MCU PI discriminator

[Tinkerer]

MCU PI discriminator
I have been struggling for some time now to incorporate a MCU into my discriminating PI design.
This thread is an intent to find help by more knowledgeable people and at the same time help others who are in the same predicament as I.
Gotz von Berlichingen has offered his help. I hope others will join in.
We are beginning with the PIC16F690 because I have already tested a timing schedule with the demo board containing this chip.
However, I don’t want to limit this project to low end MCU’s, rather I would like the project to grow slowly into the higher end with USB capabilities and all other bells and whistles, so that eventually we can program our detectors from a PC, with firmware that is designed for specific tasks and environments.
It would be really nice if we could make this project not only with PIC, but also in parallel with AVR so that we could satisfy the individual preferences.

We would like to keep this "Open source" at least to the "Demo" version.
We can always consider a "Pro Update" at a later time.
Tinkerer

[Götz von Berlichingen]

Would you please post the Schematic and Code ?
It would be a good Way to get started if we see what you got so far.
What Demo Board do you use ?
I have a PicDem2, these Boards have some useful Stuff (Switches, LCD)
connected to certain Ports on the PIC.

[Tinkerer]

Would you please post the Schematic and Code ?
It would be a good Way to get started if we see what you got so far.
What Demo Board do you use ?
I have a PicDem2, these Boards have some useful Stuff (Switches, LCD)
connected to certain Ports on the PIC.

I have the "Low Pin Count Demo Board" that comes with the PIC16F690 and Pickit 2
I also have the Picstart plus that can program the 40 pin 16F877A as well as a 16F877A chip, but will have to make a PCB to use the 877.
A few days ago I posted a <Timing.pdf> file and a picture of the timing simulator somewhere on the forum. I will try to copy all the posted information over to this thread, but my Internet connection is the very slow kind and often the connection drops because of bad weather because I am in a remote area. So please be patient.
Tinkerer

[bugwhiskers]

Hi Tinkerer,

I can translate your PIC code to ATMEL if you like to give people a choice. Just a 6 pin header is required to re-program most ATMEL chips. When I see the number of pins required and the size of the code I will be able to recommend which chip to use.

regards
bugwhiskers

[Carl-NC]

If you use an 18F4550 you can reprogram it via USB from any PC. I discussed this in the CDG forum, and even designed a tiny little PCB for easily patching this chip into any design, but never got the boards made. Maybe it's time to pull the whole thing into the public domain and order some boards, eh?

- Carl

[joecoin]

I'll take 3 of those boards when they're ready.

[Götz von Berlichingen]

I have the "Low Pin Count Demo Board" that comes with the PIC16F690 and Pickit 2
I also have the Picstart plus that can program the 40 pin 16F877A as well as a 16F877A chip, but will have to make a PCB to use the 877.
A few days ago I posted a <Timing.pdf> file and a picture of the timing simulator somewhere on the forum. I will try to copy all the posted information over to this thread, but my Internet connection is the very slow kind and often the connection drops because of bad weather because I am in a remote area. So please be patient.
Tinkerer

I guess i found your timing.pdf and schematic
https://www.geotech1.com/thuntings/s...1&postcount=17
My connection is quite fast

[Tinkerer]

PIC18F4550 PCB

If you use an 18F4550 you can reprogram it via USB from any PC. I discussed this in the CDG forum, and even designed a tiny little PCB for easily patching this chip into any design, but never got the boards made. Maybe it's time to pull the whole thing into the public domain and order some boards, eh?

- Carl

I definitely would want at least one of these boards.

Here is how I see this project:

I or we learn how to walk with the PIC16F690.
Then we learn how to run with the PIC18F4550

After that we learn how to fly ...the sky is the limit.

Tinkerer

[Tinkerer]

Translate PIC to ATMEL

Hi Tinkerer,

I can translate your PIC code to ATMEL if you like to give people a choice. Just a 6 pin header is required to re-program most ATMEL chips. When I see the number of pins required and the size of the code I will be able to recommend which chip to use.

regards
bugwhiskers

This is a very generous offer.
I am sure there are as many ATMEL fans as there are PIC, so we can help all of them.

Tinkerer

[Tinkerer]

Timing.pdf

I guess i found your timing.pdf and schematic
https://www.geotech1.com/thuntings/s...1&postcount=17
My connection is quite fast

Thanks Gotz,

The project is in a very fluid development stage. On that circuit I had a switching delay of about 5us at switch off time.
Change R1 and R6 to 1k, this reduces the delay to about 2us.
This delay is not important it is being compensated in the PIC timing code.

About the PIC timing code:
It works but I need to clean it up a bit before showing it in public. I will post it soon.
Tinkerer

[Tinkerer]

Hammer Head FE discriminator MOD

I think we could make this learning project a Hammer Head FE discriminator MOD.

I have tested the FE Discrimination and it works.

Attached is a simple PIC timing file in Assembly. It functions but needs cleaning up.
Then I hope with the help of other forum members, we can let it grow.

Tinkerer

[Tinkerer]

ASM file

The ASM file did not upload, so I try.rar, does not go either, will try text

Tinkerer

[gwzd]

Hi Tinkerer,
You could do better with relocatable code instead of absolute code. The use of macros is highly recommended, it will simplify your code and make it more readable.
Regards
R.A.

[Tinkerer]

Relocatable code?

Hi Tinkerer,
You could do better with relocatable code instead of absolute code. The use of macros is highly recommended, it will simplify your code and make it more readable.
Regards
R.A.

Thanks for the input.
As you can see, I am a beginner at the very beginning. I have no idea what relocatable code is. Could you please teach me?
The problem is that every tutorial about software is always considering that one already knows the basics. Well, I don't, this is my first try and I am really feeling too old for that.
This is why I am begging for help.

I think there are others that have difficulties but are ashamed to ask for help.
Well, I am too old to be ashamed too, so I just beg shamelessly.

I will welcome any help.

All the best
Tinkerer

[Aziz]

Relocatable code = position independent code

see on wiki:
http://en.wikipedia.org/wiki/Position_independent_code

Typically, relocatable code is more compact due to smaller relative program counter jumps, which can be coded in most cases directly in the assembly code (no additional operands needed). This part of code can be placed anywhere (moveable code).
Absolute branching needs more operand code size (jump position). Code is not moveable and needs to be placed at particular address.

Aziz