Am I on the right track?

[Andy1845c]

I just completed my Inchworm lastnight. I did not order the firefly yet as I am short on cash, so I am trying to modify Nigels schamatic in the inchworm review topic to work with a PIC16F54. Don't ask me why I ordered that PIC I didn't research it much, just ordered a few with the inchworm.

What I would like, if possible is to be able to connect Nigels LED board to this. Right now all I am worried about is flash patterns with 8 LEDs. I started to redraw the schmatic with the 16F54, but quickly became stuck. I am really new to PICs.

Vss vs. Vdd - Is one connected to the +5v and one to Gnd?

Whats Vpp?

Do I have the crystal in the right place?

In Nigels version, RB6 and RB7 on the ICSP socket go to matching pins on the PIC he is using. Can I do the same?

What is the differance between the A and B pins? Will RB0-RB7 be the ones that will plug into the LED board?

I apologize if these questions seem super easy, or if I don't know what I am talking about. I just need somone to hold my hand and point me in the right direction.

 

[Pommie]

Your on the right track.

Vdd Vss.
Vdd = 5V and Vss=0V (or Ground). You could get rid of the voltage regulator and just use the 5V from the Inchworm.

Crystal positioning.
You have got the crystal right. Is it 4MHz? I believe that Nigel uses the internal oscillator in his tutorials and so you will have to change the Config bits to get this working. When you get that far, ask again.

RB6 and RB7.
If you look on your Inchworm, you will see that pins 9&10 are labeled PGC (you have it labeled RB6). This connects to ICSPCLK (which is RB6). PGC is just a shortened version of ICSPCLK. So, to answer your question, yes RB6&7 go to RB6&7.

Vpp.
Vpp is the programming voltage (about 12V). This is correct as you have connected it.

PortA and PortB.
These are 2 different 8 bit ports. You will not be able to use RB0-RB7 for LEDs as RB6&7 are being used by the Inchworm (edit: you can still use RB0 to RB5). Nigel may be able to advise here, I assume he has modified his tutorial to take this into account.

One problem you may have is that the 16F54 doesn't support ICD2 and so you will have to setup MPLAB to configure the ICD2 as a programmer and not a debugger.

Anyway, hopefully that will get you up and running.

Mike.

 

[Andy1845c]

Thanks for the reply Pommie. Its highly apperciated. I'm going to work on this some more when I get home from work. I'm sure I will be back with more questions.

 

[blueroomelectronics]

The 16F54 connects to the Inchworm with the same pins as the 16F84A, use the Hello World quick project on my site for the hookup schematic. You should with little effort be able to modifiy the 16F84 program to work on your 16F54. No debug support on the old 16F54 though, it's a classic chip though. I still have my old [SIZE=-1]Parallax ClearView 5X ICE. (a 16C54 emulator)

PS like Pommie said let the Inchworm supply your projects 5V power. Also add a 0.1uf cap across +5 & GND as near as possible to the 16F54. This will stop glitches from resetting your PIC.

TIP #2 if you can get them a 4MHz resonator is a handy thing. They usually have the caps built in.

TIP #3 try to get a 16F628A or 16F88. both have built in oscillator and the 16F88 has the debug mode. These are cheap parts too.
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