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Re: Old BMS Software Thread

Posted: Tue Nov 10, 2015 3:06 pm
by glyndwr1998
Ok,
Tried alittle test today, just to try to see what the cell parameters were that were already setup in the master and slaves.

Firstly set the master up as a single cell.
Used command 7 to flash cell 1 led on the slave pcb, all worked ok, the visual screen showing 1 cell at 3.29v.

Connected up a single cell with a meanwell power supply to charge the cell, hopefully to see the load led flash once the balance setting had been reached. The cell got to 3.65v no led flash from the load led, got to 3.68v and bms alarmed cell high voltage.

So, send a command 6 and 13 to reset values do default, now getting serial error codes cell 1.

I'm not sure if I've damaged anything or I've messed up the settings.

Any help to get this resolved greatly appreciated.
Thanks.

Re: Old BMS Software Thread

Posted: Wed Nov 11, 2015 11:46 am
by GregsGarage
I seem to recall the system may not work correctly with just one cell connected, but I could be wrong.

You also may need to activate the charge routine in the master to test the slave loads. My own experience so far with lithium cells is they don't require daily balancing which is why my LTC6802 slaves don't have any balance circuitry built in.

Print out and study the master and slave source code, Peter did a very good job commenting it and what it does. Combined with the schematics they are the best source of documentation.

Re: Old BMS Software Thread

Posted: Wed Nov 11, 2015 1:20 pm
by glyndwr1998
Hi Greg,

Thanks for the reply.
Sadly being mechanically biased and with no programming experience at all makes it a very steep learning curve.

I do like your newer system and design.

Is there any way of getting an arduino mega to communicate with the original slave boards, so like a hybrid, using your duinomite as a master and using your old original 16 cell slave boards, that would be a very good way for me to continue, I've been wanting to learn the arduino type platform for a while now so I could maybe kill 2 birds with one stone, so to speak, learn and get this working with a duinomite or something similar.

Thanks.

Re: Old BMS Software Thread

Posted: Thu Nov 12, 2015 3:06 pm
by glyndwr1998
Hi all,

After my test with a battery on cell 1 and the bms set up for 1 cell, took voltage level to 3.68v, the max v alarm was set, I stopped the charge by switching off the power supply.
I did send a reset all slave values to default command too.

Now, I get alarm when the bms is powered up, bms alarms cell 1 serial, on home screen no cell voltage is being shown, where it was previously. D3 and d8 LEDs are alight on the master pcb.
Master version is v0.29.

Seems to be a comms error, but I haven't disturbed the wiring since it was working ok on the bench

Any ideas hot to get back on track please.

Thanks.

Re: Old BMS Software Thread

Posted: Thu Nov 12, 2015 8:57 pm
by isaac_alaska1
If you have an oscilloscope, break it out :) if you dont, an old used Agilent off eBay is gonna be way more fun/easy to use than a brand new off-brand. I have a modern 4-channel tektronix, and I never use it because my antique 2-channel mono-color Agilent (just after they started using lcd instead of crt screen) is so much easier to use.

Re: Old BMS Software Thread

Posted: Thu Nov 12, 2015 9:25 pm
by glyndwr1998
Hi Isaac,

Haven't got those tools, I'm a mechanical eng by trade, I do have good electric skills, but poor electronic skills, but it's something I've been wanting to learn for a few years now, ideally like to learn the arduino or duinomite type of code as its relatively cheap and fun.
So, scoping isn't something I've done before, even if I had one I woildnt know what the info was telling, although I'd assume YouTube is our friend for learning.

Thanks for the reply anyway. I was hoping it was a simple set up issue as it was Woking fine reading 1 cell before I took it over 3.7 v and created an alarm scenario, since then I've lost serial comms.

Thanks.

Re: Old BMS Software Thread

Posted: Thu Nov 12, 2015 9:56 pm
by isaac_alaska1
I can't remember... Is there a clear alarms button? That might be the issue. I vaguely remember something like that. Also, to answer your previous question, you very definitely can use the arduino as a master. From what I remember nothing was written to use interrupts, so it's not too complicated to get it working on arduino. Lots of work involved though, because for one thing the coding syntax is entirely different.

Re: Old BMS Software Thread

Posted: Fri Nov 13, 2015 3:32 pm
by glyndwr1998
Hi Isaac,

Ive trawled though the software and hardware threads fro a master reset switch, did find reference to a jumper reset, but doesnt seem to correspond to my version 2 master.

Its probably something very quick and simple to solve, but as with all things if you arent sure on how it works makes it very difficult to find a problem when one emerges.

Thanks again fr your help, its very much appreciated.

Anthony.

Re: Old BMS Software Thread

Posted: Fri Nov 13, 2015 11:22 pm
by GregsGarage
If you can send command 7 and the slaves light up as they should then you know the slave bus is OK.

Even if you don't know how to read schematics or programming this project will he a good start. The source code is a version of basic. If you are considering arduino then you will be learning C programming. Personally I prefer basic.

The Maximite/Micromite is also basic and doesn't require any special compilers like PicBasic Pro.

Have a look at this thread.
http://www.thebackshed.com/forum/forum_posts.asp?TID=8077&PN=1

Its a simple oscilloscope using a micromite.

Re: Old BMS Software Thread

Posted: Sat Nov 14, 2015 1:09 am
by glyndwr1998
Hi Greg,

I was getting command 7 ok before I ran the test with my hobby charger to simulate a cell charge condition.

After the test, and the master showing cell over voltage alarm condition at 3.68v I stopped the test. It was only. A test to try to learn the led condition and the bms, nothing out of the ordinary.
However, I did send a command 6 and 13 to reset to default, and since this I have been having these problems.

Now I get a serial error cell 1 alarm, cannot send a command 7 , cannot send a command 8 to interrogate the picaxe version, basically no serial comms at all to the slaves.

I have plugged in another 16 cell pcb as I had 3 from you, and with that pcb connected, and set up to read only 1 cell, the display does show cell data at the top of the screen where it wasn't on the previous pcb, but only shows 1.75v on cell voltage where the cell connected has a voltage of 3.29v.
Again, cannot send command 7 but it ides read command 8 with version v0 being shown, not sure if this is a rogue reading.

Thanks again for your replies and help.

Anthony