Out of the box, the $89 beaglebone device may be readily adapted to use a USB-based Cellular data access device, such as the Sierra Wireless 250U device that works on the Ting.com network for a low $9 per month month-to-month plan providing for 100 Megabytes of remote telemetry. These instructions tell you exactly how this is done.
The above photo shows a minimalist use of the single USB port to support a Sierra Wireless 250U device that connects the beaglebone to the internet. In this simple configuration, no additional USB hub is needed and the cellular modem is powered from the beagle bone. Using the BASH scripts below, you can cause this arrangement to dial up the Internet and give you an IP address from Sprint's network. With that IP address, you can SSH or get web services from the beaglebone with no other connectivity.
This particular Sierra Wireless 250U device shown was purchased for $75 directly from ting.com. However, we have also purchased an identical device from other suppliers and it works just the same.
Since this is a CDMA network, there is no SIM card. To register the device, you must read the ESN off of the device and associate it with your ting.com account on their web site. Within seconds of registration on their web site, the device starts working. One device worked right away. However, I had to contact Ting.com by phone on the other device. In either case, the activation requires only a small registration fee by credit card. I recently noticed that ting.com no longer sells this model device directly, even though they are supported on the ting.com network. (Ting.com is an MVNO operator on the Sprint network).
As a side note, the ting.com technical support is radically good. They are so very helpful and very good at what they do. I have no idea how they make money at this, but thats not my problem at the moment.
While hooking the beagle bone up to the Internet in this way, this particular arrangement only puts your beaglebone on the Internet using a cellular device instead of using a wire-line ethernet RJ45 internet or a wi-fi device. You should know that in the event you happen to ALSO have an internet connection via the ethernet RJ45 LAN port, your beaglebone may not actually use the cellular internet connection until you hit the part in a script below that changes the default route.
It is far more interesting to use a USB hub and an additional device or two also powered by a USB hub. We show a OneTouch Ultra2 blood glucose meter on one of the other available USB ports of this low cost 4-port hub. We used a Digitus Slim Spider USB Hub. A standard USB-to-serial cable provided by the OneTouch manufacturer is shown.
With this arrangement the assignment of devices to /dev/ttyUSBxxx ports is dynamically made and decoding this mapping is a key first step to using any of these devices in other scripts.
The serial protocol used to get data out of the blood glucose meter is really another story on its own. The details for doing that, and the requisite python code for doing that is here: https://github.com/bewest/insulaudit
The USB assignments are decoded by this script usb_discover.sh
/etc/ppp/peers/gprs-connect-chat – this script works for Sprint
I'd be delighted to have any updates/comments/corrections.
Earle West firstname.lastname@example.org