Am I Asking Too Much of the Prop-1?

[JesusFreak1959]

I started to put together a program for you but -- like Jack -- I don't think you have enough IO points on a Prop-1 to do what you suggest.

Hi JM.  Thanks for the comment, but it left me confused.  From the Prop1 dox and from personal experience with the card, I understand there are 8 TTL circuits (P0 - P7) that I can use to connect the following inputs:

* P0 - a manual (or other) trigger to start the show
* P1 - P4  four cylinder piston position sensors

That leaves 3 TTL circuits unused, yes?

Also from the Prop1 dox and from personal experience, I understand I have 8 outputs (OUT0 - OUT7) that I can use to drive the following:
OUT0 - valve#1 solenoid#1 (extend)
OUT1 - valve#1 solenoid#2 (retract)
OUT2 - valve#2 solenoid (high speed extend)
OUT3 - valve#3 solenoid (high speed retract)

That leaves 3 outputs unused, yes?

That's my assessment for the sufficiency of the Prop1's I/O features meeting the requirements for this project.  In my understanding the Prop1 is more than sufficient just in terms of I/O connections.  Either I've not communicated well enough in this thread and my assessment is correct, or you are seeing something in these requirements that I'm not.  Please comment.

[JonnyMac]

What you may be missing is that Px pins are connected to OUTx outputs.  There are a total of eight IO points on the baord. If you're using Px it can be an input or output; if used as an output what happens on Px is echoed on OUTx.

The attached schematic should make this clear.  IOx is the pin connected to the BS1 processor, Px is the TTL header, OUTx is the output terminal block.

[JackMan]

Like Jon stated, you're gonna run out of I/O's with what you have outlined.
Two options that I see:
1) Do away with the position sensors and program the timing to exactly what you need (if the sequence is going to be sync'd with a sound track you'll need to do this anyway)
2) Use 4-way or 5-way valves with single solenoids (this will only use 2 OUTx connections instead of 4)

[JesusFreak1959]

What you may be missing is that Px pins are connected to OUTx outputs.  There are a total of eight IO points on the baord. If you're using Px it can be an input or output; if used as an output what happens on Px is echoed on OUTx.

The attached schematic should make this clear.  IOx is the pin connected to the BS1 processor, Px is the TTL header, OUTx is the output terminal block.

OK... thanks for setting me straight.  The schematic is of some help - prolly oughta take Electronics 101.  If I'm following you on the capability and limitations of the board, the requirement for 5 inputs and 4 outputs is the dealbreaker. 

Is there any kind of a workaround?  I'm king of the jury-rig in everything else I do; I'd be open to try it if it will save me from having to buy a $100 card vs a $40 one.  I'm new to electronics programming, so maybe this isn't a viable solution, so I'm asking for advice again.  Aren't my inputs and outputs individually addressable in code?  If I've got the Prop1 code scanning for input on 5 TTL ports, what limits me from talking to 4 different output devices versus 3?  What is the limiting factor on that 5th I/O channel that prohibits having, for example, unrelated devices such as a pushbutton to start the show (input), and an output connection to a valve?   

In the event I've got to upgrade to a different controller, you recommended the EZ-8 in a reply back in April.  Does that recommendation still hold?  Since it has a switch input, does that get me the nine I/O points I need?  Thanks for the help Jon.

[JesusFreak1959]

Like Jon stated, you're gonna run out of I/O's with what you have outlined.
Two options that I see:
1) Do away with the position sensors and program the timing to exactly what you need (if the sequence is going to be sync'd with a sound track you'll need to do this anyway)
2) Use 4-way or 5-way valves with single solenoids (this will only use 2 OUTx connections instead of 4)

I can experiment with eliminating the sensors that tell me when to launch into higher speeds on the piston retract and extension.  Those could be timed and that would eliminate 2 inputs.  Thanks for the suggestion.  On #2, the secondary valves are single-solenoid types.  The primary valve that controls initial piston extension/retraction has 2 solenoids.  From what I understand, this was spec'd for the safety of my casket riders - if electric and/or air failed, the casket would lock and not fall.  Are you saying there are valves that will do the same thing using a single solenoid?  Can you recommend a manufacturer and part number?  Thanks!

[JonnyMac]

There is no work-around with the Prop-1; the language only supports eight I/O points.

With the EZ-8 you can have one start input and eight outputs; but the IO is fixed. Again: 1 in, 8 out. Period.

