Maximum Operation Frequency?

[Andy1845c]

I'm looking at the datasheet for the PIC16f54. it says "Maximum Operation Frequency - 20MHz" - does that mean I could use a 12MHz crystal to get somthing up and running? I'm trying to sub the 16f54 for the 16f84a in the inchworm "Hello World" jumpstart. He's uses a 4MHz crystal, but I don't have one (that I have found so far..) But I do have what I am pretty sure is a 12MHz. How critical are the decoupling cap values?

 

[Sceadwian]

Not sure what the Hello World program uses for it's output, but if it's an RS232 out then you'll have to recalculate the baud rate for the new crystal value. Basically three times the 4mhz value.

 

[Nigel Goodwin]

I'm looking at the datasheet for the PIC16f54. it says "Maximum Operation Frequency - 20MHz" - does that mean I could use a 12MHz crystal to get somthing up and running? I'm trying to sub the 16f54 for the 16f84a in the inchworm "Hello World" jumpstart. He's uses a 4MHz crystal, but I don't have one (that I have found so far..) But I do have what I am pretty sure is a 12MHz. How critical are the decoupling cap values?

PIC's work on anything from DC to their maximum rating (and usually above it as well), for a 12MHz crystal select HS in the config fuses.

As suggested you will have to recalculate anything that's time specific, and the tuning capacitors aren't at all critical - I just use anything to hand between 10pF and 33pF.

 

[Andy1845c]

Cool! Thanks guys. Now as soon as my USB/Serial cable comes in the mail I should finally be able to flash my first LED via a PIC!

 

[blueroomelectronics]

Just make sure you select HS as the for the oscillator option. A config value of 0x0FFE should work for the 16F54

_CONFIG 0x0FFE

It's also possible to use simply a resistor and a capactor as the clock. Thats what the RC clock is for. PICLIST describes the RC clock here.


I like the old 54, it's a really simple PIC and really old now. Thankfully most modern PICs now have an internal osc option.

 

[Andy1845c]

Thankfully most modern PICs now have an internal osc option.

lol, yeah, now I have learned that I wish I would have know when I ordered some PICs to play with.

My serial cable came in the mail today, so, with any luck, i'll have somthing up and running tonight.

 

[blueroomelectronics]

If you can get your hands on a 16F88 you can play with the debugger, it is a complex chip compared with the 16F54.

 

[Andy1845c]

Well,..... its not working I'm trying to run William's Hello World program, but I can't seem to connect to the inchworm.
This is what I get

Connecting to MPLAB ICD 2
ICD0021: Unable to connect with MPLAB ICD 2
MPLAB ICD 2 Ready

I am using a USB to Serial RS232/DB9 9-PIN Converter Cable.
I have COM PORT set to COM 1 - is this right? What is COM 1? I have 4 USB ports on my computer, are they all the same or will only a certin one work?

I hope I'm just making a simple mistake on somthing and I didn't solder somthing in wrong on the inchworm.

Anyone have any ideas? ........

 

[blueroomelectronics]

Well,..... its not working I'm trying to run William's Hello World program, but I can't seem to connect to the inchworm.
This is what I get

Connecting to MPLAB ICD 2
ICD0021: Unable to connect with MPLAB ICD 2
MPLAB ICD 2 Ready

I am using a USB to Serial RS232/DB9 9-PIN Converter Cable.
I have COM PORT set to COM 1 - is this right? What is COM 1? I have 4 USB ports on my computer, are they all the same or will only a certin one work?

I hope I'm just making a simple mistake on somthing and I didn't solder somthing in wrong on the inchworm.

Anyone have any ideas? ........

Did you download the OS to the inchworm? Also make sure the FIFO buffers are off.

 

[Andy1845c]

I have it set to auto download the correct OS. Is there a way to make sure its working/manually do it?

I did turn off FIFO buffer.

Any other ideas?

 

[Andy1845c]

It seems like no matter what I try it can't connect....

ICD0021: Unable to connect with MPLAB ICD

When I try to select Download ICD2 Operating System from the Programer menu, the only file that shows up is ICD07010400.hex, and when I try it, it can't connect and fails

 

[blueroomelectronics]

What brand of USB to RS232 adapter is it? Can you tell if it uses the PL2303 chipset? (If so look on my download section for a working PL2303 driver)

 

[Andy1845c]

I can't find any info on the chipset. I can't get any drivers to install either...... After downloading the one off your site, should the windows hardware wizard find it and install it? I can't get it to, and can't get it to manually install either Nothing is going right tonight.....

I appreciate your help though! Inchworm tech suppoert is top notch

 

[blueroomelectronics]

There is usually a driver cd with the adapter. What brand is it? Right click on my computer / properties / hardware look for the comm adapter and it will tell you the chipset.

The PL2303 is only for a PL2303 USB / Serial bridge.

 

[Hero999]

A hello world program for a PIC?

Wouldn't that be quite complicated, as you'd need a dot matrix LED display?

I would think you probably mean the PIC equivalent to a hello world program, i.e. a simple tes program to show it's working. I suppose this would be something simple like flashing an LED.

 

[Andy1845c]

Yep, it just blinks a single LED. Look on blueroom's download page, its all on a great PDF poster.

I'm gonna give my cable another try tonight when I get home, I'll post if I get it working.

 

[Andy1845c]

Just an update, no luck yet

This is the cable I have: **broken link removed**

I did find a mini CD with a bunch of drivers on it hidden in the cardboard card it came on (after I dug it out of the trash) I'm not 100% sure what driver i'm supposed to use. I tried downloading the one thats on the ebay page, but that didn't seem to install right.

I'm going to get a freash Windows install and try everything over again. My home comp is really getting bugged up.

Oh, no luck finding the chipset either, I must be blind or somthing. I'm assuming its in the hardware list someplace? If I click properties where it shows my cable, sould it be there somplace?

 

[blueroomelectronics]

That sure looks like the one I use. Try the driver, you'll have to force windows to use it.

 

[Sig239]

It seems like no matter what I try it can't connect....

ICD0021: Unable to connect with MPLAB ICD

When I try to select Download ICD2 Operating System from the Programer menu, the only file that shows up is ICD07010400.hex, and when I try it, it can't connect and fails

In MPlabs you need to go to configure->select device-> then choose the 16f877 (this is the device on the inchworm that you are trying to download the OS to). After you do this, the proper hex file will show up when you try to download the OS to the Inchworm. By default MPLabs has a different device selected, so when you try to download the OS, the wrong hex shows up. This was talked about in another thread. https://www.electro-tech-online.com/threads/inchworm-components.26878/?highlight=inchworm
I even got a free firefly board for the find (Thanks again Bill!)

 

[Andy1845c]

Sig, thanks for the tip! I'll give that a try as soon as I get MPLAB reinstalled. I had it set for the pic I was trying to program, not for the one on the inchworm.....