1. Test and Assembly Plan Results P09141 Satellite Thermal Heater Controller

2. Interface Board The final assembly of the interface board involved creating an active low-pass offset filter using resistors, capacitors, and an op amp on a breadboard. Three interface boards were built, one for the master and one for each of the two slaves.

3. Interface Board Testing Using a function generator set to a sine wave at the required frequency and an oscilloscope to monitor the output, the interface board was adjusted until the output had the correct DC level, frequency, and amplitude. Several changes were made during testing. Capacitance values and resistance values were adjusted. An op amp was added.

4. Enclosure The enclosure was designed using Pro/ENGINEER and analyzed using ANSYS Workbench. Several iterations of the design were created as customer defined specifications. The enclosure was then machined out of 6061 Aluminum Alloy and provided to the customer for testing.

5. GUI GUI was programmed in Labview. It sends and receives over serial and displays the temperature, telemetry, and other information. GUI can communicate with up to 256 slaves.

6. GUI Testing was done on the GUI as we went. Each part was tested separately and then built up to a working whole. Loopback testing was implemented by Scott before the DSPs were ready.

7. Communications (PC to DSP) This part was programmed in C using Code Composer. Communication is done over serial and took bytes from LabView and built a message to send to slaves. Also took message from slave and communicate back to LabView via serial.

8. Communications (PC to DSP) Used Hyperterminal as a proxy LabView interface to send and receive messages. Once that was tested, the GUI was substituted for Hyperterminal.

9. Communications (DSP to DSP) The communications between the master and slave DSPs was also coded in C using Code Composer. A 40 bit message was constructed, transmitted via the PWM and low-pass filter onto the power bus. It is then demodulated using the ADC and the Goertzel algorithm and converted back into a 40 bit message. A new message is then constructed and returned.

10. Communications (DSP to DSP) The function generator was used with the ADC to test and refine the functionality of the Goertzel algorithm. The PWM was attached through the low pass filter to an oscilloscope and analyzed to get the right frequency and amplitde. The PWM and ADC were connected and a message was sent and triggered on the oscilloscope until it was correct.