CE865 Coursework

Autumn Term 2025

The coursework in CE865 is worth 30% of total module mark. It consists of two components:

•    Lab Exercises: 30% of the coursework

•   Coding project: 70% of the coursework

1.  Lab Exercises

You need to read the document “CE865 Lab Notes for STM32F412” in the course Moodle site. In the lab notes, there are a few lab exercises at the end of each lab session. You need to complete and submit your code for four of them. They are listed below:

1.1      Exercise 6.2: UART

The PC serial port connection console is used as a stopwatch driven by  the STM32F412 board. You can combine the USART2 and TIM6 codes together to work out a stopwatch. The timer interrupt is configured as 10ms. The USART2 should send the current milliseconds and seconds to the PC console to show a time in the format of “00:00” to “59:99”. And then go back to “00:00”.

1.2      Exercise 7.2: PWM

Initially, you need to configure one of PWM channel with a PWM period of 500Hz and the duty cycle of 50%. Then you need to use the buttons in the shield to control the PWM signal. You can have four buttons for starting PWM, increasing duty cycle, decreasing duty cycle, and stopping PWM.

1.3      Exercise 8.2: I2C

You need to develop a code which can continuously read the ALS measurement and display it in LCD. Your code also needs to make the PWM duty cycle of TIM2_CH1 proportional to the ALS measurement so that the light intensity of onboard LED (LD9) can be changed according to ambient light intensity.

1.4      Exercise 9.2: RTOS

You need to develop a code using FreeRTOS. You can use task 1 to read ambient light intensity from the ALS sensor (see lab 8), use task 2 to read accelerations from the MC3479 sensor, and use task 3 to display the readings from both sensors.

2. Lab Exercise Marking Scheme

You need to demonstrate your work in the lab session to the module supervisor or GLA. You don’t need to submit the source files or report. But you will be asked to explain the code during demonstration. The demonstration will be on week 9 and 10 in the scheduled lab sessions.

Marks will be awarded as follows according to the quality of source code, the quality of solution, and the ability to explain the code.

•    UART exercise worth 25% of Lab Exercise marks

•    PWM exercise worth 25% of Lab Exercise marks

•    I2C exercise worth 25% of Lab Exercise marks

•    RTOS exercise worth 25% of Lab Exercise marks

If you don’t demonstrate your work for one of lab exercises, the mark for that lab exercise will be zero.

3.  Coding Project

3.1      The Board

The development board used for this coding project is STM32F412G DISCOVERY kit and the shield. There is a list of laboratory sessions you need to attend before attempting this coding project. These laboratory sessions help you to use the development boards and the associated software. Extra time may be needed for some laboratory sessions. In many cases example source code is provided for the laboratory tasks. You should familiarise yourself with them before you start any programming.

You will need to read the “CE865 Lab Notes” and lab board manuals first. They can be found on the CE865 course webpage on Moodle.

3.2     The Task

The objective of this coding project is to implement a reaction test timer by using the development board.  The reaction timer displays the time it takes for the user to react to an LED being illuminated. It displays the time in seconds to an accuracy of one thousandth of a second in the format from 0.000 to 9.999.

a)  On start-up or after a reaction test has completed, LED  1 should flash with the rate of 1s to indicate Button 1 is to be pressed to start the next reaction test.

b)  When Button 1 is pressed, the display is zeroed; all the LEDs are turned RED and begin to count down (turn off) at the rate of 0.5s. The countdown should be from right to left.

c)  When the last LED turns off a random LED is lit (turned GREEN) indicating the button that should be pressed to stop the count on the display. At the same time the display begins counting, showing the elapsed time.

d)  When the indicated button is pressed the display stops counting and the elapsed time stays constantly. LED 1 should flash with the rate of 1s. The timer is ready for the next reaction test (returns to step a).

e)  If the user presses any button other than the button indicated by the LED the count should continue. If the user fails to react, the count stops at 9.999 seconds and LED 1 should flash with the rate of 1s. The timer is ready for the next reaction test (returns to step a).

f)  If the user presses one or more buttons before the countdown of LEDs finishes, the countdown is suspended until all the buttons are released.

There is a video under Coursework on Moodle you can watch to have a better understanding of what you need to achieve in this task.

3.3     The Method

The reaction timer should use the timer resource on the MCU chip to ensure an accurate time period and the LCD library to turn the LCD display into a digital clock display device. The lab sessions have introduced these concepts so would be good to revisit them if needed.

You will need to create or use functions to read the state of the Buttons and set the colour of the LEDs.

You are encouraged to program your code using a finite state machine, where each state should be clearly defined and the transition from one state to another should be clearly defined. This is a more organised way to implement all the required functions.

4. Coding Project Marking Scheme

The task of coding project is to implement a reaction test timer using the development board in the lab. You will be assessed on the source code you submit, the demonstration, and the report. Before the deadline, you are asked to demonstrate your code to the modular supervisor or GLA in the lab.  When you are ready for demonstration, just let us know.

Marks will be awarded as follows:

4.1     Well Commented and Structured Code (10%)

All the functions in the code should be well commented, describing their purposes and operations. Specially you need to provide detailed comments on the variables and functions you declared, on how to achieve 1ms accuracy for timer display, on how to achieve 1s LED countdown, on the random number you generated, on how the main loop is structured, etc. All the code produced should be well structured and appropriate layout and control statements should be used.

4.2     Code demonstration (20%)

You need to demonstrate your code to the modular supervisor or GLA in the lab session. You may be asked to explain the code you used. Failing to explain your code will lose marks.

4.3     Display Functionality (25%)

The marks for the Display Functionality logics are made up as follows:

•    Use of timer interrupts and accuracy of Reaction Time count

•    Display of elapsed time with the rate of 1ms

•    Reaction Time count stops at 9.999

•    Restart from 0.000

4.4     Button/LED Interface (25%)

The marks for the Button/LED Interface logics are made up as follows:

•    Efficient implementation of button functions to avoid button detection delays

•    Efficient implementation of LED functions with the countdown rate of 0.5s

•    Flashing LED start indicator with the rate of 1s

•    Random button detection stops countdown

•    Return to the start point after one loop

4.5     Implementation Quality (10%)

This will evaluate your ways to implement the functionality. A higher mark will be awarded for novel implementations, such as finite state machine, random number generation, less use of delay function, novel use of timers, etc.

4.6     Discuss potential use of RTOS for the code project (10%)

You need to provide some ideas on how to use FreeRTOS to implement the reaction test timer. You don’t need to develop code. You just need to explain how many tasks you would like to create and why. You also need to explain what the SysTick timer interval is and why. Do you need to set the task priority and why?

Do you need to use task communication and/or coordination mechanism and why?

5. Submission

The deadline for submitting the code and report is on FASER. You should submit:

•   One file containing the only source file (main.c) in plain text format, which can be compiled and downloaded to the board for testing, for the coding project. If your code is implemented in multiple files, please submit them together.

•   One word or pdf file (max 5 pages) to describe how the required functions are implemented in your code for the coding project. You need to briefly explain how your code is compiled and downloaded in STM32CubeIDE if you use multiple source files, header files, or other libraries.

No extensions of the deadlines will be given; if, for any reason, you do not submit your work there will be no record of the  submission time and you will automatically get a zero mark.

I strongly encourage you to submit your work on time, even if it is incomplete. Some credit is always better than none.

This assignment is to be done individually, i.e., whatever you hand in must be your own individual work. Any software or any other materials that you use in this assignment, whether previously published or not, must be referred to and properly acknowledged.