Bandwidth switching
This is an experimental functionality that allows you to switch the WiFi channel width being used for the transmission from the Air unit to the Ground. The available bandwidths are:
5 MHz, 10 MHz and 20 MHz
Using a narrower bandwidth will allow for greater range, using a wider bandwidth will allow for higher quality video but at the cost of reduced range.
This experimental feature only works with Atheros based cards.
To enable this functionality make the following changes to the settings file
openhd-settings-1.txt in the boot partition.SecondaryCamera=No
RC=mavlink
PrimaryCardMAC=00126d726127
This will enable the bandwidth switching feature. Be aware that the MAC address of the most powerful WiFi card on the Ground unit needs to be specified. For example if you have one TP-Link and one Wifistation, use the mac address of the Wifistation card as this is significantly more powerful.
And optionally change the RC channel used to switch between the bandwidths:
ChannelToListen2=8
You can also adjust the PWM values if they are out of range for your TX:
Band5Below=1200
Band10ValueMin=1200
Band10ValueMax=1650
Band20After=1650
Also, it is recommended to change this in
joyconfig.txt:#define AXIS7_INITIAL 1000
To
#define AXIS7_INITIAL 1800
That will prevent bandwidth from changing at boot time.