Dual Sonar setup for left and right turns - MB1240

The old pixhawk had a 5 pin ADC port with two separate pins for reading the output signal from the sonar. The new pixhawk 2 only has a 3 pin ADC port with one pin for sonar signal. Does anyone know how I could get two sonars working off the ADC port? I am using MB1240 Maxbotics sensors.