Hardware Piksi Multi
Check page Piksi RTK setup.
Prefer UART connection over USB, especially on the robots with moving parts. This could easily solve a "Piksi disconnected" problem that occurs often if USB port is used to connect Piksi and the on-board PC. Look for Piksi Datasheet in the main Wiki Page.
Get familiar with Xbee configuration by reading the (short) wiki page in Xbee page. You can use an evaluation XBee board to program your devices . It looks like this (do not plug P8 with a jumper!).
Ready for use configurations, tested successfully in MBZIRC 2017 and ERL 2017, are available in xbee folder. Use XCTU to connect to your Xbee and load these configurations.
GPS antenna is quite sensible to interference, especially to the one "close" to 1.5 GHz frequency (which is the GPS carrier frequency).
Behavior:
- low number of satellites (less than 4 or 5)
- low Carrier to Noise Density Ratio (C/No), which is the signal strength of the satellite (less than 30 dB-Hz)
Possible Solutions:
- Place the GPS antenna as far as possible from any other device, such as on-board computer, cameras, Piksi receiver, etc. This is probably the best thing you can do. Increasing the distance of the antenna from everything else really helps you a lot! See even Antenna Placement Guidelines.
- Avoid using USB 3.0 if possible. See USB 3.0 Radio Frequency Interference. When it is not possible, the Placement of the GPS antenna should also be carefully considered on the platform and be located as far away as possible from a USB 3.0 connector and/or device.
- Copper tape can help to block noise. You can place it below the cover of your rover.
Behavior: ROS driver outputs "Piksi disconnected".
Possible Solutions: See "Connections" section in this page.
Possible Solutions:
- Make sure the GPS antenna and Piksi are far away from possible noisy sources (i.e. Upbaord, buck converter, etc)
- Check how many satellites should be visible in your zone: calsky