Battery Voltage Callouts / Low Voltage Voice Alerts on Any EdgeTX Radio – Setup Information

It is a easy however extraordinarily helpful trick: press a button and your radio tells you the quad’s battery voltage. You possibly can simply set this up on any EdgeTX radio, and it’s particularly helpful for pilots who wouldn’t have OSD. I may also present a complicated setup the place your radio routinely alerts you when the drone’s battery voltage will get low. That is superb if you happen to turn into too centered on flying to consistently test your voltage.

A few of the hyperlinks on this web page are affiliate hyperlinks. I obtain a fee (at no further value to you) if you happen to make a purchase order after clicking on one in every of these affiliate hyperlinks. This helps help the free content material for the group on this web site. Please learn our Affiliate Hyperlink Coverage for extra data.

Stipulations

• Your radio is working EdgeTX
• Your quad helps telemetry (radio hyperlinks reminiscent of 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 test 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)—audible voltage callouts are extraordinarily useful.

Additional studying: Perceive the significance of monitoring battery voltage and other ways to test it: https://oscarliang.com/monitor-measure-battery-voltage-alarm-drone/

Voltage Callout Utilizing a Change

With the press of a change—ideally a momentary change, although any change 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 will probably be consistently sending knowledge to your radio, together with battery voltage.

In Betaflight Configurator

1. Go to Receiver tab
2. Guarantee Telemetry is enabled
3. Save and reboot

On the Radio

1. Energy in your quad (props off)
2. In your radio:
   1. Open Mannequin Settings (press the MDL button as soon as)
   2. Navigate to the Telemetry web page (press PAGE)
3. Scroll all the way down to Sensors and choose “Uncover new”
4. Inside a couple of seconds, a listing of telemetry sensors ought to populate.

What you might be searching 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

Affirm 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 inaccurate, chances are you’ll must 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 Converse Voltage

Go to Particular Capabilities

1. Open Mannequin Settings (press MDL button as soon as)
2. Navigate to Particular Capabilities (press PAGE button to get there)
3. Choose an empty line and click on Enter button

Configure the Operate

Set the next:

• Change: Select a unused change (ideally a momentary button, e.g. SH↓ within the GX12)
• Operate: Play Worth
• Parameter: RxBt (You might also see RxBt+ and RxBt-, these are the utmost and minimal worth recorded throughout flight. In case you simply need to test the present battery voltage, use RxBt.)
• !-: this selection ensures the worth is performed solely as soon as whereas the change is energetic
• Allow: ✔ Checked

That’s it.

Take a look at it

• Press the assigned change
• 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 reviews the full LiPo voltage. You possibly can 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 must do the calculations in your head.

Within the Betaflight CLI, enter:

set report_cell_voltage = on
save

Superior Setup: Low Voltage Warning

If you wish to be further secure—particularly if you happen to get immersed in flying and neglect to test voltage—you possibly can arrange an computerized low-voltage warning.

On this instance, the radio will warn you when voltage drops under 3.5V per cell. You possibly can alter this threshold as wanted.

Step 1: Setup Logical Change

1. Navigate to Logical Switches in your radio
2. Scroll to an empty line (for instance, L01) and press ENTER
3. Configure the logical change as follows:
   1. Operate: a
   2. V1: RxBt
   3. V2: 3.5V (you possibly can change it to any voltage you need)
   4. 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 reviews voltage per cell set report_cell_voltage = on

Step 2: Create a Particular Operate

1. Go to Particular Capabilities
2. Add a brand new line
3. Choose the logical change created within the final step (in our instance it’s L01)

Set Operate to Play Observe or Play Worth:

• Select “Play Worth”, and choose RxBt to name out the precise voltage.
• Set Repeat Delay: If you would like the alert to repeat, set a repeat delay (e.g., 10 seconds). In case you solely need it to alert as soon as, set it to !.
• ✔ Allow it.

Your radio will now routinely warn you when the battery voltage falls under your set threshold. And it’ll repeat the warning each 10 seconds so long as the voltage is under that restrict.

Or, you possibly can select “Play Observe” as a substitute, and choose “lowbat” to play the “low battery” warning. You possibly can even document one thing distinctive into an audio file and play it.

Conclusion

Organising audible battery voltage callouts and low-voltage warnings in your EdgeTX radio considerably improves each security and situational consciousness. It permits you to concentrate on flying as a substitute of regularly monitoring battery ranges.

Whether or not you favor handbook voltage checks utilizing a change or computerized alerts based mostly on voltage thresholds, these setups make sure you by no means miss a low-battery warning once more.