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TI Stellaris plus AT Modem project to connect to Exosite


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This project demonstrates how to use a Stellaris Development Kit to send and receive data to/from the cloud via Exosite's Cloud Data Platform. The communication with the cloud is accomplished over HTTP with the Janus-RC GSM864Q GPRS modem. The project sends the AT command over a UART to the Janus modem. The project functionality writes a 'Ping' value to the cloud and reads a value 'interval' from the cloud. Cloud information is shown on the on-board LCD screen. For some development kits with enough screen size, an option to read a public temperature data source is also available to display on the screen.
The source code in this folder is a project called "Stellaris ATDT Cloud" which has been verified with Code Composer Studio 4 and IAR for the following TI Stellaris Development Kits:

  • EK-LM3S6965 (with addition of RS232 Transceiver)
  • EK-LM3S1968 (with addition of RS232 Transceiver)
  • RDK-IDM-L35

Note: This code can be used with any of the Stellaris Development kits that have a UART accessible. Some modification may be required depending on the UART used and the display/LCD available. Also, some kits have RS232 signal levels on UARTs (like the RDK-IDM-L35) and others are only TTL. For TTL UART signals, an RS232 transceiver will need to be connected to properly interface with the cellular modem which accepts an RS232 serial connection. For more information about this project visit Exosite Github Profile.

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For me, doesn't make much sense to buy a $150 Janus AT based modem w/closed source drivers that has a 1kb packet send size limitation and is very slow, plus whatever the cost of your dev board is. Your sample code shows a basic "1 time back and forth" network connection, so it's not fair to imply that this gives full "cloud communication" - which it doesn't. Doing it like u posted will give one user space program a slow, expensive rs232 internet connection. Many other negative side effect like not being able to poll for sig strength (or any other data) while transferring, receive size limitations, and the list goes on.


For all that trouble I'd just buy a $40 rasberry pi/beaglebone type board w/a $40 USB 3g modem, use open source drivers (usb_modeswitch, sakis3g, wvdial, etc) and now I have an embedded project w/3g kernel drivers to give internet to the send/recv socket API's, just like a desktop w/full networking freedom. Doing it this way is cheaper, faster and more reliable.

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