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Tips and questions relating to the GPS modules from SFE
By prenning
Couple questions regarding this device.

What does the ENABLE pin do? Place it into low power mode? Turn on the receiver when a logic hi is applied?

Final question - does the ENABLE pin have to be asserted to send the device commands to change to baud rates, use binary messages, etc.?

Have read the user guide several times and can't find answers to these.


By scalegps

Based upon my previous Sirfstar III experience the pin is actually the /Reset pin. This is normally pulled high through a pull-up resistor and only pulled low when a Reset is desired. This does two things:

1. Forces a software reset which can wake up a malfunctioning processor. We normally monitor the communications flow between the host processor and the GPS. If the receiver stops responding to queries you want to force a software reset to try to regain control of the GPS.

2. Normally a reset will force the GPS back to its default settings: baud rate might change, message formatting might change, etc. In an embedded application it is very important to have this capability, and you also need to include code in your application to reconfigure the operation of the receiver to what your application expects. For instance, if your processor is expecting data at 115,200 baud and the receiver defaults to 9600, you aren't going to see much data :o