User Manual
PoKeys user manual
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Figure 16: Matrix keyboard configuration for a 4x3 matrix keyboard
7.6. Analog inputs
Analog input function is only available on pins 41 to 45. These analog inputs can also be freely
mapped to any of the 6 joystick axis; X, Y, Z, rotation X, rotation Y and throttle.
Analog inputs have a resolution of 12 bits and are sampled at a fixed rate of 10 kHz, then fed through
adjustable digital low-pass filter with the following equation
where y(k) is the output analog value, u(k) is a new A/D sample and filter is a user-adjustable
constant. For proper operation of the digital filter, an analog low-pass filter with a cut-off frequency
of 5 kHz must be used on each analog input. The following equation gives the relation between value
of filter and filter’s cut-off frequency:
Sample u(k) is produced according to the following equation
where U(k) (in Volts) is a voltage present on the selected analog input pin.
PoKeys configuration software usage
To open analog inputs dialog, go to Peripherals menu and select ‘Analog inputs and outputs’. Dialog
below appears. To enable display of analog input channel, check the appropriate check box. It is
enabled only when the input is set up as analog input.
The progress bar displays the current voltage at the pin with the maximum at 3.3V. Below the input
selection boxes user can set low-pass filtering for analog inputs. When analog input signal appears to