Master Board Version 3

Threads relating to the BMS system begun by Peter Perkins

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Re: Master Board Version 3

Postby GregsGarage » Thu Oct 21, 2010 8:39 pm

The nice thing about the current display is it is cheap, universal and will never be obsolete. You will always be able to buy video monitors and the small lcd ones from China are dirt cheap. The SV2000 serial to video chip will be replaced in V3 with a Tellymate which is cheaper, open source code and gives better resolution. The problem with using surplus hardware like old palms and windows mobile pdas is you keep chasing a moving target as old equipment becomes unavailable. Not a problem for a one off project, but if someone is trying to duplicate it, there could be a lot of re-engineering if the particular palm, ipaq, pda is no longer available. The existing hardware could be made to work as a "headless" BMS with a relatively small amount of work on the code. The hard stuff has already been done. :shock:

My personal view is that in my own car I don't want a car-puter, the existing display is fine. It would be nice to have data logging to say a SD card. I know there are some Arduino projects that do this. I haven't investigated it for PicBasic, might have a look and see if someone has done that already. I would be happy to have a data log to a SD card and then analyze it later. Even better would be to make the data "loop", a bit like a black box. You just leave the card in unless you notice a problem, then you can take it out and analyze it at home.
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Re: Master Board Version 3

Postby Fufunka » Thu Oct 21, 2010 9:18 pm

I can more or less subscribe to that, however, in the previous post I was just little bit surprised to hear that the planned master bms board V3 perhaps might not have enough capacity (due to lcd output work among other things) to perform such crucial operations as logging alarm states (and onload buffer from those high/low batt/regen/.. values) into the data output, which could be considered as priority for a core of any bms system.

My take on these frontend addons, is make the basics as widely standard as possible, that's why that proposed serial rs232-2-ethernet, where it can be read down the road by any device capable of digesting webpages, it's like 99.9% devices these days. Also such serial output can be read on Java enabled devices, again this is global standard, "everybody" has got it in their PC or mobile phone like since early 2000s. These standalone gfx displays for the new display chip in master V3 is obviously a very nice unit, especially the AMOLED ones, but for the same price, you can have bridged router in the garage and watch the progress of charging, reviewing past recorded data or GET THE ALARM MESSAGE ON TIME, easily from your home couch as the phev/ev is parked dozens meters away or across the globe, plus have that Ipaq on dashboard too.

About PDAs it's not about the specific-ever-aging devices at all. In particular, that Ipaq 4700 has been used on so many various projects (from robots to real airplanes) before because of the well balanced package it's a little computer: large touch with good sun readability, speed, communication (able to clone the serial data output from master bms over local network/internet), store data on memcard etc. It's very nice, but I'm not in this Ipaq/winmobile centric at all, but what ticked me is the application as seen for that Honda SUV has been done, it's working, so if the author won't mind sharing, it can been hooked to this bms as well.

I'm not proposing to make the project headless at this point of time (V3), just trying to highlight many easy picked addon opportunities for it, currently laying on the table.

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Re: Master Board Version 3

Postby retepsnikrep » Fri Oct 22, 2010 4:24 am

The master should have enough hardware/software capacity as it will now be using the x2 memory chip 16F1939 and we are going for a 40 pin device. At present we have two serial I/O on the board. One using the hardware usart which I am intending to use for Gregs controller interface. The other software serial I/O will probably be good for upto 57600 baud as the cpu can run at 32mhz using the internal oscilator. We have six I/O lines free I'll post the schematic shortly so ideas for the other I/O greatfully recd.
Regards Peter

Two MK1 Honda Insight's. One running 20ah A123 Lithium pack. One 8ah BetterBattery Nimh pack.
One HCH1 Civic Hybrid running 60ah A123 Lithium pack.

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Re: Master Board Version 3

Postby Fufunka » Fri Oct 22, 2010 10:56 am

Thanks for the clarification, yes seems as plenty of power. To put the separate question of Ipaq PDAs at rest for the moment, I contacted the author on the following address, lets wait a bit what eventually turns out on that front. Ipaq PDA EV dashboard link contact page: http://www.emobilis.lt/

In the meantime, I'll try focus on the basic raw data outputs later stored as .csv logs (excel/oo base), possible batch/script/macro automation post-corrections, simple webpages etc. Peter as next opportunity allows, would you pls. upload some actual raw data logs and your excel sheet/macros, so we can play with "real" data?

You discussed it earlier that eventually, the move from provisional DAQ to manually in hyperterminal, or any serial communication (rs232-2-ethernet) and datalogging made upstream (device not specific) will be the way to go:
viewtopic.php?f=53&t=2060&start=350

Sooner or later it will be better to offload all this talk to a separate "BMS Master & remote monitoring tools & frontends" thread. Just a mental note here for the particular segment of web frontends (no Java MIDP or SCADA yet): seems the best approach would be always start the public/private domain site for a particular ev/phev project with a blank web page, text menu/hyperlinks only>

[RSS Channel]
[Web Lite - Mobile Device Browser Basic (<15kb)]
[Web - Mobile Device Advanced (<50kb)]
[Web - Home PC, WAN, Carputer, Highend Mobile Communicator (!Warning: No Limit Data Plan Needed)

