Counter circuit used to switch an encoder chip

[ericgibbs]

Hi Len ,Sean.

I have a question about the interface with the computer. I know I am getting ahead of my self. Would it be possible to make is so that I can use the remote separately by pushing the buttons that I am using in this circuit. Then have it so that I can plug it into the parallel port and just have the "computer push the buttons"?

Lets know when you are ready to try the parport.


Len, I hope you are getting some rain 'down under'.

 

[ljcox]

Len, I hope you are getting some rain 'down under'.

We had a few drops this arvo as I was working on installing our rain water tank. But it had stopped by the time I'd put the tools away.

 

[Nigel Goodwin]

this arvo

How about a translation?

 

[ericgibbs]

How about a translation?

I googled ?

https://en.wikipedia.org/wiki/Arvo

 

[0RESET0]

Hi Len ,Sean.

Lets know when you are ready to try the parport.

I think I am getting close. Just have to get this prototype working and then figure out how to get it on a PCB. That will be a chore in it's self.

Sean

 

[ljcox]

How about a translation?

Nigel, you're obviously not schooled in Australianisms.

this arvo = this afternoon

 

[Nigel Goodwin]

Nigel, you're obviously not schooled in Australianisms.

Schooled in it?, I couldn't even spell it!

 

[ljcox]

I think I am getting close. Just have to get this prototype working and then figure out how to get it on a PCB. That will be a chore in it's self.

Sean

I suggest you keep it in the prototype form if you also want to interface it to your laptop. The interfacing will require at least one more IC.

We need to understand exactly what you want and how far the unit will be located from the laptop.

My understanding is that you want to be able to press a key on the laptop and have it advance the counter in the unit as if you pressed the "up" button on the unit. Then press another button to initiate the transmission, ie. to the fire the cracker.

Incidentally, I'm puzzled as to why you need the counter to be able to count down. I would have thought that you would only need it to count up.

I'm also puzzled as to why you need the "unit" if you're intending to use the laptop. Why not interface the laptop directly to the Tx? (the laptop can do the counting)

Then make a PCB once you have it all working.

 

[0RESET0]

I suggest you keep it in the prototype form if you also want to interface it to your laptop. The interfacing will require at least one more IC.

We need to understand exactly what you want and how far the unit will be located from the laptop.

My understanding is that you want to be able to press a key on the laptop and have it advance the counter in the unit as if you pressed the "up" button on the unit. Then press another button to initiate the transmission, ie. to the fire the cracker. I would actually like to have a program do everything for me. I would like to be able to call up a sequence, press enter to initiate it and have the computer change the code of the Tx, fire the Tx then count to the next event and repeat the process.

Incidentally, I'm puzzled as to why you need the counter to be able to count down. I would have thought that you would only need it to count up.
I need down in case some thing doesn't fire and I have to go back. I could just reset and count back up to it but that would take too long.

I'm also puzzled as to why you need the "unit" if you're intending to use the laptop. Why not interface the laptop directly to the Tx? (the laptop can do the counting)
I do intend on using a laptop but I would also like to use the unit seperatly. would it not also be easier to write the program if it only has to do three things; count, up, fire, count... etc.

Then make a PCB once you have it all working.

Once again, I am on the fence about using the multiplexing. I am both trying to find the parts that I need to do the multiplexing and I am also looking for new displays. I think I may go with the multiplexing just because it will give me more experience. Will either way make it easier to connect the unit to the computer?

Sean

 

[ljcox]

I do intend on using a laptop but I would also like to use the unit seperatly. would it not also be easier to write the program if it only has to do three things; count, up, fire, count... etc.

Yes it should be little simpler than the full box & dice. Eric??

There is no interaction between the input side and the display side. So it is irrelevant whether you multiplex or not.

 

[ljcox]

I forgot to comment on this:-

I would actually like to have a program do everything for me. I would like to be able to call up a sequence, press enter to initiate it and have the computer change the code of the Tx, fire the Tx then count to the next event and repeat the process.

I can help you with the interface, it would only need 3 or 4 ICs; but I don't have any PC Programming knowledge.

 

[ericgibbs]

I do intend on using a laptop but I would also like to use the unit seperatly. would it not also be easier to write the program if it only has to do three things; count, up, fire, count... etc.

Yes it should be little simpler than the full box & dice. Eric??

There is no interaction between the input side and the display side. So it is irrelevant whether you multiplex or not.

