[GPS_Standard] PIC18F2220 versus PIC18F2221

Fri May 21 14:24:24 EDT 2010

Hi Bert,

I have looked with a lot of detail at the configuration bits of the 2221 but 
without results. The bits that could have an impact had the correct values 
already and explicitly specifying them made no difference of course.

I have a 2220 from digikey that works fine, but it remains a question why 
the 2221 does not count. I cannot beleive that I received a bad 2221 chip.

The configuration bits give no solution and the datasheet with respect to 
the counter/timers show no difference at all between 2220 and 2221 like you 
also noticed.

Best regards,
Martein
pa3ake

----- Original Message ----- 
From: "Bert, VE2ZAZ" <ve2zaz at sympatico.ca>
To: <gps_standard at mailman.qth.net>
Sent: Monday, May 17, 2010 6:13 PM
Subject: Re: [GPS_Standard] PIC18F2220 versus PIC18F2221

>
> Hi All,
>
> I have spent some time this morning trying to see the differences in the 
> timers between the two devices and could not see any. Three of the total 4 
> timers can run in 16-bit mode and two of these 4 can run in 8-bit mode. 
> Same features associated to each of them.
>
> One difference is the Enhanced USART vs Addessable USART, which brings 
> auto Baudrate detection. But I am pretty sure the must have made the 
> EUSART compatible (by default) withy the AUSART.
>
> One area I would spend more time on is the configuration bits. Several new 
> bits were added. This is where I suggest working. One bit affects Timer 1, 
> which is the one used for the 10MHz frequency capture feature. Also make 
> sure y DO NOT invoke the Extended Instruction set (XINST).
>
> Other small differences appear to reside in the Power up reset, the 
> NanoWatt stuff, etc. These should not affect counting operation.
>
> I may order one 2221 to try it out, but this is not going to happen in the 
> near term. You will probably find the solution before I can try 
> anything...
>
> Have fun!
>
> Bert, VE2ZAZ
> http://ve2zaz.net
>
> ----------------------------------------
>> From: martein at xs4all.nl
>> To: gps_standard at mailman.qth.net
>> Date: Mon, 17 May 2010 16:45:51 +0200
>> Subject: Re: [GPS_Standard] GPS_Standard Digest, Vol 34, Issue 1
>>
>> Hi Roberto,
>>
>> I think that is an error in the datasheet overview of the 2221. I have
>> recompiled the firmware with the 18F2221 include file and I had to fix 3
>> errors having to do with different names of the configuration bits.
>>
>> Now when I use this new firmware compiled for 2221, I have exactly the 
>> same
>> result. It does not count properly. The hexfiles only differ for the bits
>> that describe the configuration bits. And that is correct that is also a
>> visible difference the datasheet.
>>
>> If you go through the datasheets of the 2220 and 2221 side by side on the
>> pages that describe the timer counter hardare, there is no difference to 
>> be
>> found.
>>
>> I am going to leave it now. I am not a PIC expert and don't want to 
>> become
>> one Hi!
>>
>> Best 73's,
>> Martein
>> pa3ake
>>
>> ----- Original Message -----
>> From: "Roberto Barrios"
>> To:
>> Sent: Monday, May 17, 2010 4:20 PM
>> Subject: Re: [GPS_Standard] GPS_Standard Digest, Vol 34, Issue 1
>>
>>
>>> Hi Martein,
>>>
>>> Now I'm not so sure... Looking at page 3 (as per AdobeReader) of the
>>> 18F2220
>>> datasheet, lower right corner, you can read "timers 8/16bit: 2/3", but
>>> there
>>> is no more info on the fifth counter, in page 10 it says this part has 4
>>> timers. Now I am not sure where the issue is.
>>>
>>> Regards,
>>> Roberto EB4EQA
>>>
>>> -----Original Message-----
>>> From: gps_standard-bounces at mailman.qth.net
>>> [mailto:gps_standard-bounces at mailman.qth.net] On Behalf Of
>>> gps_standard-request at mailman.qth.net
>>> Sent: domingo, 16 de mayo de 2010 18:00
>>> To: gps_standard at mailman.qth.net
>>> Subject: GPS_Standard Digest, Vol 34, Issue 1
>>>
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>>> Today's Topics:
>>>
>>> 1. PIC18F2220 versus PIC18F2221 (Martein Bakker)
>>>
>>>
>>> ----------------------------------------------------------------------
>>>
>>> Message: 1
>>> Date: Sat, 15 May 2010 21:47:28 +0200
>>> From: "Martein Bakker"
>>> Subject: [GPS_Standard] PIC18F2220 versus PIC18F2221
>>> To:
>>> Message-ID: <574096AB150146CFBD63DFAE3EFE9A85 at mhbp5q>
>>> Content-Type: text/plain; charset="iso-8859-1"
>>>
>>> Hi list!
>>>
>>> I have succesfully built the VE2ZAZ GPS standard.
>>>
>>> Initially I used PIC18F2221 as I could not get PIC18F2220. The 18F2221 
>>> is
>>> supposed to be the newer and better part and successor of 18F2220. I 
>>> went
>>> through the datasheets and could not see any difference that would 
>>> prevent
>>> the 18F2221 to work in this application. However it failed to work
>>> partially
>>> in practice. Montrol software could talk with it, but the measured
>>> frequency
>>> was always 0 and strange enough the frequency difference was not 0, but
>>> the
>>> MSB byte was always 0! Obviously it did not lock.
>>>
>>> Does anyone know why the 18F2221 does not work with this application? It
>>> would be great if the firmware is compatible with this device as it is
>>> much
>>> cheaper.
>>>
>>> Best regards
>>> Martein
>>> pa3ake
>>>
>>> ------------------------------
>>>
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>>> End of GPS_Standard Digest, Vol 34, Issue 1
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>>
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