Battery Vehicle Society

V10 good spot

Not sure about CellS

CellS is used to store the unloaded cell voltage from a known acquisition with the loads off.

The sequence goes

1) Turn off loads.
2) Measure cell voltages and store CellV in CellS. Report V to master
3) Turn on loads according to CellS

I'll look at it. Suggest try is as is first to get it working.

If we have thickish short wires to the cells we may be able to revert to the older software where we did not have to turn off the loads to take the cell V

VData was/is the low byte of the CellV word variable. But if you define VData as a separate byte variable, unrelated to CellV, then you can use the statement VData = CellV - DLow. CellV stays unchanged so you can still use it later instead of CellS. CellS becomes redundant, so we can get rid of it, freeing up a whole 2 bytes of memory.

EDIT: Actually it only saves 1 byte, I forgot that VData needs a byte.

retepsnikrep wrote:If we have thickish short wires to the cells we may be able to revert to the older software where we did not have to turn off the loads to take the cell V

We could have both options in the software. Add another command like this
By adding a new command we keep compatibility with the existing master software. The new functionality will require changes in the master software, but the new slave software will still work with the older master software, you just don’t get the new features. It also means you have more flexibilty in wiring. You are not required to use thicker, shorter wires if you don't want to by using the command 2, 1, 3 combination. Note, I haven't yet upgraded my pbp to the latest version so I can't test these changes. Also, this example uses my idea of ditching the CellS variable, but it would be simple to change this.

retepsnikrep wrote:Looks nice but for auto assembly in china can the machines cope with parts at an angle I've only ever seen pcb's with stuff at 90 degrees or aligned vertically or horizontally?

I just saw this video on pick and place process, note the battery holders are at a 45 degree angle.

http://www.eevblog.com/2012/04/04/eevblog-264-pcb-pick-place-assembly/

EDIT: pcbs have been shipped! I'm away next week, hopefully they will be waiting for me when I get back.

Got the pcbs today.




I've been away over the Easter holidays and haven't had time to order the components yet. Hopefully will be able to order the bits later this week.

Looks good www.pcbcart?

These came from itead.

I've ordered enough parts for all 10 pcbs. I'll build a few of them to start with and some more when we know it works.

I found a mistake in the BOM, the Farnell part no for the opto was incorrect, I've fixed it below.

I'll have to start on the 12F683 Master now!!

Good effort Greg

I had a go at building a couple of boards. I still need to work on getting the correct amount of solder paste on the pads and also the right amount of heat, U301 got a bit too much!

It's not good enough to go in something at the moment but I could try and program it for starters. Peter do you have a hex file I could try? I haven't updated my pbp yet.