Vario
The FlyPlus firmware can provide an accoustic feedback of the rising or sinking plane, similar to the dedicated variometers, provided that there is an altitude or pressure sensor on-board of the aircraft.
An I-Bus altitude sensor, such as Turnigy TGY-CAT01, or a home-made
one (such as
this one by @Yenya).
Connect the sensor to the receiver, and verify you can see it in
the System ⭢ Sensors List menu.
The firmware monitors a selected sensor, and provides accoustic feedback based of the sensor value change. There are two variants of the sound:
-
sensor value increasing (plane rising): a short beep at 1200 Hz providing the baseline, then a short pause, and then a longer beep representing the sensor value increase (up to 2400 Hz).
-
sensor value decreasing (plane sinking): a short beep at 1200 Hz providing the baseline, no pause in between, and then a longer beep representing the sensor value decrease (down to 600 Hz).
Go to the System ⭢ Extra ⭢ Vario menu, which looks like this:
The first line in the menu screen selects the Sensor to be used as vario. It could be a pressure sensor, altitude sensor, or even something completely different that you want to hear changing, such as SNR.
The second line selects Gain: the value controls how much the sensor value difference affects the sound frequency. The higher gain means higher frequency difference for the same sensor value difference. The Gain value in this menu can be set from 1 to 15:
The Gain of 3 represents the baseline - sensor difference of +1 means the sound frequency difference of 1 Hz when the value increases, and 0.5 Hz when it decreases (we have 1200 Hz range on the plus side, but only 600 Hz on the minus side - it is a poor man's way to approximate the logarithmic nature of the sound frequency :-)
Each step in the Gain value means twice as big (or half as big) frequency response. For example, with Gain set to 1 the sensor value difference of +8 yields the frequency of 1202 Hz and the sensor value difference of -4 yields the frequency of 1199 Hz; with Gain of 6 the sensor value difference of +1 yields the frequency of 1208 Hz and the sensor value difference of -1 yields the frequency of 1196 Hz, and so on.
The raw sensor values are used. So for example, the altitude sensor's raw value is in centimeters. When the Gain is set to 4 (which is what @Yenya uses), an altitude difference of +1 m means the second beep at 1400 Hz, and an altitude difference of -1 m means the second beep at 900 Hz.
The Deadband value denotes the difference range in which Tx does not beep at all. With the altitude or pressure sensor it represents a level flight. For example, a deadband of 100 used with altitude sensor (which has its raw measurements in centimeters, as we noted above) means that the difference in altitude since the last beep smaller than 1 meter (100 centimeters) means silence.