I gotten a APM 2.6 board and when it is plugged in via USB to my computer, Mission planner will be able to get all the parameters on the board.
However using telemetry via XBEE, I have ensured that both ground and air are set to 57k baud rate and they are talking to each other. This is certain as in Mission Planner, when I click connect, the MAVLINK Connection succeeded, it cannot be able to retrieve the parameters. The dialog box “Getting Params…” is just loading non stop without any progress.
Can you connect in Terminal mode and see the boot up data?
What XBEE adapters are you using to connect to the APM? I have found that some don’t work as advertised. the XBeePro board from 3DR works well. Others may need a mod to remove the level conversion circuitry. I had to do this with Sparkfun version.
I am using XBEE series 2, 2.4Ghz
The firmware I used for the Xbee is XB24-ZB Coordinator and Router.
Firstly I did not use the telemetry pins to connect my XBEE, I’ve tried using it previously but it does not even perform the mavlink connection.
So yesterday I soldered on directly to UART1 and it is able to link and get parameters i.e, it is linked and parameters are able to be retrieved
Few hours later I tried to connect them and the “getting params” is stuck there
This is what I’m reading off XCTU terminal and Mission Planner Terminal, seems to me like it is at different baud rate, but this does not make sense as I’ve check that all are using 57k baud rate otherwise mavlink connection would not have connected them
I not sure it makes any difference if you by pass the MUX. The issue maybe that the signal from XBEE adapter is too low. you made it better by bypassing the mux, but the signal level is 3.3v when it needs to be nearer to Vcc of 5V
That’s what I mean. I had to mod that regulated board to work. If I remember correctly I removed the level translating FETs. Tomorrow I’ll find my post about it or look at the board on my desk. Search DIY drones as I may have posted about Ito there.
May I clarify is my parameter for this correct because I’m not sure if this is affecting any of my telemetry setup, it is with the attachment, i got problem uploading the picture sorry.
Also I notice that my RX/TX Led from both my xbee, are not blinking as fast as my APM RX/TX Led during the connection/getting parameters, does this means that there is an issue already here?
By the way, I have tried using CLT+T on the method and yes it is connected to my device, so the problem here is with the retrieving of parameters from my apm to xbee
Sorry Bill i have went through all of your diydrones post but not managed to find any post on how you resolve the issue
Do you have any other advice in which i can do?
NOTE: Please make sure you have check that it’s not DIN/DOUT needed to be crossed, as the guide below may result is your XBEE being destroyed.
Here’s a picture of my modified XBEE explorer with highlighted removed components. I did this for supporting a RN41 Bluetooth Module and a RN-VX WiFi module that has a XBEE footprint, as the level conversion was not working as expected. I can’t remember the exact why now, but the voltage levels are two low after the conversion.
The best idea is to scope what you current have for signal levels and see what is happening, if you the problem is too low levels you should consider removing the FETs, maybe adding small inline resistor will have a better drop to the voltage. I haven’t tested this with an XBEE, so I don’t know how sensitive they are to excess voltage on an input compared to VDD.
[quote=“billbonney”]NOTE: Please make sure you have check that it’s not DIN/DOUT needed to be crossed, as the guide below may result is your XBEE being destroyed.
Here’s a picture of my modified XBEE explorer with highlighted removed components. I did this for supporting a RN41 Bluetooth Module and a RN-VX WiFi module that has a XBEE footprint, as the level conversion was not working as expected. I can’t remember the exact why now, but the voltage levels are two low after the conversion.
The best idea is to scope what you current have for signal levels and see what is happening, if you the problem is too low levels you should consider removing the FETs, maybe adding small inline resistor will have a better drop to the voltage. I haven’t tested this with an XBEE, so I don’t know how sensitive they are to excess voltage on an input compared to VDD.
I’m not really sure what do you mean by “Din Dout need to be crossed” you mean i check that the fault lies with Din and Dout then i followed your guide?
As for the fault wise, I do not really have any clue where is the fault… I have check thru several forums, mos t people faced the same problem too
Data OUT line from the XBEE Explorer needs to go to Data IN on the APM Telemetry Port
Data IN from the XBEE Explorer needs to go to the Data OUT on the APM Telemetry Port
If you are sure DIN/DOUT are wired correctly, you can try removing the level shifting FETs. And yes lots of people have issues as the simple circuit level shifting does not always work, and it’s very confusing. Its made more so in that you can only really verify you have an issue by using an oscilloscope and look at the data and the levels. Otherwise it is just guess work.
store.3drobotics.com/products/x … pter-board works well and if you need to swap DIN/DOUT, you can just by moving a switch (i’d recommend it over the XBEE Explorer as it requires no mods)
No. Tx means transmit. Rx means receive ie. DOUT to RX.
You only need one board for the airside. The link you posted is good.
You measure between GND and TX or RX. You need to make sure the levels are valid logic levels. See learn.sparkfun.com/tutorials/logic-levels
Yup I got your Dout to RX and Din to Tx
Do I measure the TX/Rx and ground from the apm board?
Can I use a digital multimeter instead of an oscilloscope? Or I have to see the signal to verify i got a logic 1.
I’ve measure using multimeter across Tx(apm side) to ground and Rx(apm side) to ground and both gave me around 5volts value
