Considering open source Cycle Analyst/APM

scphantm

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May 8, 2011
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Im thinking about doing a project. My ebike is running a Crystalyte controller and APM at 48v. So far its been great, all the problems I have had with it in over a year and a half have been of the "you know better than that" variety so ive been very happy.

but like many of you, i like to tinker. I have an arduino laying here doing nothing and it came to me. why not do an open source version of the Cycle Analyst/APM boxes for this thing. i figure start with a data logger feature with a GPS and Wireless board to log whats going on in say 1/10th second intervals, and setup the wireless where as soon as it senses the connection, it uploads the data to your home server where you can write reports on it till your blue in the face.

Once the data logger part is done, then work on a real time display. use something like a 5 or 7 inch LCD or LED display and build a real dashboard, something like you would see in the electronic dashboards of high end cars. gauges for voltage, amps, display watts, speed, etc. whatever our heart desires.

Im pretty sure i will have a pretty tough time with this on the crystalyte controller as it seems noone has the specs for the data feeds that go into the APM, but maybe we can do this with an infinity controller, something everyone has hacked to death and knows inside and out. who knows, this may end up becoming an advanced arduino powered, open source controller project.

anyone interested in helping? i have zero interest in doing this alone.
 
Ive been thinking about this also. it would be usefull for power limniting power on a rc motor ebike and also traction loss prevention or traction controll. I have 2 bikes with a ca v3 on both and highly recomend them. however i think this is a valuable thread for anyone that wants to play with a programable integrated circut like the Arduino. I am thinking about getting a leo stick for $30 and seeing what i can do with an rc motor. I used to be a programer, and still dable from time to time, I have played with a PIC to make my car start and warm up remotely using the boot/trunk release on my alarm. i got as far as activating relays and sensing frequency but didnt conect it with opto isolators to the ignition coil, i had to make a binary servo thing that had a relay that switched polarity of a gear head motor and limit switches to "rev" the motor '85 v8 . anyway...

what hardware do you have Arduino wise?

as for displays these are avaliable:
product_15405.jpg

check freetronics, they have all sorts of Arduino compatible hardware.

I dont have allot of time really but i have prety much just finished my last project so i could start playing with this and make an Escooter.

EDIT:
also i have been considering a direct conection from the arduino to the fets so its like a controller and amp/cav3 in 1. i dont think that would be the hardest part of the project if it was done.
making the sofware compensate for its delay in sensing and activating the timing could be done logically as it goes or preset. also an accelerometer would be cool to get real actual efficiency values as it happens and even predictive over heating protection.. so many things. so much potential coding....

ps
http://endless-sphere.com/forums/viewtopic.php?f=30&t=38337&hilit=Arduino
 
GREAT LINKS!! i figured this subject has been brought up before. When i have some time im going to look at those other projects and see what i come up with. Im thinking an arduino as the central core. Im also thinking building my own controller will end up being fun. Imagine this, a bad ass controller with an arduino at its core that you can add shields to. you want constant 12 volt out of your controller, add the shield. then modify the code to add the power usage to your data logging. we could do all kinds of stuff.

i have a lot of reading to do. i will see what i come up with.
 
Hi,

noticed this thread yesterday. I've been building something which is very similar to what you're talking about, although not quite the same (linky). I'm using an arduino, 4x20 LCD display and other bits and pieces. All the code (and there's quite a bit!) will be released as open source but I'm holding off for the moment until the project is in a working status - very close but not quite there yet!

Here are some teaser pics:
outside-small.jpg
inside-small.jpg
 
I'm very intrested in this

about to start a arduino powered battery to battery pwm charger (to charge main pack from low C rate range extender packs)

also very interested in a arduino powered bms system
(http://endless-sphere.com/forums/viewtopic.php?f=14&t=49196)

I've got a CA3 (not fitted yet)... but it makes sense to go with one unit to do everything, and jut one display

once someone has one arduino system setup (gps, logging, bms, charger, throttle control), it should be easy for everyone else to integrate the code/hardware into there systems...

I'm still pretty new to ebikes... but I'm seriously surprised this hasn't been done already
 
Hi everyone,

I have made an e-bike computer using arduino. I am still working on it but I am close to the final result.

