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peterantypas / maiana

MAIANA™ is the first Open Source AIS transponder. It proudly raises an extra long middle finger to the marine electronics industry, government overregulation and everything else that gets in the way of innovation in this space.
GNU General Public License v3.0
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Add hardware based mechanism to prevent runaway transmission #77

Closed peterantypas closed 3 years ago

peterantypas commented 3 years ago

Currently, if anything happens during transmission that causes firmware to stop executing or jump to the ROM bootloader, the most likely outcome is that the transceiver IC will remain in direct TX mode, clocking a constant bit value (probably 0), while transmitting indefinitely.

There needs to be a hardware based mechanism to shut down both RF ICs during reset. Perhaps pullups on their SDN pins?

peterantypas commented 3 years ago

RF MOSFET bias will fall to 0V, powering off the PA.