Battery Vehicle Society

next step is to reconfigure the "interlocks" pin as an output to drive a digital pot in parallel with the throttle pot, so we can linearly taper the throttle back to zero throttle as the cells drop voltage.

This is for PBP3, Master Boards V2.00 fitted with the AT24C512B Eeprom or compatible.

It adds a few new features.

1) Audible alarm toggle, turns off the alarm buzzer if you want. (Sub Menu 1) This resets each time you start the BMS. Default is on. The alarm screen still appears, it just means you can ignore it and drive without the buzzer annoying you if you want.

2) Max Temp, MaxPackV, MinPackV now display the trigger value in the Alarm screen.

Before it was "Pack > Max Temp" now it is "Pack > 47C" or whatever your constant is.

Max Pack Temp constant is set at 47C in this version.

I'm off to France in July in the car and I don't want the buzzer going off for two weeks and be unable to charge it!!!

Also, does anyone know of decent software (hopefully free) for drawing schematics? Trying to keep on top of any changes we make and it would also be useful for other circuits our team is using for our electric car. Thanks

danmachen wrote:Also, does anyone know of decent software (hopefully free) for drawing schematics?

Eagle is widely used in the 'open source' community

http://www.cadsoftusa.com/download-eagle/freeware/?language=en

Kicad is a popular open source program that doesn't suffer from the restrictions that the free version of eagle does. That's what I am using now.

i have a professional version of eagle, if anyone needs it

Isaac, how are the Xbees coming along? Have you tried using these yet. You'll probably need a MAX232 as well if you want to connect it to the PC for data logging.

I haven't had a chance to mess with them yet, sadly. i've been busy with another competition and finishing school, and now i'm up in greenland with the machine. i'll probably start working with those as soon as next semester starts, as i have a bunch of other modifications i want to do to the machine as well.

i just dropped the machine off at summit station, and i'm back in kangerlussuaq with no way to get to the machine myself. it's been there for 3 days now, and they've put 7.5 miles on the machine since i left. the temp during the day is about -20F and drops to around -36F at night.

the mechanic sent me this picture this morning and i was hoping someone might have an explanation. i've never seen it do anything quite like this before.

he didn't mention that any alarms were going off, or that the screen was doing anything else out of the ordinary (like flashing a fault code) so i'm thinking that maybe the number of cells was somehow reset to zero. i sent him instructions on how to reset the number of cells, as well as asked for more information about exactly what is being displayed and what the four LED's are indicating.

i'm sending him two new PICs, one of them is a copy of what is already in the machine and the second one is the older pic (16F886) with the other code on it.

any other ideas of what might cause this?

My guess would be you have no communications to the slaves due to Vol 0.0, hiV of 1.75 and loV of 4.30. These are the values you get at the start of the cell reading loop, no data means they don't get changed. Try sending code 7 to the slaves, this should cause them to flash their load leds. Also check all your slave connections.