Integrating the 10 Htz Adafruit ultimate gps on the dragonboard410c


#1

Hi everyone!

I was wondering if anyone has been able to integrate an external GPS with the dragonBord410C? I know it has an inbuilt 1htz GPS but for my purposes I need to have a 5-10htz gps, I have been trying to work with the Adafruit ultimate GPS as shown here: https://www.adafruit.com/product/746

I haven’t been able to access the NMEA data using a simple tx-rx connection with the dragon board. Also note that I use Android on the dragon board and I want to pass the NMEA data into an app that I will run on Android. I have been successful in retrieving GPS data and displaying it on the Android app running on the dragon board by using an Arduino board as an intermediate. But I feel like the Arduino is unnecessary given that the expansion connector on the dragon board has TX-RX pins.

Also I have tried using a 10 htz bluetooth GPS connection to do the same and it works perfectly fine but for my purposes I need a GPS module that is wired into the board and doesn’t use wireless communication to transfer GPS data. (For reference I used this bluetooth GPS which works great: http://www.qstarz.com/Products/GPS%20Products/BT-Q818XT-F.htm)

I would love to know if anyone has been able to retrieve 5-10htz external GPS data with Android running on the dragonboard without using bluetooth or an intermediate board such as an Arduino or R-pi? If so, would you please guide me on how to do it?


#2

I can’t offer you any direct experience but you’re quite right that it should not be necessary to use a micro-controller to mediate. However you do need to put something between the 3.3v GPS module and the 1.8v LS connector on the board. Before the sensors and uart boards were built I used SparkFun shifter modules to shift the 96boards UARTs but pretty much any shifter is OK. In fact if you don’t need to send any commands to the module a simple voltage divider network would probably work to connect GPS TX to LS-RX!

On the software side LS-UART0 (a.k.a. /dev/ttyMSM1) should be free for you to use. At power on, I think the GPS module doesn’t need any commands sending to it. Instead it should be constantly sending you updates (?at 9600 baud?) so you just need to fire up a terminal emulator. I’d probably recommend experimenting with Debian first to make sure you have the hardware connected correctly and then switch back to android. It’s so much easier to apt-get a terminal emulator on debian :wink: .