arrow-firmware

Arrow

Arrow is a TNC smashed together with a BLE/Bluetooth, Wi-Fi, and 2M band radio. The 2M band radio is capable of voice, AFSK, FSK, MSK, and GFSK, and is automatically retunable across the 2M band. The current functionality is listed below:

• K.I.S.S. Style TNC
• Bluetooth Connectivity for TNC connection (SPP Profile)
• AX.25 support with P-Persistance CSMA
• Frequency Flexibiltity using the Hardware configuration byte in the K.I.S.S protocol.
• Built-in battery 3Ah w/ battery charger via micro USB connector

Frequency Selection

The hardware configuration byte of the K.I.S.S. protocol is used to select from a predefined table of frequencies. The K.I.S.S. protocol limits the configuraiton byte to...well...only a byte so a table is required. Currently, only 16 frequencies are defined to allow the 4 remaining bytes to be used for future capablities.

The table consists of mustly channels on the 2M experimential band 145.5MHz - 145.8MHz w/ 25kHz channel spacing.

| Index | Frequency | Comment(s) | |-------|-----------|------------| | 0 | 144.390 | APRS - NA | | 1 | 145.5125 | | | 2 | 145.5375 | | | 3 | 145.5625 | | | ...| ... | | | 15| 145.8625 | |

Demo

You can view a quick terrible demo of Arrow being used with Linux's build into TCP/IP over AX.25 support here:

In the view, I preview using the kiss-attach utility to attach to Arrow over a Bluetooth SPP connection, and ping another Arrow over AX.25.

Arrow can also be used out of the box with APRSDroid, etc via the Bluetooth connection.