Microcontroller use for Multiple solenoids

My name is Zack Berube, I am a Student looking for some help on a project. I am trying to control up to 175 pnuematic solenoids on a Plexiglass grid using a microcontroller. Only a handful of the solenoids will be active at any one time (maybe 30-40) I had been using a C-Rio module with 37 Digital outputs for the prototype but with that many solenoids the current draw through the Rio was prohibitive.
I have never used a microcontroller and have limited electronics knowledge. Would anyone be willing to point me in the right direction? is a microcontroller even what I want? will one suffice or will i need several working in conjunction.
Even if you just tell me a book to go read, i would appreciate it.

Regards

berube said:

My name is Zack Berube, I am a Student looking for some help on a project. I am trying to control up to 175 pnuematic solenoids on a Plexiglass grid using a microcontroller. Only a handful of the solenoids will be active at any one time (maybe 30-40) I had been using a C-Rio module with 37 Digital outputs for the prototype but with that many solenoids the current draw through the Rio was prohibitive.
I have never used a microcontroller and have limited electronics knowledge. Would anyone be willing to point me in the right direction? is a microcontroller even what I want? will one suffice or will i need several working in conjunction.
Even if you just tell me a book to go read, i would appreciate it.

Regards

Click to expand...

As far as I've seen, it's kinda of Profi Bus device, isn't it? You have not wrote what is the controlling device for your solenoids, what is the current consumption of each of your solenoids, how fast you are switching them,...

If you must use PLC system, you can 'unload' the outputs of your cRio module with transistors that will switch solenoids.

Anyhow, more info you give, more help you will get in return

Apologies - yes the Rio is a kind of Profi bus device. I am trying to figure out what i should be using to control the solenoids. Each solenoid draws 0.08a at 12v (0.96w) and at any time i will be drawing 28.8w - 38.4w max. I believe i will need a refresh rate of 1-3hz. The reason i was thinking i needed a microcontroller was because i wanted to be able to actuate any of the solenoids at any given time so i was trying to get away from the CRIO due to the limited number of outputs. I "theoretically" could add 5 more modules, at that point i could "unload" the CRio outputs with transistors. Those modules are pretty expensive so I would like to get away from that if possible.
Thanks - at this point I am so new to this I don't even know what it is that I am leaving off.

Well, 1-3Hz is easily achievable even with microcontroller. I may suggest you a controller with serial or even USB connection to PC.

Further more you will need 22 pcs. of 74HC595, 22 pcs. ULN2803, a buffer or two, some more components and, from my point of view thet's it.

Later on I'll post a kind of schematic that may help you.

As I promised, here is the idea for interfacing your solenoids with 8 bits of the uC.