Hello all,
I was wondering if anyone is using a Pokeys57cnc board and could answer some questions. I am retrofitting an new to me milling machine and am trying to create a front panel control board. I would like to incorporate spindle speed and feed speed over ride. I was hoping to use the analog inputs on the Pokeys board with a potentiometer for each.
My first question is is it possible? Can this be done in Mach3 and can anyone help with the filter math? Below is the only information I can find in the manual.
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 𝑦(𝑘=𝑦(𝑘−1)∗𝑓𝑖𝑙𝑡𝑒𝑟𝑓𝑖𝑙𝑡𝑒𝑟+1+𝑢(𝑘∗1𝑓𝑖𝑙𝑡𝑒𝑟+1
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: 𝑓𝑐=10 𝑘𝐻𝑧2𝜋∗𝑓𝑖𝑙𝑡𝑒𝑟
Sample u(k) is produced according to the following equation 𝑢(𝑘=𝑈(𝑘[𝑉]3.3 𝑉∗4095
where U(k) (in Volts) is a voltage present on the selected analog input pin.
Algebra was over 35 years ago and I don't remember much.
The over ride buttons in Mach3 are a format string and I am wondering if they would need to be modified? Or am I approaching this wrong and should be using PWM with a percentage?
Thank you for looking and any direction you can offer,
Jeff