Simp BMS

[tom91]

Can reduce the deadzone.

This is what it is, so 500mA.

Code: Select all

if (currentact > 500 || currentact < -500 )
    {
      ampsecond = ampsecond + ((currentact * (millis() - lasttime) / 1000) / 1000);
      lasttime = millis();
    }

[joromy]

Have not had time to check into the programming bit.
Have ordered a teensy and will do some program testing.
Don't want to program the Simp BMS, and mess it up.

I'am using arduino IDE, is that good enough, or should I go for something else?

[tom91]

You can always just flash the original .HEX from the github back in using the Teensyloader.

All software is written via Arduino IDE.

[joromy]

Anyone know hot to get a analog SOC gauge to work?

SOC.JPG (11.92 KiB) Viewed 7026 times

I'm connecting it to OUT8 (conn4 pin15) and to pin 4 on the SOC gauge.
When the SOC meter is unconnected, it show 50% (middle)

This is how it looks on paper:

The top of gauge is feed 12V (pin 11) and the bottom (pin 4) was connected to the old BMS.
I think the old output where open collector (LOW)

When connected to Simp BMS the PWM signal is getting lower (in volt) when pulse width increase.
Does this mean it is to weak to drive it?

[tom91]

No the Simp BMS gauge output is also a grounding signal, so higher PWM duty is a lower resulting voltage.

If you try lets say a low duty and a really high does the gauge move?

[joromy]

Yes it moves from under 0 to 50%, when I run the SOC gauge test.

If I connect it to 12V it goes over 100%, and under 0 if I connect to GND.

[tom91]

Can you measure the resistances on that pin to ground and 12V.

Also can you use a power supply and vary the voltage to see if the gauges follows it?

[joromy]

I put in the original BMS, and did some scope saves with 0% OSC and 100% SOC:

This is how it looks with simp BMS:

The SOC gauge will not go over 50% even with high duty...
Have I killed the output, or is this how it should look?

[tom91]

This does not look right, can you check it with just a simple 10K to 12V instead of the gauge?

I can run some tests myself, but I would need some information on what the load is of the gauge.

[joromy]

The last scope save is with 10K pullup, and no gauge connected.
Will do some test on the bench and check the PWM from microcontroller.

Will the Simp BMS outputs work with only 12V power and no cell comm?

[tom91]

Not really, I would have to modify some coding for testing then.
The only is a basic output debugger that just hard switches the outputs.

When the BMS is in error state it wont allow the closing of the contactors, thus the operation of the outputs beside the gauge one.

[joromy]

Don't bother with that, there is more important coding that needs to be done

[tom91]

This is what a Gauge output looks like powering an LED with 550 ohm resistor.

So I would say something is wrong with your board, possibly damaged a mosfet.

[Johaljaswant]

Can some one explain in detail how to download Editor on Nextion Display for SimpBMS.

Thanks

[tom91]

Can some one explain in detail how to download Editor on Nextion Display for SimpBMS.

Thanks

https://nextion.tech/editor_guide/

Download files from here and open with nextion editor https://github.com/tomdebree/SimpDisplay

[Johaljaswant]

I connect Nextion display connect to computer with USB-TTL .but it did not show on computer ( nextion display )where I can download files to it. Either I am have not that much skill or something is wrong.
Please guide.

Thanks

[tom91]

It should work just fine, I just followed the instructions from Nextion. Please check your USB to TTL shows on com ports.

[Johaljaswant]

Hello Tom91
In Nextion editor I try to download simpdisplay.
It say target device does not match selected device
NX3224T024_011 (set model)
NX3224K024_011 (device model)
Please let me know how I can load programme on this display.
Thanks

[tom91]

Please learn how to use Nextion editor. The error is really simple.

[Johaljaswant]

I tried hard.
Please let me know how I can change device from NX322T024_11 to NX322K024_11.
Thanks

[Johaljaswant]

Done
Thanks

[CanadaLT28]

Tom, you were working on SimpBMS being able to control 2 Volt packs. Did you manage to get it done in purchaseable product?

Mike

[tom91]

Just got the parts in to rig up some testing.

It will be in two steps; A V2.3 board with a Teensy 4.0 instead of a Teensy 3.2 with a small extra board. Should be ready end of this year/beginning next year.

Then later once I am happy a V3 board just for the Teensy 4.0. Scheduled end of Q1 2020 I would say.

[joromy]

So I would say something is wrong with your board, possibly damaged a mosfet.

Ref: PWM out to analog SOC gauge.

Will try to change the mosfet, what is part number?

[tom91]

I would say please check the control signal first with the mosfet removed.

Mosfet Part number: IRF9956TRPBF