The code of my final project for an Embedded Systems (Systemy Wbudowane) course at AGH - a simple oscilloscope for the Open1768 board. It captures waveforms using the board's ADC and displays them on a 3.2" LCD screen.
The oscilloscope has been tested and works reasonably well with periodic signals of frequencies ranging from around 1 Hz to a couple of kHz.
- Captures and visualizes signals from the in-built ADC
- Displays waveforms on a 3.2" LCD screen
- Adjustable voltage (
dv) and time (dt) scales - Edge-based trigger detection, with configurable trigger level
- UART output for logging
The project is structured into multiple modules:
- Buffer: Manages signal data storage
- LCDControl: Handles graphical rendering on the LCD
- Control: Manages user input (joystick, buttons) and stores the application config
- ADC: Configures and manages ADC sampling, along with the very important ADC interrupt handler
- Trigger: Implements edge-based signal triggering
- Main: Initializes components and runs the main loop
The program is based on interrupts, with the main thread responsible only for drawing the traces (when the do_draw flag is set). The ADC interrupt handler (executed every 20 us, after the ADC has performed a measurement) keeps track of every n-th (depending on the dt setting) measurement and checks it for the trigger condition. If the condition occurs, the procedure starts filling a buffer with each consecutive sample collected, and then sets the do_draw flag.
A more detailed description of the project can be found in the sw-oscilloscope.pdf file (in Polish).