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Missions

The current primary communications payload contains the main HAM radio, TinyTrak TNC (modem), GPS, and DTMF board.

The GPS signal is converted from a serial (digital) signal to an analog tone via the TinyTrak TNC (similar to an old fashioned modem). The analog signal is then sent via the radio to our chase vehicle(s) which have another TNC to decode the packet.

The radio can also receive DTMF (audio dial tones) from the chase vehicle(s). We have two different DTMF boards we fly. One is single relay board. When triggered, by the correct numeric code the DTMF board closes a relay which activates a cut down circuit to separate the balloon from the rest of the payloads (to either terminate a mission early or to cut loose the remants of the burst balloon). The second DTMF board we use has 8 relays, each triggered by a differnt numeric code. The system is currently configured to allow 4 cut down circuits (for dropping payload and/or cutting the balloon free) and 4 standard switches to be activated. The switches are used to send commands to other payloads (which simply watch for a high or low voltage).