DAVEGA X Updates

What happens over 10A charge? Bms throttles? Something burns? Need additional cooling?

There’s no throttling. (I don’t believe any BMS actually does that.)

Simo has done some thermal tests.

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The xiaoxiang smart bms can throttle or cut off charge from the app, but the app is hot garbage in the first place unfortunately.
Have you got a pic of the hot part front and back? Tempted to see if a bar of aluminium with thermal pads can fit on there

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You mean it can cut the charge if the current is over the configured limit. It can’t throttle/restrict the current though. Or have I missed something?

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I tried it now, it just shuts off. Fake news from me

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Taking measures after a recent incident…

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Did you put it in on both sides? Just to be sure :cowboy_hat_face:

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And on the main box each on every side. Maybe the welcoming screen on the unit at first boot as well.
Can never be too prepared

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I wouldn’t be surprised if that was going to be my next iteration. :sweat_smile:

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19 posts were merged into an existing topic: Public chat - talk about everything with everyone

This is so fucking awesome @janpom brilliant :love_you_gesture:

PS: Fixed :stuck_out_tongue:

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Nice! You may also want to upgrade to version 4. Upgrade to v4.00 - DAVEGA

BTW, wrong tag. :wink:

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Also, the RC releases may be unstable. If you want to test them and come back with a bug report if something is not working, that’s highly appreciated. If you prefer not to be a guinea pig though, then stick with standard releases.

(RC = release candidate)

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Yeah many thanks, I just installed the Davega and I wanted to try the update-over-the-air feature :smiley: will update it to v4 before I go riding this afternoon! :love_you_gesture:

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A few displays arrived…

I wanted some customizations. I need the corners on the display PCB rounded so that it fits into the housing and I need the SD card holders removed because they are in the way of the ESP32 on the other PCB.

It’s possible to do this by hand but it’s messy and slightly tedious. The factory refused to do it on less than 500 pcs, so, after a lot of hesitation, I pulled the trigger. I wonder if I ever run out of them. :sweat_smile:

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You adopted the same philosophy than for car maintenance : having enough spare parts for 10 years ! :smile:

BTW, step by step you’re entering always more into a professional level ! Congrats !
Can’t wait to see the Davega X2 ! :grin:

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When will a davega x2 happen?

AFAIK, @janpom said he wanted to put more work on the FW.
That makes a lot of sense. He has a lot to loose by moving to a new HW version (supply chain, suppliers headache, new references to stock, multiple FW versions to manage…).
Better have a polished SW that will extract the max of juice of the current HW. :+1:

EDIT : I was kindly joking on this, not a real pressure from me (and a little private joke :wink: ).

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I don’t know. In fact, I don’t even know what X2 will be. @Pimousse has helped me design (or more specifically, designed mostly by himself) a board with ESP32 WROVER and CAN bus. He has done a great job on it and haven’t even asked anything for it. Clément, we still have to sort that out. You can’t just be giving out free labor. That’s unacceptable. :slight_smile:

At that time (several months back) I thought that WROVER (more RAM) and CAN is exactly what’s needed. Things changed a bit though. First, I figured out a way to save a lot of RAM with the v4.0 firmware where all modules are “frozen” and loading them doesn’t consume memory. This is a huge saving and makes the WROVER pretty much unnecessary. Also the WROVER is slightly bigger and more expensive than the currently used WROOM. Last, the extra SPI RAM available on WROVER has pretty slow access so as soon as you start using it, things become slower significantly.

Regarding CAN, the more I think about it, the more I feel the added value is rather low. My initial thought was that with CAN, you could connect to a BMS directly (rather than via a VESC) and then while charging, you don’t need to have the VESC on but you could still monitor the charging progress on the DAVEGA, which would be nice. The problem is that the DAVEGA then needs to be powered from something else than the VESC and it raises a lot of questions about when it should get switched on and when off and how exactly that’s done. It makes everything very complicated. I’ve been charging my board simply with the VESCs on and I haven’t had problems with it so far. I think it’s actually just fine.

Another advantage of CAN would be that it removes the UART conflict in case you have a dual VESC (Unity, Xenith) with only a single UART port and need to connect your UART remote to it.

The downside of the CAN is that it makes wiring a whole lot more complicated than UART. With UART you just plug the connector in. Done. With CAN, you have to think about where your terminal resistors are and you have to split cables. Now, many of my customers aren’t even able to figure out whether they need a 7P or an 8P connector for their VESC. The amount of customer support that would have to come with CAN seriously worries me.

Also, DAVEGA is written in micropython and CAN support is currently only available in an unofficial fork, which is not exactly what you want to rely on in your production code.

To summarize, I’m afraid the CAN doesn’t add enough value to be worth the trouble.

I currently think the next hardware iteration will actually be the same as the current design from the functional perspective. I would just like to have it more elegant, with SMD components and PnP manufacturing. Also a smaller footprint (thinner) and a better access to the USB port. Nothing too exciting. (Probably won’t even call it X2 but rather “DAVEGA X v1.3”.)

Besides that, I do actually have some more exciting ideas about changing/improving the hardware. I’ll keep those for myself for now though.

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So if I get a davega now I will need to plug in my board charger then turn it on the esc with the button to see the charging information? If I don’t turn the board on it will still charge but not display the percentage? What happens when it’s done charging/I leave it plugged in overnight? Usually my charger stops and turns green and nothing else because the board is not turn on. In this case if I turn the board on then it will drain the battery a few % then charging will restart - perpetual? What happens if my board has auto shut off after some time? I will have to change that or I will need to repress the button to see the charging information? Would there be a way to have it or a switch connected to the charging port so it powers on while charging and/or while the esc is on?