It is a easy however extraordinarily helpful trick: press a button and your radio tells you the quad’s battery voltage. You’ll be able to simply set this up on any EdgeTX radio, and it’s particularly helpful for pilots who wouldn’t have OSD. I can even present a sophisticated setup the place your radio routinely alerts you when the drone’s battery voltage will get low. That is best in case you turn out to be too centered on flying to continuously verify your voltage.
Conditions
- Your radio is working EdgeTX
- Your quad helps telemetry (radio hyperlinks comparable to ExpressLRS and Crossfire work)
Additional Studying:
Why Use Battery Voltage Voice Callouts?
You need to keep away from over-discharging your LiPo battery, so having the ability to verify battery voltage at any time is crucial.
If you’re too busy monitoring the OSD throughout flight—or in case your quad doesn’t have OSD in any respect (for instance, when flying line of sight with out goggles or a display screen)—audible voltage callouts are extraordinarily useful.
Additional studying: Perceive the significance of monitoring battery voltage and alternative ways to verify it: https://oscarliang.com/monitor-measure-battery-voltage-alarm-drone/
Voltage Callout Utilizing a Change
With the press of a swap—ideally a momentary swap, although any swap will work—your radio tells you the drone’s voltage.
Step 1: Make Certain Telemetry Is Working
Earlier than setting something up, affirm that telemetry is working in your quad. When telemetry is working, the quad shall be continuously sending information to your radio, together with battery voltage.
In Betaflight Configurator
- Go to Receiver tab
- Guarantee Telemetry is enabled
- Save and reboot
On the Radio
- Energy in your quad (props off)
- In your radio:
- Open Mannequin Settings (press the MDL button as soon as)
- Navigate to the Telemetry web page (press PAGE)
- Scroll right down to Sensors and choose “Uncover new”
- Inside just a few seconds, an inventory of telemetry sensors ought to populate.
What you might be on the lookout for is:
- RxBt (receiver battery voltage)
When a battery is plugged into the drone, this worth ought to replace in actual time (how typically it updates is dependent upon your telemetry ratio setting in ExpressLRS LUA script).
Step 2: Confirm Battery Voltage Accuracy
Verify that the RxBt voltage studying is correct utilizing a multimeter or a battery voltage checker (get your voltage checker right here)
If the worth is wrong, you could have to calibrate it in Betaflight beneath the Energy & Battery tab. That is uncommon—most flight controllers work accurately out of the field.
Step 3: Assign a Momentary Change to Communicate Voltage
Go to Particular Features
- Open Mannequin Settings (press MDL button as soon as)
- Navigate to Particular Features (press PAGE button to get there)
- Choose an empty line and click on Enter button
Configure the Perform
Set the next:
- Change: Select a unused swap (ideally a momentary button, e.g. SH↓ within the GX12)
- Perform: Play Worth
- Parameter: RxBt (You might also see RxBt+ and RxBt-, these are the utmost and minimal worth recorded throughout flight. For those who simply need to verify the present battery voltage, use RxBt.)
- !-: this selection ensures the worth is performed solely as soon as whereas the swap is energetic
- Allow: ✔ Checked
That’s it.
Check it
- Press the assigned swap
- Your radio ought to say one thing like: “twenty two level 9 volts”.
You now have on-demand battery voltage callout.
Bonus: Reporting Common Cell Voltage
By default, RxBt stories the entire LiPo voltage. You’ll be able to optionally configure it to report common cell voltage, which many pilots discover extra intuitive—particularly when flying quads with totally different cell counts, you don’t have to do the calculations in your head.
Within the Betaflight CLI, enter:
set report_cell_voltage = onsave
Superior Setup: Low Voltage Warning
If you wish to be further secure—particularly in case you get immersed in flying and overlook to verify voltage—you’ll be able to arrange an automated low-voltage warning.
On this instance, the radio will warn you when voltage drops beneath 3.5V per cell. You’ll be able to regulate this threshold as wanted.
Step 1: Setup Logical Change
- Navigate to Logical Switches in your radio
- Scroll to an empty line (for instance, L01) and press ENTER
- Configure the logical swap as follows:
- Perform: a<x
- V1: RxBt
- V2: 3.5V (you’ll be able to change it to any voltage you need)
- Delay: 3 seconds (this delay reduces false positives brought on by voltage sag throughout punchouts)
Necessary: Be sure that the next CLI command is enabled so RxBt stories voltage per cell set report_cell_voltage = on
Step 2: Create a Particular Perform
- Go to Particular Features
- Add a brand new line
- Choose the logical swap created within the final step (in our instance it’s L01)
Set Perform to Play Observe or Play Worth:
- Select “Play Worth”, and choose RxBt to name out the precise voltage.
- Set Repeat Delay: In order for you the alert to repeat, set a repeat delay (e.g., 10 seconds). For those who solely need it to alert as soon as, set it to !.
- ✔ Allow it.
Your radio will now routinely provide you with a warning when the battery voltage falls beneath your set threshold. And it’ll repeat the warning each 10 seconds so long as the voltage is beneath that restrict.
Or, you’ll be able to select “Play Observe” as an alternative, and choose “lowbat” to play the “low battery” warning. You’ll be able to even report one thing distinctive into an audio file and play it.
Conclusion
Establishing audible battery voltage callouts and low-voltage warnings in your EdgeTX radio considerably improves each security and situational consciousness. It permits you to deal with flying as an alternative of regularly monitoring battery ranges.
Whether or not you like handbook voltage checks utilizing a swap or automated alerts based mostly on voltage thresholds, these setups make sure you by no means miss a low-battery warning once more.