Atmel AVR
WiFi Radio

Lost At Sea

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APRS Tracker
Generator Natural Gas Conversion
Allstar Node 43710
Allstar USB FOB

Local Radar

Allstar Node 43710

Here are the details of the Allstar node I built using a Raspberry Pi 2, BF-888S, and CM108 USB sound card.

The switch shown below on the left turns off all power when down. Normal operation is when it is in the middle posistion. If it is toggled to the up position and left for two seconds, it forces disconnect from all active nodes. But when left up for six seconds the Pi will activate shutdown. The Power LED is connected to the activity pin of the sound fob, and its blink patern signifies activity; slow flash is standby and fast flash means it is playing audio. If a shutdown is commanded, it's safe to turn off power about five seconds after the LED turns off. The Receive and Transmit LEDs are driven from the BF-888S and show the state of the radio.

The back exposes the power in, BF-888S adjustment knobs (modified for a screwdriver), antenna connection, and Ethernet/USB on the Raspberry Pi.

To mount the radio, I drilled a hole as close to the final heatsink pad as I felt comfortable getting.

I also used a saw to cut the stands for the belt clip off, and sanded them smooth.

I used 3M heatsink tape between the back of the radio and the heatsink. Next time, I would like use a solid block of aluminum.

Even with the fins, the heatsink conducts the heat to the bottom plate of the enclosure nicely. It gets quite warm after an hour of full duty-cycle transmit.

Since there's really nothing special about how I mounted the rest of the boards inside, here are just a few pictures...

More information about how I wired the USB FOB to the Radio can be found here.