Hello,
I am retrofitting a D&M CNC mill. I have installed an auto draw bar and a rotary tool changer. I have gone through a lot of electronics and have changed directions several times. I am a bit frustrated and am hoping someone might be able to guide me in the right direction. I abandoned all the "cheap Chinese stuff" as advised by many and am now worse off than before! I am now tying to make a go with the Pokeys57cnc sold as Mach3 compatible with included plugin. The after sale sales pitch is to abandon my 7 years of experience with Mach3 and buy Mach4! Learn new software and re-script everything of done In Mach3? Sounds like more fun then a barrel of monkeys!
The Poykeys57cnc states in its manual that pin 17 is assigned to the spindle speed sensor. It specs the pin to be a 3.3 v logic that accepts .8 v low and 2.2 v high. It can take a maximum of 5v as that is the supply voltage they provide for the sensor you use. I am using a CYN70 reflective sensor and have wired it to supply .5 v low and 4.85 high.
Here is the issue I attach the signal to pin 17 on the Pokeys board and it becomes 1.25v low? I e-mailed back and forth with support and was told there is a weak pull up resistor on all of their pins. I have tried using an op amp as a voltage controlled schmitt trigger and the low is worse. I have tried every resistor combination along with a voltage divider to bring the signal low enough to overcome Pokeys pull up resistor. They started to try and help through support and today e-mailed me that they do not offer electrical engineering services for free and that the problem was outside the scope of their support.
I asked for a solution to a problem they created. Tell me what sensor to use or what to do to get the signal low enough for their design? If you specify a pin and claim its use is for a speed sensor and configure it as such in a Mach3 plug in it should work. In addition it should be supported. I will use whatever it is they had in mind that will satisfy Mach3 requirement for single pulse and Pokeys logic low. It appears they did not plan for this or I would get an answer.
Sorry for the rant. Can anyone help me to figure out what components I need to assemble to convert the analog signal to a digital one. If not, can someone tell me how to get closer to the 0v rail before I attach the signal to Pokeys board.
Attached is a photo of the machine and a diagram of my last attempt. Any help here would be greatly appreciated. I have seen others use this same sensor with Mach3 and it is why I selected it.
Thanks for looking,
Jeff K.