- Joined
- Dec 18, 2019
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- 6,477
Not a PLC, but an up rated small, Arduino like, processors can be found at https://www.pjrc.com/store/teensy41.html They also have a great forum there, and really try to help out their customers. I bought my Teensy 4.1's there. A Teensy is an Arduino with some horsepower, and as the name suggests, it is small. They have developed a lot of libraries that work very well on their platforms. For a little less money, and a little less I/O, you can get a Teensy 4.0 for about ~$23. The owner is into audio, and PJRC offers a decent audio board and free audio design software for making your own audio applications.
A Teensy4.0 will beat the pants off of most Arduino processors for computation - but doesn't have built-in wifi, nor is it 5V tolerant. In english, that means if you hook up the I/O to +5V, even for an instant, (few nanoseconds!) you destroy the part. It uses 3.3V for it's I/O. Nonetheless, the Teensy4.X are quite attractive from an instructions per second per $ perspective. The 4.X processors do single precision floating point just as fast as fixed point or integer math. Double precision takes 2 cycles, instead of 1 for single. This may be important if your application requires a lot of floating point math, or you simply have to have your lathe spinning at 5000 RPM and not lose counts on your encoder.
FYI, that RPM limit is about what I calculated on my ELS. The limit was not the Teensy, it was the physical quadrature encoder electrical bandwidth, even if it spun faster, the output signal wouldn't change faster. My lathe can't spin at 5000 RPM, the chuck would explode. I have about a 2.5:1 safety factor on the RPM. In practice, I rarely use speeds near the chuck rating, so my safety factor is probably 5:1 or better. More than enough for hobby use.
A Teensy4.0 will beat the pants off of most Arduino processors for computation - but doesn't have built-in wifi, nor is it 5V tolerant. In english, that means if you hook up the I/O to +5V, even for an instant, (few nanoseconds!) you destroy the part. It uses 3.3V for it's I/O. Nonetheless, the Teensy4.X are quite attractive from an instructions per second per $ perspective. The 4.X processors do single precision floating point just as fast as fixed point or integer math. Double precision takes 2 cycles, instead of 1 for single. This may be important if your application requires a lot of floating point math, or you simply have to have your lathe spinning at 5000 RPM and not lose counts on your encoder.
FYI, that RPM limit is about what I calculated on my ELS. The limit was not the Teensy, it was the physical quadrature encoder electrical bandwidth, even if it spun faster, the output signal wouldn't change faster. My lathe can't spin at 5000 RPM, the chuck would explode. I have about a 2.5:1 safety factor on the RPM. In practice, I rarely use speeds near the chuck rating, so my safety factor is probably 5:1 or better. More than enough for hobby use.