1. Purdue Airbus Software Design Jigar Gandhi - John-Taylor Smith - Chandler Wall - Eric Zarowny

2. PWM – written and tested* • UART – written but not tested • Camera – outlined in pseudo code • SD Card – written but not tested • Battery Management – outlined in pseudo code • Ground Station – outlined in pseudo code Software Development Status

3. We need to spend as little time as possible in interrupts because we have so many. • We need as much of SRAM as possible for image buffering. • We need the transfer speed to the SD card to be as high as possible so we will not be using SPI. • We need a compression ratio that strikes a balance between image quality, time spent compressing and image size. Software Design Considerations

4. Arrangement

5. Interrupt Based • Our transmitter only has the four channels necessary for manual flight control. • The Autopilot board requires a fifth channel to control what flight mode is currently activated. • The PWM output of our microcontroller will emulate a RC transmitter and output specific pulse-widths. PWM

6. PWM Program Flow Chart

7. Interrupt Based • Autopilot/Microcontroller UART • Receive telemetry data from the Autopilot. • Transmit new GPS coordinates to the Autopilot. • Microcontroller/XBee UART • Receive a new flight mode from the ground station. • Receive new GPS coordinates from the ground station. • Transmit telemetry, battery, and image data to the ground station. UART

8. UART Program Flow Chart

9. VBLK indicates the period in which the camera will be outputting data • HBLK indicates that the camera has data ready to be captured Camera

10. Operates as a state machine. • After initialization, the card will enter an idle state. • When the image buffer on the microcontroller receives data from the camera, a data ready signal will be sent to the card. • The data will be sent to the card using 4-bit SD mode until the FIFO is empty, at which point the card will be sent a command telling it there is no more data. • The card will then return to the idle state. SD Card

11. Operates as a state machine. • To query the battery monitor from the idle state, a logic high must be pulsed for a specified duration on the bus. • Once a second pulse is returned from the battery monitor, a hexadecimal command can be sent to the monitor. • The command will execute, return the results asked for and then return to the idle state. Battery Monitor

12. The Ground Station will be run on an Intel Atom board. • It will overlay the telemetry and battery data onto the image data received from the microcontroller. Ground Station