A transmitter to plug into many projects with a DB-9F connector

This Transmitter was originally in a different project, but was removed when that project was re-purposed. The shape derives from that.

Subsequently it was pressed into service with the Charge Control part of the Solar Charger to monitor the charging current from the solar array. The Controller and the Logging Terminal of the Weather Station were modified slightly to rrecord its transmisions.

This was so useful that additional protection circuits, a battery, and an enclosure were aded so that it could be used with any project with a compatible RS-232 signal just by plugging it in. The records are automatically stored in a file whose filename corresponds with the key code at the bginning of the data.

Currently, the Solar Charger, the Serial ADC, and the Serial Voltmeter work with it.