If you're needing more ins and outs you could go with a Prop-2 or HC-8+.  I would recommend the latter for long-term capabilities (and we're out of Prop-2s at the moment).  Yes, it costs more, but it does far more, and a new module we received from KC Oaks today allows you to create very complex shows in Vixen, dump them onto a microSD card, then play them from the HC-8+.  And if your project grows to need more than eight outputs you can daisy-chain a second HC-8+ using the built-in RS-485 coms.

Or... you can do as Jack suggested and time your outputs and re-configure your valves so that you don't have to use two outputs for each.

[bsnut]

JesusFreak1959,

Are you saying there are valves that will do the same thing using a single solenoid?  Can you recommend a manufacturer and part number?

You can contact Brian (aka "gadget-evilusion" on these forums) of Evilusions LLC http://www.evilusions.com/ who can help you find the right valve for casket prop/ride.

I have these suggestions for you if you want to use the Prop-1 that you have and your project needs 9 I/O.
1: You can use the RC-4 for your outputs, which provides you 4 extra outputs and frees up the I/O pins on the Prop-1. Since the RC-4 uses 1 I/O pin for the serial connection.

2: You can also use the HC-8+ as Jon suggested in his last post or you can connect it to the Prop-1 in it's "out of the box" configuration.
     

[JackMan]

From what I understand, this was spec'd for the safety of my casket riders - if electric and/or air failed, the casket would lock and not fall.  Are you saying there are valves that will do the same thing using a single solenoid?

No. A 4-way valve/single solenoid is gonna send air pressure to port B when there is no power to the solenoid. A 5-way valve/single solenoid will do the same, the only difference is the 5-way has 2 exhaust ports so the speed of extension/retraction can be controlled individually.

I would say your best bet with the Prop-1 would be to eliminate the position sensors and program the timing to what you need. By eliminating those inputs your programming will also be much easier.

[JesusFreak1959]

Jon, JackMan, Bsnut & Others,

Thanks for all the assistance.  Since I'm cash poor at the moment, I'll reduce sensor I/O requirements (eliminating 2 piston location sensors), and attempt to get things working w/the Prop1.  That takes me down to 7 I/O - (3 INs/4OUTs).  If it doesn't work, and I've got to bump up to the Prop2 or the HC-8+, Jon can say, "Told you so!"  ;D

There's one question that still vexes me, and if one of y'all could answer it, I'd be obliged.  What is the relationship between the INs/OUTs on the Prop1?  I come from an audio engineering background and the relationship is very important as are the routing methods.  I assumed the Prop1's architecture was similar, i.e., no input affects output unless it is told to do so, hence my design included 5 INs and 4 OUTs.  Can someone set me straight on this concept?

Thanks again!

[JonnyMac]

I assumed the Prop1's architecture was similar

You know what assuming does...  Let me see if I can clarify a bit.

The Prop-1 and Prop-2 are generic industrial controllers.  With the Prop-1 there are eight IO (input or output; but can only be in one state at any given time) points.  The 3-pin headers provide connection to the underlying processor (Parallax BASIC Stamp 1) IO pins.  Within the program we can define the behavior of a pin using a bit in the DIRS (directions) registers.

For example, you'll see this bit of code in most of my Prop-1 programs

Reset:
  PINS = %00000000
  DIRS = %00111111

The first line clears all the pin output registers. The second line sets pins P7 and P6 to input mode (0), and P5 to P0 as outputs (1).  The % indicates binary notation.  Note that the bit order is MSB (most significant bit) to LSB (least significant bit), or this order: 76543210.

The IO pins from the on-board processor, when set to output mode, provide 5v with just a little bit of current. This is fine for running an LED like on the Trainer board, but not enough muscle to activate a valve or relay.  That's where the ULN2x03 comes in.  The ULN takes the small output signal on an IO pin and translates it to a low-side switch (i.e., it switches the ground side of the circuit). Using the output of the ULN we can in fact activate valves, relays, and other medium-current devices.

You cannot assign what you normally use in the AV world to the world of microcontrollers.  And at its core, the Prop-1 is an industrialized BASIC Stamp 1 controller. In this thread you'll find links to several articles written by myself and others about programming the BASIC Stamp 1.  You won't be able to use all of the code, but a little browsing would go a long way to helping you understand the PBASIC programming language.

* http://www.efx-tek.com/php/smf/index.php?topic=595.0