Parallel Port... again!

[Menticol]

Ok I have made a diagram, I hope its correct

**broken link removed**

The thing consists of a parallel port, 74LS139, a "X" circuit for each 74LS139 output, and its respective relay.

The "X" circuit and relay should change its state when receiving the pulse from the 74LS139, and keep it while the 74LS139 actuates other "X" circuits

If I try to use the schematic without the "x" circuit, I'll be able to turn on only 1 device at time, so would be a controller with limited utility

 

[ericgibbs]

hi menticol,
The circuit you have posted, the 139 will not 'hold' the output state.
As soon as you load another address the 'old' 'X' will drop out.

EDIT:
Look at this option, each 139 controls, 4 latches.

 

[Menticol]

Hello again Eric and Mikebits!

Sorry by the delay, my job is killing all my electronics time

Thank you by your suggestion Eric, but I'm afraid it gets too expensive vs. benefit. Each latch consumes 2 pins of the decoder, so I'm gonna need a lot of cascaded decoders and latches to control a respectable ammount of devices.

I'm been studing the diagram of my 20th june post, about cascading the decoders. I understand more decoders means more A. B, C inputs, and the free pin of the second decoder is used to feed an eventual third decoder, and so on. But I cannot figure out yet.

I have found an interesting dual flip flop circuit, but multipling it times x numer of decoders, no way (even using a hex 74LS174 flip flop, stills require too much adtional components) Anyway I leave it here if anyone could find it useful.

About the LM35 interface through MCP3202, I'm very interested on it, but I don't wanna be rude (like the newbies that invade the site) asking you to do my work, so if you would like to share some clues to make my own schematic, I'll be grateful

Thank you by the EPP idea Mikebits, I'll read more about it, I would use it as a B plan if the decoder idea sinks.

edit: I found the MCP3202 datasheet! I was mispelling the name... but no typical aplication or test circuit

 

[ericgibbs]

hi,

About the LM35 interface through MCP3202, I'm very interested on it, but I don't wanna be rude (like the newbies that invade the site) asking you to do my work, so if you would like to share some clues to make my own schematic, I'll be grateful (I cant get the MCP3202's datasheet or typical application page!)

This is the inteface I use with the PC parallel port.

If you are savvy with Visual Basic, let me know if you need the VB5 program, I will pretty it up and post it.

You can get the MCP datasheet from DatasheetArchive :: Free Datasheet Search Engine :: Electronic Components

 

[ericgibbs]

hi menticol,

For latches look at the HEF4724 datasheet

Its a addressable 8 bit latch, that holds the state of the output, until over written.


HEF4724 Selling Leads,HEF4724,PHILIPS [Philips Semiconductors] Datasheet PDF

 

[Menticol]

Program exchange would be great!

Here is my program, its a simplified drawing of my room (without the dirty clothes and dirt under the bed, offcourse!). Touching the objects sends a signal trough parallel port, turning the thing ON or OFF. Based on inpout32.dll code, found on planet-source-code. Nothing complex.

My last "high technology" advance was adding a dimmer I've found abandoned on my university. The pot was broken, so I wired a resistor to it. When the relay is open, the dimmer's pot resistance is 0 so the room lights shine with full intensity. When the relay is closed, wires the dimmer through the resistor, so the light fades down. With a simle VB mp3 player, the light can be dimmed automatically if some music starts (a geek way to entertain female guests, but may be improved... maybe a solenoid driving the fireplace? hahahaha)

 

[ericgibbs]

My last "high technology" advance was adding a dimmer I've found abandoned on my university. The pot was broken, so I wired a resistor to it. When the relay is open, the dimmer's pot resistance is 0 so the room lights shine with full intensity. When the relay is closed, wires the dimmer through the resistor, so the light fades down. With a simle VB mp3 player, the light can be dimmed automatically if some music starts (a geek way to entertain female guests, but may be improved... maybe a solenoid driving the fireplace? hahahaha)

hi,
A couple of years ago I played around with voice control using the PC and the microsoft speech programs linked into VB.

Using the parallel port.

I could command the PC to play classical, pop music,etc, next track, mute, volume up/down [activeX component]. Control the TV channels, lights etc.
That was cool.

It was the lack of female guests that gave me a problem.

