Hello,
Just wanted to thank Happy and Mr. Levine for the work on the GCS, it works and looks GREAT!
Happy, I have all the functions working (airspeed, target altitude, ect.) properly.
Really like the yaw instrument that displays magnetic heading, any possibility of having the mag heading data slaved to the Direction Gyro instrument?
I noticed the RSSI section in the textual instruments package. I am assuming this related to the XBee receiver. I understand what RSSI is and used for. As an example, I am receiving information that reads as follows-
RSSI: 0.39% L: 35%
Does the (L) represent signal/data packet loss?
Do I need to do anything to the 900mhz XBee receiver to transmit RSSI info or is set by default and already working properly?
Just one more question regarding the data presented in the COM Port tab.
The GPS type reads MAVLINK, I understand that is the COM protocol but could you briefly explain what the percentage reading represents?
Thanks again for helping me better understand the GCS.
Joe
Replies
I'm not exactly sure where MAVlink gets it's RSSI. I'm assuming it's a value from the R/C receiver, not the X-Bee but I could be wrong on that. The L is for Load. This is sort of a duty cycle on the APM board. I can't say for sure that it's of any use, but it's one of those variables I didn't have room for in the status box, but did have room on the new text instrument.
I'll ask Doug what the RSSI is showing and ask how to use it.
The percentage is a rough estimate of the bandwidth usage. I'm doing a very sloppy calculation on the number of characters I've received vs the baud rate. I have seen plenty of situations where this number is over 100% (which shouldn't be possible) but I assume there's some buffering going on at the serial port which I can't see.... So I use it as a rough estimation of how hard I'm pushing the data rates through. I did some testing last night with my 3 X-Bee pairs and here's what I found:
X-Bee Pro 2.4Ghz: Great at 38,400, as soon as I switched to 57,600 I started seeing checksum errors. At 115,200, unusable...but if you enter 112,000 baud on the GCS and manually compile the APM source with PORT3 baud set to 112000 (leave the X-Bee's programmed to 115,200 via the X-CTU) then you get *less* checksum errors, but they're still there. It's usable at 112,000 but not great.
X-Bee Pro 900: Great up to 57,600. I didn't see a single checksum error. I didn't test at 115,200, but I should have.
X-Bee XSC 900: Only works at 9600 baud and lower. No checksum errors at that rate. Anything higher and it's unusable.