Gday Len,Sean,

Using a laptop to "only has to do three things; count, up, fire, count", is a wastful idea.

As Len suggests, go the hardware route, debug and get the project working first as stand alone system.
[ I understand you have fireworks demo in the near future?]

Using the experience you gain on operating the system,
come back to us and we will help with a PC parallel port interface to the system.

Regards.

 

[0RESET0]

Alright, I will refrain from thinking about the interface until I have gotten this unit working. I was only trying to make sure that no part of the current circuit would make a difference when we finally started the interface.

I have not had a chance to pick up any parts yet. I was going to have next week off but will now be working. This makes it hard to get to our local electronics store. I will try to pick up the parts this week and finally get the prototype finished.

Sean

 

[ljcox]

Alright, I will refrain from thinking about the interface until I have gotten this unit working. I was only trying to make sure that no part of the current circuit would make a difference when we finally started the interface.

Sean

The computer interface will require another IC such as the 74LS06 or 74LS07.

 

[ljcox]

In my post yesterday, I forgot about the output interface, ie. the interface between the counters and the Tx.

You will need 2 more 74LS07 ICs for this.

 

[0RESET0]

OK, so that is (3) 74LS07 or (2) 74LS07 and (1) 74LS06? I just put in an order for three new displays. I will go back and see if I can add to the order.

 

[ljcox]

OK, so that is (3) 74LS07 or (2) 74LS07 and (1) 74LS06? I just put in an order for three new displays. I will go back and see if I can add to the order.

Sean,
You need two 74LS07 (hex non inveriing buffers) for the interface between the counters and the Tx.
Eric,
Does he need an inverting buffer of a non inverting one for the computer/counter unit interface?

What default levels are present on the parallel bus from the computer if no software that uses the parallel port is active?

What I have in mind is that, we want to be sure that his fire works won't fire immediately he connects the computer. So the output of the buffer must be high (ie. open circuit since they are o/c collectors) when the unit is plugged into the parallel port.

 

[ericgibbs]

Sean,
You need two 74LS07 (hex non inveriing buffers) for the interface between the counters and the Tx.
Eric,
Does he need an inverting buffer of a non inverting one for the computer/counter unit interface?
What default levels are present on the parallel bus from the computer if no software that uses the parallel port is active?

What I have in mind is that, we want to be sure that his fire works won't fire immediately he connects the computer. So the output of the buffer must be high (ie. open circuit since they are o/c collectors) when the unit is plugged into the parallel port.

hi Len,
Read your PM.
Its optional, [non/inv] whatever suits the rest of the firing logic devices
The logic sense can easily be set within the PC program.

As Sean will use it sometimes without the PC connected to the interface, as long as the firing logic see's a 'non active' state, any state you choose is OK. The default state of the port pins are mostly high, I could use these pins within the program.

Do you require any info on the PC's parallel port?

 

[ljcox]

hi Len,
Read your PM.
Its optional, [non/inv] whatever suits the rest of the firing logic devices
The logic sense can easily be set within the PC program. Yes I know, but that is beside the point.

As Sean will use it sometimes without the PC connected to the interface, as long as the firing logic see's a 'non active' state, any state you choose is OK. The default state of the port pins are mostly high, I could use these pins within the program. See below.

Do you require any info on the PC's parallel port?

Eric,
To clarify my point - if Sean were to plug the parallel port into the unit before the firing programme was opened, ie. the port is in its default state, we don't want the unit to advance its count or send a Tx signal to the Tx.

So if the default states are mainly high, then he will need a non inverting buffer, ie. a 74LS07 since the inputs to the unit will be active low.

Sean,
If Eric confirms the above, you will need three 74LS07 ICs.

Two for the counter output interface and one for the computer interface.

 

[0RESET0]

Just for reference, I have taken a picture of the breadboard as it sits now.
**broken link removed**
It still has my old display. I moved some things around to get more room and it still works. right now only the ones digit is hooked up. I have hooked up each digit to it's respective decoder and they are all working correctly.

It looks like I will need to get another bread board to have room for the other three ICs that I need for the interfaces. I will wait until Eric has reported in on the IC I need for the computer interface. I should have my new displays by then and have the circuit ready for the interface circuits.

Until next time...
Sean

P.S. I should have asked this before. Will I be able to run this circuit off of the same battery as the transmitter or should I plan on a separate power supply?