Old BMS Software Thread

[joshp1990]

Just re-programmed the chip, and the problem still persists....

here is a link to a longer video of what is going on

http://www.youtube.com/user/danmachen#p ... Lhpg2OPCM8

just for a test we put in an old version of the PICAXE chip into the board, and we didnt come across any of the scrolling character problems that are shown here.

Also, i was wondering, if the SV2000 was damaged, how would we be able to test for that to know for sure? and If the PICAXE runs without this sort of problem does that rule out a hardware failure?

Many Thanks

[steiner]

Peter,

Thanks... that was the issue. I had "FailSafeV" set to 340. It must have been right on the edge such that a slightly longer sense wire would make it trigger. I reduced it down to 320 and everything is working correctly now.

Rick

[retepsnikrep]

Josh/Dan the bms is clearly operating in the background but the video is screwed.

Very odd I think I have a spare video chip.

That new video does not cover the power up sequence as I requested

Turn everything off, start filming, then turn the master on.

[isaac_alaska1]

almost there! (i think)
running PBP3, and have figured out how to use MPASM as the assembler (turns out it's the default assembler in PBP3 and so isn't an issue)

The next thing i have to do is modify the code a little bit to fit my battery system, i'm using LIPO batteries so the voltages are a little bit different. The code i'm working with for the slaves is version SLAVE_V09_070211_MPASM. the code that needs to be changed on the slave is:

RefVADC con 63200 'Fixed Ref Voltage Calibration LM385 1.235v * 1023 * 100 / 2 = 63200
DLow con 175 'Cell correction value 175 (1.75V) subtracted from CellVoltage
DHigh con 430 'Cell correction value 430 (4.30V) (If Cell V>430 or <175 then error)
CutInVD con 365 'Balancing load/bypass default cut in Voltage (Must match value set in Master)
FailLowDef con 335 'Default Fail Safe Minimum Load voltage Cut off (3.35V)
FailHighDef con 385 'Default Fail Safe Maximum Load voltage Cut in (3.85V)

i'm not entirely positive what all of these refer to. the maximum voltage for my batteries is 4.2 volts per cell, but being charged to 4.1 volts after balancing is what i'm going for.

This is what i have so far:
RefVADC con 63200 'This stays the same
DLow con 175 'This stays the same
DHigh con 430 'This stays the same
CutInVD con 365 'I think this one should be changed to 410
FailLowDef con 335 'I don't know what to set this one to (an explanation would be great)
FailHighDef con 385 'I think this one should be set to 420

does this look close to what i'm trying to do?

thanks for the help!

-Isaac

[retepsnikrep]

FailLowDef con 335 'I don't know what to set this one to (an explanation would be great)

All looks OK to me.

The FailLowDef should be changed to just above the abs minimum cell voltage. So that if master fails the slave can turn off it's own load when cell voltage goes below the value you specify.

[retepsnikrep]

Here is some updated software for use with Pic Basic Pro 3 and above with new configs.

They all compile correctly on my system but are untested in the field.

Good Luck

Peter

[isaac_alaska1]

BMS is working perfectly on the bench. i have it set up to read from a six cell lipo battery, driving a little TFT car lcd screen. haven't set up the speed sensor or current sensor inputs yet, but that's the next step with it. I used the previous PBP3 codes peter just uploaded, and changed the voltage settings around for my LIPO batteries. In the video it jumped back to the home screen a few times when i was trying to read the voltage levels, i'm not sure why. it might be something to do with my buttons being set up on a breadboard right now and not having soldered connections, or maybe i'm not waiting long enough after entering the "cell voltages" screen before hitting the down button. but, a very minor issue none the less!

not the best pictures, as i took them with my phone, but here it is on the bench.











video to come shortly, as soon as i figure out my youtube password.

a huge thanks to Peter Perkins, first of all for starting this project and making it open source and available to everyone, and second for answering all of my noob questions and walking me through most of PBP.

also thanks to everyone else who's helped me out, and everyone involved on here

thanks guys!

[retepsnikrep]

Well done Issac nice pics.

Re buttons I can't see a 1M pull up resistor on your breadboard

[isaac_alaska1]

hmm...the schematic i have doesn't show a 1M resistor anywhere. this is what i followed:



do i need to change something?

sorry for the huge picture... i'll stick a 1M resistor between pin1 and pin6 of J1

[retepsnikrep]

That is an old one put a (1M to 200k) between +5v and switch signal line.

See pics and schematic for a very neat version.

Switch2.jpg (46.71 KiB) Viewed 18458 times

SWITCH.jpg (23.76 KiB) Viewed 18458 times