GSM/GPS bike communication system

[Fyod]

Hi guys,
I'm currectly working on a Cycle Analyst communication system. I would like some input on what you think about about a device like this. We have three Stealth-like ebikes ranging 3-7kW output, all sporting CAnalysts. The main goal is to connect the bikes to the internet due to possible theft, the ability to rent bikes and to have data logs.
Module features:
The module size is 35x17x10mm (approx. 0.7x1.4x0.5in) and weighs around 20 grams, fits in most handlebars
- 5-40V input
- 1S LiIon or LiPo battery input, charged from input 1 (though not neccessary on ebikes)
- 96Mhz ARM Cortex processor
- 256kB flash, 64kB RAM
- Quadband, class 12 GPRS/GSM module @ 85kbps (up/down), TCP/UDP/HTTP/FTP
- standard NanoSIM slot
- GPS/Glonass module, 2.5m accuracy, 0.1m/s velocity accuracy
- two U.fl connectors for external GSM/GPS antennas (can be placed in other parts of the bike far from the module)
- 1Mbps CAN transceiver enabling full CAN-BUS capability (other applications)
- a movement sensor wakes the rest of the system or alarms the owner (not an accellerometer - maybe on future versions)

So far, the module is easily reading from the CA Tx and sending the acquired data to an SQL server, along with GPS data.
What we would like to do is keep the code open-source for a communities and to enable users to use the features they want and/or program their own. The module is Arduino IDE friendly, so there are tons of libraries available for LEDs, sound, other features.
We would also like to keep the PHP script open to users who optionally want to install a server or already have a host.
There are many unused pins on the module that will enable tinkerers to add whatever other peripherals they'd like, ie. temp sensors, sound alarms, LED indicators, fingerprint readers, RFID, etc. With some simple wiring you could for example block any bike throttle until the module is called from a certain number. Text messages can be used to control pin inputs/outputs, query location, ...
I have not tried sending anything to the CA Rx, but this can also be done. Possibly program settings remotely?

Would this module be of interest to this community? Have we missed anything important or is there something you'd like to see on a module like this?
All ideas are welcome!

Cheers!
- Paul

 

[amberwolf]

- 5-40V input

I think you might want to make that significantly higher, so it could be run from / charged by the bike's traction pack on the more typical "48V" and higher packs (which tend to start at 58-60V+ at full charge, and may have charger input voltages higher than that which it's input would have to tolerate).

I have not tried sending anything to the CA Rx, but this can also be done. Possibly program settings remotely?

If the CA had the option (don't think it does from the Rx input), would be nice to have it autothrottle the bike down to no motor output, or even actively brake the wheels if it's setup for that.

Probably would have to be done via inline throttle and brake connectors that "intercept" the actual controls and alter them before they reach the controller.

Would have to think on what else would be nice to have.

There are a number of threads you might look into for features, generally about bike locks, bike theft, antitheft / location /tracking devices, stolen bikes, etc., as possible search terms.

 

[Samd]

Interesting. Subscribed.

 

[Fyod]

- 5-40V input

I think you might want to make that significantly higher, so it could be run from / charged by the bike's traction pack on the more typical "48V" and higher packs (which tend to start at 58-60V+ at full charge, and may have charger input voltages higher than that which it's input would have to tolerate).

I have not tried sending anything to the CA Rx, but this can also be done. Possibly program settings remotely?

If the CA had the option (don't think it does from the Rx input), would be nice to have it autothrottle the bike down to no motor output, or even actively brake the wheels if it's setup for that.

Probably would have to be done via inline throttle and brake connectors that "intercept" the actual controls and alter them before they reach the controller.

Would have to think on what else would be nice to have.

There are a number of threads you might look into for features, generally about bike locks, bike theft, antitheft / location /tracking devices, stolen bikes, etc., as possible search terms.

Thanks for your input.
I would love to have higher voltage input, but due to the size constraint, we're lucky Linear make a converter so small to allow 40Vin. 72Vin for example would require about 10 more components and we just don't have the space. But I don't think it should be too much of a hassle to connect to one of the batteries, in our case one of the 7S packs, worst case scenario one could have a dedicated 2S 3000mAh pack for example.
Also, efficiency goes downhill at those voltages, usually less than 80%, whereas ours is in the 95% region.
I'll search and read up on the topics you mentioned.

 

[amberwolf]

You might look into the way the Cycle Analyst itself regulates voltage using a pass transistor. I don't know the details of how it works, but it has about 100VDC input, all the way down to something like 10-12VDC, I think.

If you have a CA there you could probably reverse-engineer that pretty quickly.


As an aside, I see from your terminology that you're assuming the use of RC LiPo--most ebikes do not use that. Most use packs that don't have access to anything other than the main pair of output terminals.

For DIY ebikes, which is a pretty small percentage of ebikes (seems large here on ES but isn't in the world at large), I don't know the exact proportion of RC LiPo usage, but I expect that it is also not used to power the majority of them.

I've used it myself, but when on the bike it only had main pair of terminals accessible, had to be removed from bike to open the casing to get to anything else.


Efficiency at higher input voltages probably does go down...but if you're tapping off the traction pack's main outputs, the amount of power is probably negligible vs the pack's size and the motor's use.


Battery voltage and power source on a non-ebike could be anything; whatever works on that bike's physical construction.

But there is already a battery on an ebike, big enough to use for this, and there's not much reason to not leverage that.

It's just that many of those batteries are higher fully charged voltages (or during charge) than what your present design can handle. :/

 

[Fyod]

Good points. I'll certainly look into possible options.

 

[Fyod]