GPS USB Dev Board

You`ve probably heard about the CP210x USB ICs from Silicon Labs, now here`s an application that uses it. The CP2102 gives us 3V TTL to a VCP (virtual comm port) over USB as well as generating the 3. 3V needed for the board. There are a couple things to note. In this setup, we do not have any ESD protection or surge supression. We are quite
GPS USB Dev Board - schematic

possibly violating some USB standards. But does it work Yep. When you configure the CP2102 this way, it can source up to 100mA at 3. 3V using its internal voltage regulator. This is perfect for our application as the PG31 needs ~40mA at 3. 3V. The CP2102 has built-in cystal and eeprom. These means you need very few external components to get it working. You can even program in your own ID string so when you plug it onto your computer, it comes up with the name of your widget! When the CP210x is attached to a computer (and it`s soldered correctly) you will see windows hardware wizard request drivers. These drivers can be downloaded from SI Labs. You can also create your own signature drivers using some SI Labs software. You can also program the internal EEPROM to reflect your own product ID and serial strings. This software is from SI Labs as well but I forget were - when someone finds it, post it here. Once the drivers are installed, the CP210x will turn into a serial com port! Yes! It`s weird to think about until you see it happen. So this USB dev board now acts like a com port on my computer. All I have to do is pass characters in and out COM 5 (for example) and I can do things over USB! No messy drivers, no protocols to think about, it`s all done in the IC. All right! One thing to note when you are using the CP210x ICs, the Linux community may scoff. SI Labs did a great job with the windows support, but a piss-poor job...

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