Old BMS General Thread

[boelle]

i might ask stupid, but was the master able to output to an 4 line LCD display? would like that as an option if possible

[boelle]

just tried to load the master software in the programming editor.... got this one when pressing simulate:

Code: Select all

symbol Discharge    =   w7 ;w7  Global (b14,b15) = Accumulated Discharge current for last minute
                        ^

Error: Unknown symbol - w7

[GregsGarage]

Hi Boelle,

I'll try and answer your questions about the master as Peter is away on holiday. It is possible to use a lcd display or the small tv display but not both since they use the same output on the picaxe. I don't believe the software as it is written will work on the lcd display so you would need to do some coding to get it to work.

Regarding the error in the simulator, I haven't tried running or even building the master board, but there is a known issue when loading the slave software in that the editor doesn't seem to handle comments correctly in the code. You could try and make a copy of the program with all the comment lines removed and see if that helps, beyond that I don't know, it may be that the software will need to be run on an actual board instead of a simulator. As far as I am aware the master still isn't fully implemented, but Peter will have to update you on its status.

Greg

[boelle]

thanks

the simulate run was just for fun... what i will use peters design for is to make a BMS system for a Citroen Saxo... just need to get the money for the saxo and cells

[retepsnikrep]

Thanks Greg for helping there. Amazingly In Shetland on the far western edge miles from anywhere my T-Mobile usb dongle works at 56kbps! So I'm still in touch.

Have you set the editor to 28X1 mode, that error looks like you havent.

The Master could support the 2 line lcd or a 4 line one if it can be driven in the same way. But I have worked on the Master soley for the mini lcd tv monitor type display for many months, so you really need to get a mini tv monitor to be up to speed.

I have the Master running in my car, but it's not monitoring the cell voltages yet until I get the multi slaves built. It's counting SOC though.

The Master does not simulate as it's too complicated and uses lots of strange I/O you really need to build one to experiment with it. In fact I just tried it and it crashed the editor due to the I2c routines.

The editor is good for finding syntax errors etc. I wrote most of the code in windows notepad, only loading it into the editor to check it and then upload it to the chip!

Boelle send me your e-mail address and I will send you the latest Master. I can't upload it to my webspace due to on holiday and forgotten server password

[JonSpence]

The editor is good for finding syntax errors etc. I wrote most of the code in windows notepad, only loading it into the editor to check it and then upload it to the chip!

Not sure if it's any help, but you might like to try notepad++ as a editor. I find the colour coding very useful and it's ability to leap around to specific functions (works for C, not sure how well it works in other languages).
Anyway it's free, so costs you nothing to try it.

http://notepad-plus.sourceforge.net/uk/site.htm

[boelle]

pm with e-mail sent

the car i'm going to get when i have the money is a citroen saxo, the build in charger is controlled by a pulse width signal, would it be possible for the master to control that?

[retepsnikrep]

The Master can output a pwm signal on the charger control opto line. How exactly is it controlled? What freq etc, spec from manual etc. You can modify the software as you wish. Peter

[boelle]

i need to get that info from another guy that are trying to program the computer/charger for lifepo4 cells...

[retepsnikrep]

The charge profile for Lifepo4 cells is pretty simple.

Constant current for first part at whatever current cells can take or upto max current charger can deliver if less than max cell charge current.

Maintain this until any cell reaches cutoff voltage.

Then hold voltage for second part until current falls below about 500ma-1A

BMS must ensure charger output is conntrolled to prevent any cells going over V.

Some bypass balancing takes place during the constant V phase and they stay in balance very well.