Embedded Programming: Emulating a Mars Rover

This project was done as a part of EE2024: Programming for Computer Interfaces at National University of Singapore (NUS). Project owners: Naman Sharma, Pan Jieming. The aim of the project was to emulate a robotic mission sent to mars using a FPGA (LCP1769 in this case, with a basebard consisting of multiple sensors). This mars rover is named HOPE, short for Habitability Observer ad Precursory Explorer. The mars rover is supposed to collect various sensor readings and send these back over to the base station using wireless communication.

Detailed Description and Specifications for HOPE

1. The three sensors on board HOPE are: accelerometer, light intensity sensor and temperature sensor.

   a. Accelerometer: Used as an inclinometer for HOPE, to prevent it from getting into an unrecoverable position while moving around the terrain of Mars

   b. Light sensor: Dust storms on Mars create lightning, and the presence of these dust storms require the robot to go into a SURVIVAL mode.

   c. Temperature sensor: The temperature of te sstems needs to be maintained within an appropriate range, and therefore temperature measurement is crucial.

2. HOPE has two modes of operation: EXPLORER and SURVIVAL. The explorer goes through an initialization phase when it starts up, where the segment_display counts up from 0-6, A-F and then starts in the EXPLORER mode.

3. In the EXPLORER mode, all three sensors are sampled at intervals of SAMPLING_TIME and the readings are shown on the graphics display. hese values are also to HOME using a UART wireless interface.

4. HOPE automatically enters into a SURVIVAL mode as son as the light sensor detects LIGHTNING_THRESHOLD being crossed at least three times within a time frame of the past LIGHTNING_TIME_WINDOW. When HOPE goes into SURVIVAL mode, it performs the following actions:

   a. INDICATOR_SURVIVAL LED will turn on, and the INDICATOR_EXPLORER LED will switch off.

   b. The graphics display will stop showing all sensor values and all measurements from the sensors will stop.

   c. HOPE send a message to HOME alerting it that survival mode has been activated, and no more senosr values will be sent back to the base station.

   d. Provided that the luminance level from the light sensor is below LIGHTNING_MONITORING, another LED from the INDICATOR_ARRAY will turn off for every TIME_UNIT that has passed.

   e. Any time that the luminance level from the light sensor is above LIGHTNING_MONITORING, INDICATOR_ARRAY will turn on all the LEDs and restart the countdown sequence described above.

   f. If all LEDs of INDICATOR_ARRAY are off, HOPE automatically enters the EXPLORER mode, sendng a message to HOME stating that the SURVIVAL mode has ended and it will begin sending sensor data.

The SURVIVAL mode of HOPE has been programmed using interrupts, to allow for immediate switching between the modes. The parallels between the scenario and the actual setup are shown in the graphical overview of the system below:

Code Structure Description

1. Report.pdf : Contains detailed description of code, including flowcharts of decision steps.
2. Code/src/Assignment2.c : Main file for the code. Includes the code for intializing the various peripherials using I2C, SSP, GPIO etc. Defines the use of various interrupt handlers such as TIMER0_IRQHandler (for updating LED precisely at 1s) and EINT3_IRQHandler (for switching from EXPLORER mode to SURVIVAL mode). The main() function handles reading the different sensors and transmission of the data to the base station.