Orbcomm Protocol Docs: Checking to see if these can be posted, have to check if they're under NDA or not.
Modem works well with Digi Jumpstart Kite provided 5/8ths wave whip antenna on a 2x3ft metal plate (cover of an old server) on the roof of the building. Gets data through on about 50% of the sat passes.
Digi Jumpstart kit has been invaluable, and is frankly absolutely necessary for starting out with this modem system. It provides easy software to operate the modem, a PCB that's got nice USB and serial ports, a beefy power adapter, a great magmount whip antenna, and long coax cables.
Host port baud rates: 300, 600, 1200, 2400, 4800, and 9600
Default default host port baud rate: 4800
Rebooting: Toggle PWR EN, wait for DA to pulse high before sending serial data to sat modem.
Note: If the Digi m10 is powered off, all existing messages in its transmit and receive queues are lost.
Each packet ends with a fletcher checksum. The example C code in the Orbcomm Serial Specification works verbatim with the Arduino IDE.
There are very many packet types, only a few are needed for simple message passing. Use the debug interface to set settings instead of trying to do it with packets, to save development time.
These settings are stored in non-volatile memory. It is more complicated than it's worth on a microchip to try to set these programmatically. Thankfully, the Debug port allows setting them using a computer serial terminal interactively from the keyboard. It even has menus. See below for details.
SC Parameters and our desired value:
Note: Bracketed numbers indicate a footnote exists at the bottom, not some actual value. Scroll to the bottom of the google doc embeded to see important commentary.
Provisioning is activating a new modem through Orbcomm. These settings are for the trans-atlantic flights. See ORBCOMM MESSAGING SYSTEM DESCRIPTION REV F Doc for details
The message packets sent between the Digi m10 Satellite Modem and the Satellite are optimized at 107 bytes of user data. This allows for a single packet to be sent to the Satellite with a single acknowledgement back. After that, the next optimized size is 228 bytes of user data, and then in 111 byte increments.
For messages originating from balloon, 1 = Normal priority, only non-delivery to ORBCOMM Gateway acknowledged - acknowledgement generated by SC based on lack of communication with satellite or ORBCOMM Message Switch (OMS)
Connect to debug using ASCII comm terminal such as HyperTerminal, level shifted to 3.3v, 115200 baud, 8N1. Backspace is allowed. All data is entered in DECIMAL ASCII numbers, followed by an <enter> key. Don't try to enter hex numbers, and make sure you convert the “Parameter Number” to decimal. The Orbcomm Serial Spec lists them in HEX.
There are over 100 commands/menu options available in the Debug Port interface. Type 1<enter> for a list of commands. Here's the command printout from our Digi m10.
Enter the following command sequence, using ASCII numerals:
You will see recognizable english responses to these, and it will factory reset. Host port will be set to 4800 8N1.
One of the most important is the “Set Parameter” command. This allows you to set the value of any parameter.