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| Pi PICO DRO/Quill-Knee combiner |
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| BillTodd:
I'm just throwing this out here in case anyone is interested. I'm knocking-up a DRO and Knee-Quill scale combiner using a Pi PICO. Both use the PICO's PIO (programmable input/output) to count the quadrature input from the scales . The four PIOs unload the fast counting operations from the main program, so enabling the rest of the code to be written in MicroPython . The Quill-Knee combiner reads each scale (they can be different resolutions and could even be a capacitive caliper type scale with appropriate driver) then add or subtracts the result before pulsing a quadrature output to drive the Z input of a DRO (this can also be a different resolution) . As a DRO, the four inputs can count any resolution , I'm setting this at 0.1um (100nm), at upto about 12MHz (it would take some cranking to get the knee upto that speed ;-0) ATM I'm considering a separate SDD1322 128x64 by 16 greyscale display for each Axis (or may each pair) as a single large display may eat too much the PICO available RAM. I want to implement my scrolling analogue fractional display that I used on a Visual Basic based DRO i made some years ago : https://drive.google.com/file/d/1rM2Hi0BpiGD3UBXQO2KIPjKZfed-vfZa/view?usp=drive_link If anyone is interested, please respond and I'll post the progress here. |
| JHovel:
Very interested Bill! As you know, I built your DRO of 15 years or more ago back then. I've still got it! |
| JamesC:
A very long time lurker, I too would be very interested in following this and maybe if my skills alow building one. James |
| BillTodd:
Hi Joe , James good to have you onboard :) This doesn't look much ATM but this is the heart of the DRO : On the extreme left is a hand-wheel encoder and right , a servo motor they are standing in for a glass scales giving a 2000 and 5000 pulse per rev quadrature output . Each feeds a PICO PIO programmed as a quadrature counter and displayed as K: ans Q: . A third PIO input , Z: , is fed from the quadrature output pins @ 2000pulse per unit which is currently squirting out the sum of K and Q (the slight error in the counts is due to the difference in resolutions (my mill would not see those last two digits) |
| Fred Bloggs:
Hi. Im just in the process of converting my 1950's German vertical mill to 3 phase with a VFD and your DRO would be a good addition, please post :nrocks: Best regards Fred |
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