Blew away beforehand.
8 Likes
This looks pretty good to be honest. Probably less than 24 hours to bring a very it if balance pack back into balance is quite reasonable.
I’m going to try and get my firmware updated tonight so that I can connect mine up to a pack soon and get testing.
8 Likes
0.5 HW is pretty much ready.
Proto boards for it are gonna be ordered on 1st of February (hand assembly sanity check boards).
I’ve checked out a couple of local accounting firms that I will get in contact with later this week. I’m planning on turning my trade name company into the llc. with a name change along it. Once I get that done I’ll start contacting PCB fab + assembly houses for quotes and start making decisions on the first zero batch production run. Running alongside that I’m gonna be doing my hand assembly boards.
I’m not quite sure how the CAN-bus will behave if you have multiple devices (>2) on it and multiple of them have termination resistors. Normally the termination resistors are only used at the end of the cable chain. So just in case I moved the termination resistor a little bit on the board and added an easily cuttable open trace, so if there is too much termination on the bus, you can just cut that little trace to disconnect the termination resistor and solder bridge it back on later if it’s needed.
15 Likes
Wouldnt hdd jumper be easier solution for that?
Wouldnt hdd jumper be easier solution for that?
If the majority of users don’t need to change the termination then it’s easier for manufacturing to make it configurable by cutting a trace.
I suspect electronics nerds think absolutely zero of slicing a trace or soldering a jumper if they want to go back.
for non electronics nerds cutting the trace would be easy too. going back might would require soldering. and yes a jumper would be easier for that. but most people won’t need to switch back and forth.
so I think on the whole with all aspects considered including manufacture, easier is the cut-able trace.
an opinion.
2 Likes
I have two VESCs and DieBieMS interconnected via CAN-bus and it’s working fine. I suppose all of them have termination resistors. I believe it’s not too uncommon to connect four VESCs via CAN-bus for 4WD. Maybe this isn’t a problem?
2 Likes
Got it. Just my opinion.
Only possible CAN termination on the DieBieMS is the R69 resistor. I guess it has a 120R populated on it on the board?
I’m probably gonna get to design some military tech at work… Cool…
1 Like
What about a solder joint ? Too big ?
EDIT : I used this tip for my SmartCharger
Unsoldered : no termination resistor connected
Soldered : 120R termination resistor connected
(I’m wondering about adding a transistor for a SW switch in a future version)
1 Like
I left an uncovered trace at the other end of the termination resistor, so it’s connected by default. The trace can be cut, if it needs to be disconnected and there should be enough trace left, so you can solder bridge it later if need be.
On Focbox Unity i add a 4,7ohm 1w resistor on 5v canbus cable for 2 unity on 4wd to make it work safe
5 Likes
You put it on the 5V rail? Interesting…
I suppose the GND is already referenced via the battery packs themselves?
Then it would seem that the DieBieMS comes without CAN termination resistor. Probably works fine, because of short cable lengths.
Considering the following setup :
- Dual VESC 6 or similar
- DieBieMS
Then, both bus ends are both VESC as they embed a 220R termination resistor.
So the DieBieMS acts as a node on the bus.
That’s fine.
3 Likes
I think this resistor on the 5v of the the unity CAN connection is so that one switch can be used to power up both unitys via the can connector. I don’t this is related the the CAN operation in any way.
5 Likes
Yea you are right. Forgot about this
4 Likes
One question regarding the pcb design, and it’s not only for this creation, but for all the pcbs where one has chosen to solder a xt60/90 connector directly to the pcb itself.
Why not extending the pcb so that it gives mechanical support under the connectors? This would lessen the risk of connector breaking off the solder pads from vibrations as one could reinforce the xt60/90 to the pcb with glue. Seems a lot more reliable to me.
1 Like
Does that mean that DieBieMS with only one VESC wouldn’t be ideal?
Usually there’s not a problem if termination isn’t exactly correct if there aren’t to many units on the same bus, try to keep the cables about the same length if not terminated correctly. I’ve had to terminate incorrectly sometime because the bus cables have had massive difference in lenght (not e-skate related)
2 Likes