The internal oscillator is perfectly fine at 9600 baud, and actually well above that - however, for absolute reliability I always stick to 9600 baud - which is usually more than fast enough anyway.

__________________
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I should have rephrased that - the combination of the internal OSC and PLL enabled has been known to make UART unreliable

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Spency.

PIC Micro's - Your mind is the limit

PIC's and interfacing with other devices - a PIC Basic Guide @ digital-diy.net

 

Its not static unless all my 18 chips are bad.


- Are all Vdd and Vcc pins (2 of each) connected to their respective supplies? yes

- Do you have the 0.1uF tantalum capacitor mounted as close as possible between a Vdd and Vcc on the PIC?
I do have one but its not as close as possible, it is less than 1" away on my board. However this works fine with an A3 chip.

- Is your Crystal correctly loaded (what value caps are you using with your crystal?)
15pF

 

In that case, I guess you have found a piece of information that should be in the ERRATA for the A5 wafer of the18F4550

Try contact microchip about it, and see what their response is

Luckily enough you had other chips to try this with and isolate the problem, I salute you for your perseverance!

__________________
Spency.

PIC Micro's - Your mind is the limit

PIC's and interfacing with other devices - a PIC Basic Guide @ digital-diy.net

 

I really hope that is the case because I'm about to start pulling my hair out.

I have been in contact with Microchip and still waiting for their conclusion. I'll post here if I find anything out.

 

Microchip doesn't want to listen!

They believe that since it passes a loopback the chip is fine. Even though when connecting 2 pics together via usart A5 to A5 works fine but A5 to A3 does not. This explains why it passes the loopback but geeze.....

 

Can you post your schematic? Are you running on 5V? Which wi.232 module they make quite a few.

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

 

http://i140.photobucket.com/albums/r..._schematic.jpg

The wireless module is the Wi.232-DTS.

The pic is running on 5v, the module 5v but there is an onboard 3.3v reg that goes to the module.

The module is not the problem as I can remove it and place a TTL shifter on the usart lines and display the same thing on the PC terminal. As I understand it a level shifter is only needed on the receiving end. Since I am transmitting a schmitt trigger buffer is not needed.

Receiving is performed by a wi.232USB base station or a TTL shifter that I got from sparkfun. The results are the same from both.

Great looking site Bill!

 

It's a little tough to tell from the schematic but what is R1 for? (on the I assume regulator IC2)
Are you using a wi.232-DTS standalone module 3.3V only or the developers kit?
Note after reading the errata sheets they have changed one bit on the ESUART for rev B5, I'm willing to bet your compiler doesn't support it properly.
http://www.microchip.com/stellent/id...cName=en010300
And thanks for the comment about my site

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

 

IC2 is a 5v reg and r1 is a ptc fuse.

Im using the wi.232DTS eval board (Ive got both the FCC and non FCC versions). It contains header pins and a 3.3v reg for the wi.232. Here is the page: http://www.radiotronix.com/products/...asp?ProdID=197

Im using mplab v7.5 and c18 v3.02

Edit: After reading that data sheet this really seems like the issue! From the datasheet:

"One bit has been added to the BAUDCON register and one bit has been renamed. The added bit is RXDTP and is in the location, BAUDCON<5>. The renamed bit is the TXCKP bit (BAUDCON<4>), which had been named SCKP. The TXCKP (BAUDCON<4>) and RXDTP (BAUDCON<5>) bits enable the TX and RX signals to be inverted (polarity reversed).

All engineering and production devices of silicon revision B4 or later have the added functionality. The RXDTP bit is not implemented, and the SCKP bit has no effect in Asynchronous mode, on all silicon revision A3 devices."

Thanks a ton for mentioning this bill. I will upgrade tonight and let you know how it goes. Upgrading my compiler was the last thing on my mind.

 

Ok so for the errata. How you fix the errata if it says workaround: none required? I have been looking at the B series however. They dont seem to have an errata for the A5...

I've upgraded to c18 v3.12 and mplab v7.6 and still the same problem.

 

I have been able to get the characters transmitting correctly!!!!!!!!

No bugs, chips are good.......I do not understand why but it seems to be related to code. Specifically this:

baudUSART( BAUD_IDLE_CLK_HIGH &
BAUD_8_BIT_RATE &
BAUD_WAKEUP_OFF &
BAUD_AUTO_OFF
);

I removed this line and it worked fine. Both A3 and A5 chips seem to work fine with this line removed. Any ideas on what this line did that caused problems?

 

Check the code it produces?.

__________________
PIC programmer software, and PIC Tutorials at:
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