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DAVEga: Battery monitor, odometer, speedometer


What are you insane?




Ok so just a quick note:
If you experience this:

You just need to change the last parameters in the config to the following:
@janpom Thank you again for your patience and help :slight_smile:
Also my vesc cables are 60cm long and I don’t experience any problems (I’m using a hk vesc) :slight_smile:


@janpom tried 100uF cap and 90cm wire extension. Wire is very thin and un-shielded. Cap is near vesc while davega is at the other end. Seems to work fine after one short ride.


Perfect! This is exactly the kind of testing that was much needed. Thanks a lot!


It’s on… :raised_hands:
As total noob and first time arduino user i can say @janpom you github description is super clear. I didn’t have had the right usb driver installed but even those where linked in the description.
I had to modify the tissue mode a bit to get the display working, but besides it’s no as min showing something.

The only thing which is not working now is to switch between displays.
Did I forgot to enable that in the parameters?
Or is something wrong with my switches?

PPS: @janpom my smart bms arrived today. Seems like it is for 12s LiIon


@Andy87 Great! I’m glad you made it working. It seems like you’re actually not getting data from the VESC (it’s showing 0% battery). That’s the reason you can’t toggle between screens. This is actually a minor bug that I plan to fix at some point. Dave is stuck in the initialization phase until it gets the first reading from the VESC and in this phase it’s not possible to switch screens. You’re probably in the same stage as @mmaner now. You’ll want to check your RX/TX wires and your VESC UART settings (UART enabled, baud rate set to 115200).


The buttons will only work when its connected to the vesc :slight_smile:

@janpom sorry… its your awesome device. :slight_smile:


Cool! I’m still waiting for mine. I wonder what I’ll get. :smiley: The seller responded to my message and assured me they would send me the right thing. (We’re in the wrong thread with this. Sorry for off-topic everyone.)


:see_no_evil: i just realized 5min after I wrote the last post that it need to be a connection problem :sweat_smile:
Swapped rx/tx and it’s functioning.
Fault code indicator works too :ok_hand::see_no_evil:

Strange thing, I knew there is a vault on the focbox but it wasn’t show in the terminal which fault.


Does anybody know where to get some small axial electrolytic capacitors with a reasonable capacity (5V rating sufficient)? I spent quite a bit of time looking on ebay, banggood, aliexpress, but couldn’t really find anything suitable. The diameter has to be 5mm or less. The best thing I have found so far is this in my local electronics store. The dimensions are just about perfect. The 40V rating is unnecessary though. I wish there was more capacity instead. They are also a bit expensive. 17 CZK is almost $1.


Do Digikey or Aliied Electronics carry them?


What amount of capacitance are you wanting in the cap? I see 10uF ones here, or 22uF ones here. Or on they show 77 axial caps with 5mm diameter.


The mouser filters are great. I found this guy there, which is a perfect fit, if still a little pricey.


Skimmed through the last month’s worth of comments and couldn’t find an answer, so I’m wondering if there are still kits or preassembled for sale?


Currently, I don’t think so. It’s still going through the beta testing phase. Though I’m sure if you really wanted to, someone might have the pieces needed.


So I’ve been thinking about how to do the second batch. I’m already preparing for it. I’m awaiting 50 new MCUs.

It seems that many would prefer an assembled kit, but then again this is an DIY forum and I’m sure many will prefer to assemble the Dave on their own as well. I don’t want to offer multiple options since dealing with orders is already time consuming even if I make it as simple as possible. I would like to have one standard package with one price for everyone, so that I can prepare sealed envelopes to be shipped and whenever someone orders one, I just stamp on their address and take it to the post office. Also, though the untracked shipping worked well so far, many packages got delayed and people got nervous about not knowing where their package is.

With this in mind, here’s how I would like to go about the batch 2. Each package will have two Daves, one assembled and one kit. That way, everyone will get at least one functional and everyone will have a chance to build another one, either to keep as a spare or to give to a friend. Having the assembled one on hand will then provide a template and should make the assembly easier. The price will be higher, which will the $5 for tracked shipping not sound so ridiculous compared to the value of the package.

I plan to set the price at $25. This includes $5 shipping, accounts for PayPal fees and exchange rate losses (since apparently not everyone wants/manages to pay as F&F and sometimes the money paid gets converted to CZK for no obvious reasons), the costs of the parts (I’ll be adding electrolytic caps to the next generation to protect against volatile power supply that @lrdesigns has experienced, so that’s minor extra cost) and if I’m lucky there will be $1-2 left for myself, so that I can tell my wife I’m actually making money on this! :laughing:

Also, @Mich21050 volunteered to help with completing, assembling, and distributing kits for no charge, which I really appreciate, but at the same time I think it would be nice to leave some padding in the price for him as tips. He’s a young fella and I’m sure he’ll make good use of a few extra bucks.

With the displays, that will be $35 for 2 Daves, or $17.5 for one, which is quite a bit more than the $10 that I promised, but hopefully still affordable for everyone who wants one… eh, I mean, two. :smiley:

I would like to get your thoughts on this, guys.


$35 for two of these is still amazingly low for what it is. The only other option for something like this is the photon control panel, which does have more features, but that is $115.


Sounds good to me.


That is still incredibly cheap for a 2 pack. The one built and one kit is a good idea.