How I program GPIOs in C | Embedded System Project Series #12

Рет қаралды 8,944

Күн бұрын

I program the I/O-pins on my robot (and development board) according to the pin assignment in my schematic. Writing to registers is cumbersome, so to make things easier, I implement a code abstraction in C that lets me configure and initialize all pins in a single place.
The git repository:
github.com/artfulbytes/nsumo_...
0:00 Recap
0:44 Introduction
1:57 Why start here?
3:18 Setup
4:00 Pin Mapping
5:40 How are IO pins configured?
7:25 Memory-mapped registers
8:56 Blinky example
9:42 Defining the interface (io.h)
10:15 Select register
11:32 Direction register
11:59 Resistor register (pullup/pulldown)
13:22 Input register
13:57 First commit
14:39 How to implement?
15:39 Bitwise operation (code trick!)
17:29 Array indexing (code trick!)
18:52 Implementation (io.c)
19:53 Testing the code
22:38 Second commit
22:55 Initialize all pins
28:27 Third commit
28:44 Last words
#embeddedsystems #gpio #cprogramming
⌨️ My development environment
www.artfulbytes.com/devenv
🌍 Links
GitHub - github.com/artfulbytes
Website - www.artfulbytes.com
👨‍💻 About me
Hi and welcome. I'm Niklas, an embedded systems engineer from Sweden. On this channel, I make practical videos about embedded systems or, in general terms, about building and programming hardware.

Пікірлер: 17

@palaaaurinkoon Жыл бұрын

Thank you for this wonderful series. Can't wait to see what's next.

@needywallaby2030 2 ай бұрын

i was searching for copper but found a gold this channel is best imo

@renanpils 4 ай бұрын

This series is awesome man! Very good content!

@redwoodenjoyer 11 ай бұрын

You are so, so smart and good at explaining this. Coming from Arduino and slowly leveling up my knowledge and realizing that even something as simple as direct bit banging was the TIP OF THE ICEBERG for all of firmware

@artfulbytes 11 ай бұрын

Thanks! haha yep, lots of details hiding underneath :)

@olivialinden8699 Жыл бұрын

👍

@user-sj9kh4pf7n Жыл бұрын

Only now I've realized: TI - Texas Instruments😁🤣

@artfulbytes Жыл бұрын

😁

@zDoubleE23 4 ай бұрын

Any good sources where the preprocessors like #ifndef, #end, etc are explained and exemplified with use cases?

@artfulbytes 4 ай бұрын

No resource to cover them all, I've just picked it up here and there. But as I mention somewhere in the series, avoid them when you can because they can lead to hard-to-debug issues down to road.

@3deesuk Жыл бұрын

in 16:55 min , what is pin_bit? i understand pin number and port number. what is different between io_pin_bit and io_pin_idx? (io & IO_PORT_MASK) >> IO_PORT_OFFSET this gives port 0 instead of port one for IO_10?

@artfulbytes Жыл бұрын

pin_bit is the bit value and pin idx is the position idx of that bit value. For example, for pin number 7, the bit value (pin_bit) is 0b10000000 (dec: 128), the 7th bit is set. Pin idx is 7, because it's the 7th bit position. For pin number 3, the bit value is 0b00001000 (dec: 8), and pin idx 3. Yes (io & IO_PORT_MASK) >> IO_PORT_OFFSET gives value 0 for IO_10. But in io_port_e enum, value 0 corresponds IO_PORT1 (there is no IO_PORT0). I did it like this because in TI calls the first port 1 (not 0) in the datasheet.

@pablocabellojordan2943 7 ай бұрын

Hi there, just found this channel, and this is exactly what I would love to do. I'm learning self-taught, but gets to hard for me. Can you please tell me something like a routemap so I can use to study?. (Something like: first you have to learn C, then electronics, then ...).

@artfulbytes 6 ай бұрын

Firstly, I would just focus on writing programs in C without any microcontroller, just programs running on your host machine, to get familiar with it. Once you feel somewhat comfortable you can pick up a simpler microcontroller, like an 8-bit one. Start small. Try to blink an LED with a GPIO, detect a button press with interrupt, hook up a sensor and write a driver to talk to it learning about uart/i2c/spi... You will have to do some simple circuits to connect things so you will learn some electronics as you go along. You don't need to be an expert in electronics if you purely want to focus on embedded software. Also I don't like the word "study", you don't learn embedded systems by reading a book, you learn by doing. Note, I'm not saying you shouldn't read, but that you should read what you need to know to do what you want to do. So not "How to learn C", instead more "How do I blink an LED with GPIO on the microcontroller I have in front of me"... Something like that :)