[youtube]z5xAHb5inZk[/youtube]

I have rode my e-bike to work for the first time after the winter the last two days and everything seems to work fine, I just need a minor code correction because the instant amps and Watts are changing too fast for my eye to see the value.

8)
 
Hi everyone,

Is anybody making progress on their open source CA/APM?

I just re-wired the connection from the main board to the screen today, it looks much nicer and tidy.

Before:

IMAG0134.jpg

After:

IMAG0191.jpg


I found some interesting boxes for the screen: http://www.digikey.ca/scripts/DKSearch/dksus.dll?Detail&itemSeq=129793820&uq=635038729806789732


At the moment I am powering the device using an external battery.

I accidentally found this voltage regulator on ebay http://www.ti.com/lit/ds/symlink/tl783.pdf
I ordered a couple and I will try to power the whole thing directly from the battery pack. This will make things a bit tidier (less wires..no need for external battery)
 
Some of the jumpiness can be smoothed with rolling averages, also if your doing oversampling to get 12, 14 or even 16 bit ADC resolution you can work the noise out in code.

Glad it seems to be working so well!

-Mike
 
Thanks guys!

I added some delay, so now the display shows the values every 0.3 seconds and it's more readable.
I also added a switch so I can turn on/off the whole "computer" when my bike is parked at work.

I did a quick test to self-power the whole device but it did not work, I will have to think of something, will do more test when I have time.


8)
 
"about to start a arduino powered battery to battery pwm charger (to charge main pack from low C rate range extender packs)"

why not just wire all the batteries together in parallel instead of keeping one separate to recharge the other when it drains down. seems like a big waste of energy to not take the charge directly from the pack. C rate has nothing to do with it. you can connect hi C and lo C in parallel.
 
dnmun said:
"about to start a arduino powered battery to battery pwm charger (to charge main pack from low C rate range extender packs)"

why not just wire all the batteries together in parallel instead of keeping one separate to recharge the other when it drains down. seems like a big waste of energy to not take the charge directly from the pack. C rate has nothing to do with it. you can connect hi C and lo C in parallel.

I agree. I Just finished my hybrid battery a month ago, it works well so far. It's all made from recycled batteries: http://jacklithium.wordpress.com/2013/03/29/hybrid-battery/
 
Could be his pack to recharge the other is a different voltage. But yeah, if same, just parallel them.

To some extent, you can even parallel different chemistries if the pack voltages are similar.
 
spuzzete said:
At the moment I am powering the device using an external battery.

I use an LM2576HVT to take power directly from my 36v battery. Note it is really *really* Important to use the high voltage version (HVT postfix). The standard non-HV version can take just above 40V and my 36V is over 40v when charged. See if you can guess how I know it's a bad idea ? :oops:
(yes, I did blow up my arduino, screen and lots of other bits :cry: )

I suspect that this HV part will also work with a 48V battery, but I've not tried this.

YMMV


sal_park
 
That sux you fryed your arduino!
I told my GF I wan get s bmx and put s motor on it. She cracked the shits but I think I'll get away with it so in the next week or so I'll order / buy a bmx, rc motor and esc , battery, arduino and LCD, shunt (50amp) and .. that's it I think, maby a saddle/handle bar bag.
 
spuzzete said:
sal_park said:
I use an LM2576HVT to take power directly from my 36v battery.

sal_park

Unfortunately it will not work for me because both my bikes run at higher voltages (54v and 72v).
I burnt a few atmega chips and a screen too during my tests :(

An option: LM5009, up to 95V in, up to 150mA out.
 
Thanks for the suggestions guys!

@ pendragon8000

I tested some laptop power supply and AC to DC power supply and most of them work as DC/DC converters. Problem is they are too big, I have little room on the bike, I would prefer something more compact and integrated in the pcb. Great idea though!
 
So what does the cycle analyst use? It can take 150v.
Some net book psu are quite small.
But yeah I know what your saying Spuz, I wana make a unit with the Leo stick and LCD shield and try keep it all very compact then use a 12v plug pack in the battery bag/box.
 
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