The dual mode active bridge has two switchable display modes. The display is a TWI linked 20character 4 line display, with two combined programmes. A switch is connected to line pin 13 of the arduino uno, while in tied low, the bar graph display is chosen, illustrating the received signal on the top bar graph, and on the bottom graph the transmitter power output. The transmitter calibration at full analogue input of 5volts, equates to 10watts of Tx power. As the bitx 40 has a power output max at 12volts of 7watts, the 10watt range is suitable. The rx signal strength goes up to S9 on the bar graph display, which equates to about 50dB dynamic range from the receivers agc, should an agc citrcuit be applied. I found one audio derived agc circuit on the web, so this would be appropriate for the bitx receiver section. The 12 volt supply to the audio derived agc circuit will need to use a resistor divider network arrangement to scale the 12volt down to max 5 volts, so not to over load the analogue port input. It may be an idea to use a 4.7 volt zener diode as a safety circuit on the input of the arduino uno analogue port.
The Arduino uno code for the "dual mode active bridge" can be found on the download page of the ham radio tech website, www.radiohamtech.com