Update README.md

README.md

@@ -19,7 +19,7 @@ The 'Long Vario' release 2 features a new technology 320x240 pixel IPS LCS displ
 The third generation 'XC Vario' uses the same display as the long vario, but came with a new sensor board 61x64 mm, vertically mounted behind the display board. The sensor board has a RJ45 connector for electrical connections, digital potentiomenter, and some more features like software update over the air, serial output and serial to bluetooth bridge and connector for external audio. It still has an audio amplifier with 1.2 Watt and an efficient loudspeaker on board, and has a just 34 mm long CNC fabricated aluminium housing and can be from back of the I-Panel as any other standard 57 mm instrument. A three digit number of boards have been fabricated and has been offered via .de webshop, selling the hardware for an interresting price.
 
 4. master branch (default, what you see here)
-The fourth generation XCVario-21 or XCVario series 2021 has identical feature set as the series 2020, but has been pimped up with some nice hardware gimicks. The device got a second serial interface (S2) following the IGC standard pinout to be open for more applications with external serial devices. The interface pins RX/TX are programmable to be able to twist RX/TX lines by setup to minimize need for custom cables, so mostly a standard 1:1 patch  cable can be used. The second interface S2 can also power external devices and the same connector features one addittional programmable analog or digital input, e.g. for flarm sensor application. The digital audio amplifier has an increased power of 2 Watt's providing less THD at high volumes. Furthermore a 6 axis 'Attitude and Heading Reference System' (AHRS) has been placed on the board to provide acceleration to the flight computing software plus pitch and angle of bank for a connected XCSoar application. As extenal hardware a flap sensor has been developed, indication your current flap position on the display, plus a high precision magnetic sensor board featuring the new QMC5883L chip can both be connected to S2 interface. The shop opened January 2021 with a three digit number of new 2021 hardware devices http://xcvario.com/store webshop. Mid 2021 the board was extended by a CAN interface and named XCVario-22. 
+The fourth generation XCVario or XCVario series 21,22,23 has identical feature set as the series 2020, but has been pimped up with some nice hardware gimicks. The device's got a second serial interface (S2) following the IGC standard pinout to be open for more applications with external serial devices. The interface pins RX/TX are programmable to be able to swap RX/TX lines by setup to minimize need for custom cables, so mostly a standard 1:1 patch  cable can be used. The second interface S2 can also power external IGC compatible devices and the same connector features one addittional programmable analog or digital input, e.g. for flarm sensor application.  Furthermore a 6 axis 'Attitude and Heading Reference System' (AHRS) has been placed on the board to provide acceleration to the flight computing software plus pitch and angle of bank for a connected XCSoar application. As extenal hardware a flap sensor has been developed, indication your current flap position on the display, plus a high precision magnetic sensor board featuring the new QMC5883L chip can both be connected to S2 interface. The shop opened January 2021 with a three digit number of new 2021 hardware devices http://xcvario.com/store webshop. Series 22 devices were extended by a CAN interface. The digital audio amplifier has an increased power of 3 Watt's in series 23 providing less THD at high volumes, an antiglare and anti-fingerprint display was added, and the IMU got a temperature control for lower temperature related drift. 
 
 [List of Software Releases](https://github.com/iltis42/XCVario/releases/) , latest release on the top <br>
 
@@ -49,6 +49,7 @@ The design supports the follwing sensors:
 * Outside Temperature
 * Battery Voltage
 * Acceleration and Rotation
+* Optional Earth magnetic field
 
 The ESP32 module contains a bluetooth and WLAN sender module plus serial interfaces, so we are able to transmit wireless or wired all data to any navigation device running XCSoar, LK8000 and more in various formats as there is the native XCVario, Borgelt, Cambridge and Openvario format,so devices can operate as full glide computer with TE-Vario, Barometric Altitude, Speed and more.