I’m looking for some guidance as to how the Venus GPS module should be wired up. My plan is to connect this to a FEZ Domino, I suspect I’ll be using one of the COM ports.
The problem is I don’t have any datasheet that describes what the various pins are used for. Some are self explanatory (Tx/Rx/VBAT/GND), but others I have no idea how they should be connected (if at all). For example, there’s a CLK, is this a clock in or clock out? What is it used for?
In general can someone provide an example of “here’s how you wire it up”?
Hopefully, you’ve got this figured out, but if not, here is what you need to do:
Vcc: connect to a 3.3V power source
Gnd: connect to the GND terminal of the 3.3V power source
Rx: connect to the Tx pin of your micro
Tx: connect to the Rx pin of your micro
Vbat: connect to the Vcc pin
The I/O levels of this module are 3.3V TTL, so you can connect them directly to a micro powered at 3.3V. The micro should be powered (Vcc and Gnd) from the same source as the GPS module. The Vbat terminal must be connected. If connected to Vcc, the module will need to ‘reorient’ itself on every power up. If you connect a battery to this terminal, acquisition of satellites will occur faster at power up based on prior satellite (ephemeris) data.
Before you connect the module to a micro, I’d use a level shifter to connect the module to the serial port of a PC and view the asynchronous NMEA data with a terminal program!
If you look at the schematic on the Sparkfun site, it shows the CLK signal on the SPI connector so it is an SPI clock. The SPI interface of the Venus chip is for direct connection to a SPI memory chip for data logging. There is a link to the Venus chip data sheet on the Sparkfun website also.