Microcontroller controlled altimeter

1. A microcontroller controlled altimeter comprising:

a microcontroller;

a digital altitude pressure sensor with a pressure indicating output coupled to the microprocessor; and

at least one Form A solid state relay coupled to the microcontroller,

wherein the microcontroller is configured to provide control signals to the at least one Form A solid state relay to:

provide an open circuit between normally open and common terminals of the at least one Form A solid state relay if the digital altitude pressure sensor output is less than, or equal to, a setpoint for the at least one Form A relay; and

provide continuity between the normally open and common terminals of the at least one Form A solid state relay if the digital altitude pressure sensor output is greater than the setpoint for the at least one Form A relay.

2. The microcontroller controlled altimeter of claim 1 , wherein the at least one Form A solid state relay comprises an isolating driver coupled to the control signals to the at least one Form A solid state relay, driving a pair of FETs connected back to back.

3. The microcontroller controlled altimeter of claim 1 , further comprising:

at least one Form C solid state relay coupled to the microcontroller,

wherein the microcontroller is configured to provide control signals to the at least one Form C solid state relay to:

provide an open circuit between normally open and common terminals of the at least one Form C solid state relay if the digital altitude pressure sensor output is less than, or equal to, a setpoint for the at least one Form C relay;

provide continuity between the normally open and common terminals of the at least one Form C solid state relay if the digital altitude pressure sensor output is greater than the setpoint for the at least one Form C relay;

provide continuity between normally closed and common terminals of the t least one Form C solid state relay if the digital altitude pressure sensor output is less than, or equal to, the setpoint for the at least one Form C relay; and

provide an open circuit between the normally closed and common terminals of the at least one Form C solid state relay if the digital altitude pressure sensor output is greater than the setpoint for the at least one Form C relay.

4. The microcontroller controlled altimeter of claim 3 , wherein the at least one Form C solid state relay comprises a pair of isolating drivers coupled to the control signals to the at least one Form C solid state relay, each driving a pair of FETs connected back to back, wherein the pairs of FETs are connected in series.

5. The microcontroller controlled altimeter of claim 3 , further comprising:

a hardware lockout circuit through which the control signals from the microcontroller to the at least one Form A solid state relay and from the microcontroller to the at least one Form C solid state relay are coupled; and

a breakwire conductor that when grounded, enables the hardware lockout circuit and disconnects the control signals from the microcontroller to the at least one Form A solid state relay and to the at least one Form C solid state relay.

6. The microcontroller controlled altimeter of claim 5 , further comprising a communications port, wherein the microcontroller is further configured to:

collect telemetry data comprising one or more of a telemetry packet number, a state of the breakwire conductor, the microcontroller control signals to each of the at least one Form A solid state relay and to the at least one Form C solid state relay, an output of each of the at least one Form A solid state relay and the at least one Form C solid state relay, the setpoints for the at least one Form A and the at least one Form C relays in feet, the setpoints for the at least one Form A and the at least one Form C relays converted to pressure, an output of the digital altitude pressure sensor; a current temperature, and a firmware version and checksum of the microcontroller; and

communicate the telemetry data through the telecommunications port.

7. The microcontroller controlled altimeter of claim 1 , further comprising a system programming port configured to load the at least one setpoint into a memory of the microcontroller.

8. The microcontroller controlled altimeter of claim 7 , wherein the system programming port is configured to load systems programs into the memory of the microcontroller.

9. A method of operating a microcontroller controlled altimeter comprising a microprocessor, a digital altitude pressure sensor with a pressure indicating output coupled to the microprocessor, and at least one Form A solid state relay coupled to the microprocessor, the method comprising:

operating the microcontroller to provide control signals to the at least one Form A solid state relay to:

provide an open circuit between normally open and common terminals of the at least one Form A solid state relay if the digital altitude pressure sensor output is less than, or equal to, a setpoint for the at least one Form A relay; and

provide continuity between the normally open and common terminals of the at least one Form A solid state relay if the digital altitude pressure sensor output is greater than the setpoint for the at least one Form A relay.

10. The method of operating a microcontroller controlled altimeter of claim 9 , comprising constructing the at least one Form A solid state relay using an isolating driver coupled to the control signals to the at least one Form A solid state relay, driving a pair of FETs connected back to back.

11. The method of operating a microcontroller controlled altimeter of claim 9 , wherein the microcontroller controlled altimeter further comprises at least one Form C solid state relay coupled to the microcontroller, the method further comprising:

operating the microcontroller to:

provide an open circuit between normally open and common terminals of the at least one Form C solid state relay if the digital altitude pressure sensor output is less than, or equal to, a setpoint for the at least one Form C relay;

provide continuity between the normally open and common terminals of the at least one Form C solid state relay if the digital altitude pressure sensor output is greater than the setpoint for the at least one Form C relay;

provide continuity between normally closed and common terminals of the t least one Form C solid state relay if the digital altitude pressure sensor output is less than, or equal to, the setpoint for the at least one Form C relay; and

provide an open circuit between the normally closed and common terminals of the at least one Form C solid state relay if the digital altitude pressure sensor output is greater than the setpoint for the at least one Form C relay.

12. The method of operating a microcontroller controlled altimeter of claim 11 , comprising constructing the at least one Form C solid state relay using a pair of isolating drivers coupled to the control signals to the at least one Form C solid state relay, each isolating driver driving a pair of FETs connected back to back, wherein the pairs of FETs are connected in series.

13. The method of operating a microcontroller controlled altimeter of claim 11 , comprising using a hardware lockout circuit to disconnect the control signals from the microcontroller to the at least one Form A solid state relay and to the at least one Form C solid state relay, when a breakwire conductor of the hardware lockout circuit is grounded.

14. The method of operating a microcontroller controlled altimeter of claim 13 , comprising:

collecting telemetry data comprising one or more of a telemetry packet number, a state of the breakwire conductor, the microcontroller control signals to each of the at least one Form A solid state relay and to the at least one Form C solid state relay, an output of each of the at least one Form A solid state relay and the at least one Form C solid state relay, the setpoints for the at least one Form A and the at least one Form C relays in feet, the setpoints for the at least one Form A and the at least one Form C relays converted to pressure, an output of the digital altitude pressure sensor; a current temperature, and a firmware version and checksum of the microcontroller; and

communicating the telemetry data through a telecommunications port of the microcontroller controlled altimeter.

15. The method of operating a microcontroller controlled altimeter of claim 9 , comprising loading the at least one setpoint into a memory of the microcontroller using a system programming port.

16. The method of operating a microcontroller controlled altimeter of claim 15 , comprising using the system programming port to load systems programs into the memory of the microcontroller.