Low cost receiver
Prototype
pg. 5
Low-Cost SBAS Receiver Design (SkyTraq Venus 838) - 25/02/2020
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3.3.2.
HC-06 Connection
The SkyTraq Evaluation board can now be
connected to the HC-06 Bluetooth module via the
header pins. As you can see in the diagram to the
left, there are 4 jumper wires connecting these two
components.
The components should be connected as follows:
•
SkyTraq Pin 2 -> HC-06 VCC
•
SkyTraq Pin 8 -> HC-06 GND
•
SkyTraq Pin 16 (RX) -> HC-06 TXD
•
SkyTraq Pin 18 (TX) -> HC-06 RXD
Try and ensure that these connections are stable
and will not pull themselves free under vibrations
from regular use.
You should now be able to plug the USB A from the
Adafruit PowerBoost 1000 into the MiniUSB on the
SkyTraq Venus 838 board. Toggling the switch
should cause the LEDs on the SkyTraq to illuminate.
The next step is to allow the SkyTraq and HC-06 to
communicate.
3.4.
Configuring the SkyTraq output baudrate
The HC-06 Bluetooth module comes with a default baudrate of 9600. To function correctly, both the HC-06 and the SkyTraq
must be set to the same baudrate. It is a much simpler task to alter the baudrate of the SkyTraq than the HC-06, so that is
the recommended method.
To alter the SkyTraq baudrate, you will need to download some drivers and an application to a PC.
You can find the USB drivers here:
https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers
And you can find the configuration software / data viewer here:
http://navspark.mybigcommerce.com/content/GNSS_Viewer.zip
Once you have installed both of these, it is advisable to restart your PC.
Once restarted, try connecting the SkyTraq directly via USB to the PC, with the HC-06 module RX and TX disconnected from
the SkyTraq header pins. Having these pins connected can cause issues when attempting to interface with the board until
the baudrates are matched. You should see the SkyTraq appear in the ports (COM & LPT) section of Device Manager. Note
the COM port number that this is connected to. If you are unsure about which device is the SkyTraq, try disconnecting and
reconnecting the device, and note which device appears in Device Manager.
Once you have opened GNSS Viewer, you will find a section in the Top-Left corner with a drop-down list for COM ports, and
a drop-down for baudrate next to it. If you are unsure about either of these values, the software has a feature to Scan Port
or Scan Baud, which will iterate through until it finds the correct port and baudrate. If you know the COM port number, enter
that here, and press the “Close” button to open the connection. If this has connected p
roperly, you will see some data in the
“Message” and “Response” sections of GNSS Viewer. Now navigate to the “Binary” drop
-
down menu and select “Configure
