[@gregorydahl]

@@Rogue_FPV i have a mobula 7 spi rx . It does not have telemetry maybe . I see no rxbatt choice .

[@Rogue_FPV]

@@gregorydahl depending on the protocol being sent over spi - ELRS / FRSKY / ETC... the rxbatt / rxbt may be sent over telemetry or it may not be. Also, check in the receiver tab or the config tab in betafight depending on version, and ensure that telemetry is enabled there.