Look at the microsoft site for voice/speech control

 

[Menticol]

Hahaha yes! Making the PC speech is great, but never tried speech recognition (you're on the great leagues!). By the way, If you wanna equip your programs with a beautiful female voice, check this out

AT&T Labs Text-to-Speech: Demo

EDIT: They lowered the voice quality since last time I played with it but you still get the idea

 

[ericgibbs]

hi Menticol,
Attached zip file is for:

LM35 temperature sensors driving a MC3202 dual 12bit ADC, using Visual Basic5, connected to the PC using the parallel port.

Included is a circuit diagram, the VB5 program source code also the *.exe.

Its a complete package for building and running the project.

Anyone requiring more information, please ask.

EDIT: Added a screen shot.

 

[rainbow]

hi all
i have a problem with the parallel port ( exactly with status pins)

i implement an adc using (dac , comparator and a simple software of succusive approximation)
i use an lm741 as a comparator with 12v-ground.
when comparator is high output=9.8v
when comparator is low output=1.89v
this output must be connected to status through parallel port
comparator is either high or low, the status pin don t change its output,it has an output of 4.7v (for only one pin of course ).
is this because of low power from my circuit?
my circuit could not change the pin votage???
when i have connected the ground of the circuit tothis pin it changed to low
but it dont response to my comparator (lm741).......
what is my fault ....?? please it is important for my project

hint:sorry if my english is bad or there is some errors

 

[ericgibbs]

hi all
i have a problem with the parallel port ( exactly with status pins)

i implement an adc using (dac , comparator and a simple software of succusive approximation)
i use an lm741 as a comparator with 12v-ground.
when comparator is high output=9.8v
when comparator is low output=1.89v
this output must be connected to status through parallel port
comparator is either high or low, the status pin don t change its output,it has an output of 4.7v (for only one pin of course ).
is this because of low power from my circuit?
my circuit could not change the pin votage???
when i have connected the ground of the circuit tothis pin it changed to low
but it dont response to my comparator (lm741).......
what is my fault ....?? please it is important for my project

hint:sorry if my english is bad or there is some errors

hi,
It looks as though the 741 otput is not going low enough to switch the status pin low. Not a logic '0'
Do you have another comparator, a LM393 for example.????

Do not appy 9.8V to the status pin, it will damage the port.

 

[rainbow]

first thanks for replying

hi,
It looks as though the 741 otput is not going low enough to switch the status pin low. Not a logic '0'
i use a seris resistanse to have a drop on it but it didnt work the status pin is still 4.7v
Do you have another comparator, a LM393 for example.????

Do not appy 9.8V to the status pin, it will damage the port.

i did it actually but it turned to 4.7v (the original output of the status pin i use)

 

[ericgibbs]

first thanks for replying



i did it actually but it turned to 4.7v (the original output of the status pin i use)

hi,
You cannot fit a series resistor, you wll never switch off the status bit that way.

The 741 amplifier cannot switch low enough to make a logic '0'.
Inside the PC on the status line is a pullup resistor, the 741 cannot pull the voltage down low enough.
You require a LM393 comparator.

 

[Menticol]

hi Menticol,
Attached zip file is for:

MC3202 dual 12bit ADC


EDIT: Added a screen shot.

Hi Eric!

I'm having trouble getting the MCP3202. One of the store's guy (well, I asked on 10 stores) told me the difference between linear and parallel A-D converters, and how difficult is to find MCP3202 in Bogotá (almost impossible!).

He suggested me to use a parallel A-D converter (I don't remember the reference, something like ADC or 0880 8008 etc), but it's not compatible with your software and schematic, so I ignored him.

What other "linear" AD converter could be used? Maybe an older one is easier to find...

Thank you again!

 

[Menticol]

Sorry by double-posting, edit was disabled

Working with 74LS139 By now, I know how to cascade two of them

But how can I cascade 3, or more?

Thank you in advance

 

[ericgibbs]

Sorry by double-posting, edit was disabled

Working with 74LS139 By now, I know how to cascade two of them

But how can I cascade 3, or more?

Thank you in advance

hi,
Use 3 of the other output pins into a 74LS138, then use the 8 decoded outputs to select the required LS139.

The PC program was written for a SPI, MCP3202. dual ADC.

What other SPI ADC's are available locally.?

EDIT:
Can you source 74154 4 to 16 mux/demux ic's locally, they are a better option than LS139's

 

[Mikebits]

Eric, you are a nice guy, always helping peeps out. Good to know ya, don't cha know

 

[Menticol]

I agree Mikebits, thank you so much Eric!