This document provides an overview of training materials for an embedded starter kit focused on bare metal programming of LEDs and buttons. The goals are to create firmware to control LEDs and read button presses, learn about the hardware operation of LEDs and buttons, and learn GPIO input/output and interrupt basics. It introduces GPIO configuration as digital I/O with pull-up/down resistors or analog, covers GPIO pin functionality, and discusses using interrupts to address the delay issues of polling button states in a main loop. The practice section has the learner set up a project to control an LED based on a button press via polling initially, then refactors to use interrupts to eliminate delays.

1. GlobalLogic
Embedded Starter
Kit
LEDs and Buttons
Training 02
Bare Metal
Trainings

2. Contents
▪ Assignments and Goals
▪ Theory
▪ Practice
▪ Individual task
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3. Assignments and Goals
• Create firmware that works with LEDs and
buttons
• Learn LED and button HW background
(how it’s working)
• Learn GPIO I/O basics
• Learn GPIO_EXTI interrupts
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4. LEDs schematics
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5. Buttons schematics
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6. General-purpose I/Os (GPIO)
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7. General-purpose I/Os (GPIO)
GPIO pin can be configured as
• Input/Output pin with/without
pull up/down resistors (digital)
• ADC/DAC pin (analog)
• Alternative function
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8. General-purpose I/Os (GPIO)
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9. General-purpose I/Os (GPIO)
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10. General-purpose I/Os (GPIO)
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11. General-purpose I/Os (GPIO)
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12. General-purpose I/Os (GPIO)
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13. General-purpose I/Os (GPIO)
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14. General-purpose I/Os (GPIO)
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15. Practice
• Create new Keil Project
(see Pract_01 for details)
• Set HW settings (with CubeMX)
– PA15 – GPIO_Input (SW2)
– PD15 – GPIO_Output (LED6 Blue)
• Complete main while loop with code
provided
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16. Practice
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17. Practice
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18. Add source code
• Modify source code with
snippets from following file
• Compile
• Flash
• Press “SWT2” button to test
FW
• What main disadvantage of
this solution?
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19. Main loop timeline
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Pooling

20. Add interrupts
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21. Enable interrupts
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22. Modify source code
• Modify source code with
snippets from following file
• Compile
• Flash
• Press “SWT2” button to test
FW
• Issue disappeared?
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23. Main loop + IRQ timeline
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Interrupts

24. Individual task
• LED blink frequency change using switches
• Blinking LED number change using switches
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