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AssigneeTexas Instruments Incorporated
InventorsMark E. Miller, Timothy L. Anderson, Ronald E. Garnett
Estimating the term…
In a receiver circuit module (22) having a microcontroller (U1), an output line (FILTER_LED) connectable to a source circuit module (20) is also used as an input. A switch (SW2) disposed in the source circuit module is closed to change the wave form which is read by the microcontroller as an input signal to drive a 5V signal to the gate of a solid state switch (Q1) turning it on to thereby energize an output device in the source circuit module via the same output line (FILTER_LED). By means of the dual function of the output line the control can notify a user of an HVAC system, for example, of system problems with a blinking light and/or an audible alarm as well as serving to notify the user at a remote location that selected maintenance is due, such as a need to change filters without additional control lines. The source circuit module can be mounted near the thermostat of the HVAC system or on the central heating and cooling unit.
A method for two way communication between first and second circuit modules, the first circuit module having a microcontroller with inputs and outputs comprising the steps of taking a microcontroller controllable switch and serially connecting it to an output line extending between an output connection point and logic ground, controlling the state of energization of the switch by the microcontroller, connecting the output connection point to an input of the microcontroller through a voltage divider, the second circuit module having an output device, providing a full wave rectified power source and connecting the rectified power to the output device and to an output connection point, reading the wave form at the said input of the microcontroller on a continuing basis and selectively changing the wave form on the output line in the second circuit module to thereby use the output line as an input signal to the microcontroller, the microcontroller, in response to reading a change in the wave form actuating the microcontroller controllable switch to allow current to flow in the output line through the output device to thereby use the output line as an output.
Apparatus having two way communication between two circuit modules comprising
Dependencies are inferred from the claim text.