Here are the measured resistance values for each button press on the remote control.
The remote control for the Alesis ADAT HD24 recorder uses combinations of 1/8 watt ±5% resistors to alter an input voltage.
I don’t have access to the recorder unit. Based on what I see inside the remote control I’m assuming it determines which button is pressed by measuring the voltage that is returned. Each button would lower the voltage by a different amount, thus making the measured value for each button press unique and identifiable.
The supply voltage that the recorder sends to the remote is unknown to me, but is likely one of the modern standard rail voltages — 3.3V, 5V, or 12V.
To obtain the following values I connected a digital multimeter across the tip and sleeve of the 1/4″ cable attached to the remote. All measurements are in Ohms.
Interestingly, the switch labels on the PCB differ slightly from the button labels on the case.
Also, I know this technically isn’t a pin out.
|Measured Value (Î©)
|(value read with no buttons pressed)