CAN Bus connector

[ianwood]

I am dropping in my OSD and trimming some fat at the same time. The CAN bus connector, cable, case for the OSD are ridiculously robust and probably worth at least a few seconds of battery life. So, I am taking out the stock CAN bus connector on the landing gear and hard wiring it to the OSD which will be under the hood.

The only thing that has me a little concerned is the 280ohm resistor on the CAN-HIGH line. I think this is a termination resistor that bridges to CAN-LOW when powered up with nothing else connected to it. That is how CAN termination should work best I know. Can anyone confirm this? I am also assuming that the OSD has it's own internal CAN termination and so this resistor would serve no purpose with the OSD connected.

 

[Ksc]

is it really worth it for a few seconds of extra flight time?

 

[ianwood]

The wiring is heavier than the OSD itself. And shorter wires make for less potential for noise interference. Anyway, I did my research and found that the resistor is indeed most likely a termination resistor which is only needed if there is nothing else in the chain. Stripped it down and soldered it directly. Works perfectly and there's less clutter.

 

[Ksc]

but now you have to crack it open every time there is an update to the mini iosd.

 

[ianwood]

but now you have to crack it open every time there is an update to the mini iosd.

I honestly didn't think of that! But hey, I'll happily crack it open if the update is worth it.

 

[monoi]

Less clutter is always a good thing. I too will put the miniOsd inside, but I am more weary about cutting wires.

Is it that simple?

 

[ianwood]

Less clutter is always a good thing. I too will put the miniOsd inside, but I am more weary about cutting wires.

Is it that simple?

The CAN bus connection has four wires, V+, CAN-High, CAN-Low, GND. You can cut the gray CAN cable and the OSD CAN cable and splice them together as long as you match up the wires properly. On the OSD, open it up, cut the CAN cable at the desired length and then you can simply pull off the remaining outer layer of the wire. You'll be amazed at how light the OSD feels without most of that giant cable.

http://www.djiguys.com/Forum/viewtopic. ... 4&start=15

There are more pictures in this thread which will help. I also copied from that thread the idea for mounting the VTX inside near the vent alongside the battery. That way, both OSD and VTX are tucked away inside with only the antenna and the gimbal underneath.

 

[monoi]

Cool, thank you.

I had a look at the miniosd, it comes apart easy enough.

I just realised that the can wires from the existing plug are all grey...how do you figure out which is which?

 

[ianwood]

Cool, thank you.

I had a look at the miniosd, it comes apart easy enough.

I just realised that the can wires from the existing plug are all grey...how do you figure out which is which?

Yes, you can't go by color but if you look closely at the link in the post above that I provided, you'll see the pin out for the connector and the iOSD. Everything you need is there. Match like for like and then double check just to be sure and you're good to go!

 

[monoi]

There is indeed the required picture. Thank you.

I won't be as radical as this guy, the fpv stuff is in the post so there will be some tinkering soon.

 

[CharlieMac75]

What type of connector is that that plugs into the CAN header on the board? I have been looking for a while with out luck. Any help is appreciated. Great site. Thanks.

 

[Ravecreative]

I think it's a micro jst. Can't be sure though.

 

[JerEl]

Thanks for the good idea, it'll save me the $19 for a new CANBUS cable.
Like you I wasn''t sure that it was okay to hook it direct since on that little circuit board attached to CANBUS cable (it is removable) where you connect the iOSD has 4 tiny pins heat-pressed/soldered to the board and they come loose easy. Trying to solder that tiny pin back is impossible for most folks including me.

I would highly recommend for any one who uses the CANBUS unmodified to hot glue (or some other glue) the base of those pins to keep them from breaking loose. Mine was working fine, then one day I went to fly and had no video and finally traced it to that small connector on the iOSD. The loose pin was still in the iOSD connector.

I think this is poor quality control from DJI as none of the pins are soldered well. With all the vibration going on in the copter it would seem they would make that connection more robust. :x