--
[RSS Channel]
// only few core values circling on the ticker are presented (Time, SOC, 2x High/Low #Cell states, Temps, Alarms, ..) - this could be placed on everything for instance on screensavers for various standalone devices, e.g. my IP telephone has got such screensaver showing RSS ticker, it could be anything from PC webrowser addon to kitchen appliance and toys, PalmOrb (new role for old hw), lcd/led ticker signs, cheapo keychain picframe/photoframe (openwrt), wireless pictureframe-yawcam, other crazy ideas..
[Web Lite - Mobile Device Browser Basic]
// basic datadump similar to RSS ticker, no active graphics
[Web - Mobile Device Advanced]
// active yet tiny graphics (graphs), still not much demanding app, ala jQuery plugin sparklines
[Web - Home PC, Carputer, Highend Communicator]
// full features (menu-data transformations on the fly), loaded graphics
we can start it with something simple like LiveGraph http://www.brucelawton.org/Monitor.html

--
So, you can choose what kind of device/tool you are momentarily about to look at, becuse that changes around the day, and you are not stucked if something goes wrong..

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Re: Master Board Version 3

Postby GregsGarage » Sat Oct 23, 2010 9:52 am

retepsnikrep wrote:The master should have enough hardware/software capacity as it will now be using the x2 memory chip 16F1939 and we are going for a 40 pin device. At present we have two serial I/O on the board. One using the hardware usart which I am intending to use for Gregs controller interface. The other software serial I/O will probably be good for upto 57600 baud as the cpu can run at 32mhz using the internal oscilator. We have six I/O lines free I'll post the schematic shortly so ideas for the other I/O greatfully recd.


Peter, I will need to use a software serial I/O for my controller interface. I have found that the simplest way to connect a pic to a RS232 serial port is to use a 22k resistor between the TX of the RS232 and RX of the pic. Then by inverting the serial comms on the pic this direct connection works with no additional hardware. Problem is, it is not possible to invert the hardware usart. From the pbp hersout2 entry
Since the serial transmission is done in hardware, it is not possible to set the levels to an inverted state to eliminate an RS-232 driver.


Regarding the spare pins, 6 is what is needed to do logging to a sd card. PBP has a library SDFS3 already setup for this. The bad news is it uses pbpl so requires a 18F pic. Maybe it would be better to do it separately like this. http://www.jianpingusa.com/jpmodule.asp I understand the product was developed with pbp.
Greg Fordyce

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Re: Master Board Version 3

Postby retepsnikrep » Sat Oct 23, 2010 5:13 pm

We can use software serial I/O which should be fine.

The sd card thing is nice but feature creep again. People who want to can use the external device with a serial connection so that's fine.

The excel files/macros/software are in the software thread a few posts back. I don't have any data as I have never bothered to collect any apart from my test setup for a few minutes or so.

Basically we can have the spare I/O comming out to a connector which people can use as they wish. As mentioned I'm v busy so don't expect to do anything much with BMS for a while.

I suggest Greg get yours running with V2.
Regards Peter

Two MK1 Honda Insight's. One running 20ah A123 Lithium pack. One 8ah BetterBattery Nimh pack.
One HCH1 Civic Hybrid running 60ah A123 Lithium pack.

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Re: Master Board Version 3

Postby GregsGarage » Sat Oct 23, 2010 9:47 pm

Agreed, lets just provide a serial I/O that can be used for whatever data logging/capturing that people want to use. I am in no hurry for V3 and would rather spend some time with V2 and get it working perfectly. Then I/we will really know what we need for V3. I will put the data logging thingy on my long list of things to do. :shock:
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Re: Master Board Version 3

Postby retepsnikrep » Mon Oct 25, 2010 5:13 am

Here is the schematic for V3, ignore duplicate component labels. This is unchecked. And we have 6 I/O lines left.

It has hardware and software serial I/O.

www.solarvan.co.uk/bms/MasterV3_16F1939.jpg

I especially interested in any obvious errors, ideas for the other 6 I/O, and any other input filtering ideas to prevent interference getting in on the inputs. You will note the master bus in now has some simple additional filtering. Do we need that on any of the others?

Peter
Regards Peter

Two MK1 Honda Insight's. One running 20ah A123 Lithium pack. One 8ah BetterBattery Nimh pack.
One HCH1 Civic Hybrid running 60ah A123 Lithium pack.

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Re: Master Board Version 3

Postby GregsGarage » Mon Oct 25, 2010 11:53 am

I've had a quick look at the latest schematic. A couple of comments.

How about adding current limit resistors to J11 pin1 and J12 pin 1. I know the picaxe didn't use this, but it seems to be best practice for other examples I have seen.

J11 as drawn won't work for RS232 level serial I/O. The reason is to use that circuit requires the pic to invert the serial signal. This can only be done with software and is not available on the pic's hardware usart port. One RS232 port should be enough, so I suggest we just use this as ttl level serial I/O with a current limit resistor on each pin.

For the unused pins, maybe bring them out to a "generic" circuit with enough flexibility to allow use as input or output. Maybe even have a "breadboard" area next to them as well.
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Re: Master Board Version 3

Postby dillond666 » Tue Jan 11, 2011 7:44 pm

Peter,

I was looking at the in4148 diodes on the master bus input and am not clear on how they work.
Are they like flywheel diodes to deal with the inductance of the bus when the opto transistors open? (total guess!)
Please put me out of my misery and explain :)

I'm using fibre optics when I do a proper job of my rather Heath Robinson BMS effort.
http://uk.farnell.com/avago-technologie ... /dp/327750

Derek


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