Hello,
I bought 3DR radio set V1 in 433MHz just one month before the sale of version 2 ; bad chance.
I apply the configuration define on this page : http://copter.ardupilot.com/wiki/common-using-the-3dr-radio-for-telemetry-with-apm-and-px4/
But the range is less than 20 metters. With disappointment, I put aside the telemetry to finalize my tricopter.
I went back on the problem there two weeks.
I increased the transmission power to 100mW and I learned to graph rssi, noise, distance to home, ...
The result is bad ; 25 metters ground to ground without the interferences from motors and controllers. An amateur transmission gets better results without carrier.
In attach you can see the graph of the test and the configuration.
Could you help me to have a good telemetry ? thanks a lot
Replies
try using a FTDI and change the frequency and disable ECC?
A long time ago (year or more) Tridge provided method how to determine if output of Tx isn't damaged (i. e. due to run without antenna/with damaged antenna). The case was similiar to yours. Check this forum.
Hello ;)
thank you for your message,
the method is describ here :http://diydrones.com/forum/topics/range-problem-with-433mhz-radio?i...
I have not yet applied the proposition of Trige. In this method he showed the bad quality of RCTimer antenna. I had discard this possbility because I use 3DR radio ; but your message change my oppinion.
I borrowed a 433 3DR Radio set to a friend, I just used his antenna and I did an other test of range. The reslut is better than the first test. In fact, I changed only on antenna.
Since I received this radio, one antenna makes a noise when I stirred it rapidly. At first I believed that the wire smacked against the plastic. But may be the antenna is cut.
The next week I will verify the range with a flying test, but I need to reduce the Tx power. Because the French legislation about 433 limits it to 10mw and because the tail servo my tricopter wriggles at each packet sent by the radio. I use a shielded wire but the metal shell of the servo is not grounded. I need to create a support that isolate the servo to frame.
Thank to your help, I will give you the result
Hello all :)
I plugged my pc directly to the serial output of the IMU. I got an high quality communication. So the IMU, serial cable and FTDI cable are not the cause of the problem.
Have you any suggestion to solve my problem, please ?
Try turning the antenna so it points up.
Hi mP1,
Your suggestion is interesting but an antenna has not sans. To position it you need know the directivity and diagramme. 1/4 wave antenna have no directivity and they diagrame looks like to a donets. So in theory, with this position the GPS and IMU are not disturbed and the ground station receive the same signal.
Are you agree with my point of view ?
Hi, this is not correct. Actually to optimize your communication's range, both Tx and Rx antenna should be aligned (horizontal or oblique or vertical does not matter as long as they are aligned)
There is no doubt that one or both of your antennas are bricked. You should almost be able to get a range of a few hundreds of meters, easily.
hello,
Yes, my antennas have blue stickers.