开云体育

Suppose I measure with a millivoltmeter the voltage across D2. Is it correct then to set the vbat_offset parameter to the value just read ?

TNX
Alberto

I don't know what the firmware does to calculate the battery level but I suspect that setting vbat_offset to 150 (as suggested by Hugen) is because the difference in voltage drop between the Schottky diode used prior to v1.34 and the 1n4148 used now is 150 mVolts.

Just a guess...

Roger

Apparently what I supposed seems to be correct... copied from the PDF listing the console commands of the nanoVNA :

===================
vbat_offset – allows the battery voltage shown on the GUI config screen to be ‘calibrated’ by specifying a
millivolt offset value (typically the Vf of the diode at D2).
Useage: vbat_offset [mV] Returns currently saved value if [mV] is blank.
Use saveconfig command to save offset value.
==================

Alberto

Hi Alberto,

I set it up by measuring the voltage at the battery connection points, and noted this.
I checked the voltage displayed with nanoVNA-Saver or nanoVNAPartner. I typed the difference between the two with Terra Term at vbat_offset.
That is all.

73, Gyula

Hi Alberto,

I set it up by measuring the voltage at the battery connection points, and noted this.
I checked the voltage displayed with nanoVNA-Saver or nanoVNAPartner. I typed the difference between the two with Terra Term at vbat_offset.
That is all.

=====================

Hi Gyula,

? thanks. Have you perhaps checked if the offset so measured corresponds to the voltage drop across D2 ?
That would seem logical...

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/*73 Alberto I2PHD*
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