Trimble IQ to PIC16F627A

Tips and questions relating to the GPS modules from SFE
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lcwengr
Posts: 2
Joined: Mon Nov 27, 2006 10:19 am

Trimble IQ to PIC16F627A

Post by lcwengr » Mon Nov 27, 2006 11:01 am

I wrote a program to read NMEA data into the onboard USART. I begin by sending a factory reset command to the IQ module then try to read one character into the uP but I get a framing error. I initialize the USART to transmit at 9600 baud and receive at 4800 baud . I purchased a SPARK FUN IQ-USB eval board and connected to my PC running with WINDOWS98 and running the Spark Fun Monitor program, it works fine but , if I initiate the IQ module with a factory reset, it quits working. Tech support person I talked to at Spark Fun would not tell me what parameters they are using to set up the IQ module. I would any help I might receive in operating the IQ module with the PIC16f627A operating at 4 mHz.

LCW

jasonharper
Posts: 312
Joined: Wed Mar 02, 2005 12:14 pm
Location: Oklahoma
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Re: Trimble IQ to PIC16F627A

Post by jasonharper » Mon Nov 27, 2006 11:33 am

lcwengr wrote:I wrote a program to read NMEA data into the onboard USART.
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I initialize the USART to transmit at 9600 baud and receive at 4800 baud .
How did you manage that, given that no PIC's USART supports separate transmit/receive baud rates?

lcwengr
Posts: 2
Joined: Mon Nov 27, 2006 10:19 am

Trimble IQ to PIC16F627A

Post by lcwengr » Tue Nov 28, 2006 8:19 am

I have a NAND switching circuit that is controlled by output bit RA1 of the PIC uP. This circuit selects which port of the IQ module feeds the PIC USART. The buad rate of the PIC USART is switched in accordance with the port input to the PIC.

LCW

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