mixing 5v and 24v on mesa cards

So I got a cute little laser tool setter, but it is 5V. Everything else on my machine is 24v.

I have a mesa 7i96s, and a mesa 7i84

Where/how would I connect this so it is happy? It needs one 5v tolerant input to read the signal, and it also needs one 5v output to enable the laser.

It seems like I could dedicate one IO row on the 7i84 to 5v, but it seems a waste of IO.



Current IO layout:

---

5 volt input  

• laser setter input (7i84)
• probe input (7i84 - just to make use of this row, it can also run 24v)
•  

  24 volt input 

• hard limit x (7i96s)
• hard limit y (7i96s)
• hard limit z (7i96s)
• home x (7i96s)
• home y (7i96s)
• home z (7i96s)
• servo alarm x (7i96s)
• servo alarm y (7i96s)
• servo alarm z (7i96s)
• spindle unclamp sensor (7i96s)
• E stop (7i96s)

   5 volt output 

• laser setter enable (7i84)
•  

  24 volt output 

• solenoid MQL (7i96s)
• solenoid tool release (7i96s)
• solenoid laser tool setter air (7i84)
• spindle forward (7i96s)
• spindle reverse (7i96s)

There will be other IO to come for the ATC. Seems I would have 16 open 24v inputs, 14 open 5v inputs, 7 open 5v outputs and 7 open 24v outputs. Plus the 2 high isolation outputs on the 7i96s. I will want an MPG as well, and there will likely be some switches and buttons and overrides but they are not decided yet.

This seem like the best way to do it? Any thoughts on a better plan? I guess I could just make some switches and things 5v that do not really require 24v.
 

Hmm. I think this will work fine. the MPG occupies most of the 5V inputs anyway. Should have enough IO left for the ATC mechanism.

 

Yeah i think its fine. my main worry was wasting all my IO, but it seems i have enough.

Another option is to use the 7I96S's parallel expansion connector for the MPG
(there's firmware that puts a second INM module on P1 so adds 4 MPG encoders
and debounced inputs)