Get a job working in embedded systems. Preferably in the right industry.
Like any programming job, but without formal experience you'll need more (and interesting) informal experience, ie side projects.
Start with something simple, like an STM32Discovery board. Blink the LEDs. Respond to the button.
Get a logic analyzer, like a Saleae ($400 for the Logic8) or Digilent Digital Discovery ($200, worse software IMO) or something similar. Get a bench power supply. Get an oscilloscope (Rigol DS1054Z is cheap ($400 or so) and hackable. Don't get a PC-based one, get one with a UI similar to what you'll use in professional work.) Get a couple of cheap USB-UART adapters, maybe a BusPirate, an ST-Link, and a hand full of STM32BluePill boards.
Get an SPI flash memory dev board, and write code to read/write that external flash. Use the STM32's built-in SPI peripheral. Use the logic analyzer to decode the signals & for debugging.
Get an I2C sensor dev board, and write code to read the sensor value. Use the STM32's built-in I2C peripheral.
Get FreeRTOS running on your Discovery board. Make tasks for your sensor reads, LED control, maybe log data to the SPI chip. Show that it's all hard real-time.
From there, maybe add more inputs & outputs. Making a 3D printer or CNC router from scratch would be impressive. Or an RC car, or some sort of robot, or a drone. Maybe go to a more capable SoC, like a BeagleBone Black board or Raspberry Pi. The product I work on (an eletronic logging device for the trucking industry) was initially prototyped using a BeagleBone Black. (This post is my own opinion, and should not be taken as official statements of my employer.)
Or go to a less capable chip, like a PIC16F18345 ($12 dev boards) and see what you can do with <=1024 bytes of RAM.
Definitely learn to build your code without using the vendor IDE. It'll save you a lot of pain. Makefiles (or CMake, or whatever build system you prefer) + writing linker scripts +
pointing your preferred IDE (or editor) at that is a much better way.
Espressif's ESP32 and ESP8266, Nordics NRF52 parts, and some others have built-in networking (BlE, WiFi, Cell, etc). Those can be good for all sorts of projects.
There's some industry bias against Arduino, it's seen as overly abstract and not something "real" programmers use. If you get an Arduino, it can be a great starting place, but also get an ICSP (In Circuit Serial Programmer) and learn to use the ATMEGA328p chip without the Arduino bootloader+libraries. It's a fine chip and a fine platform, but not necessarily great for resume building.
Basically look on Adafruit and Sparkfun and the like, figure out what sorts of sensors & outputs look interesting, and start making things to use them. The product lines I mentioned happen to be popular among hobbyists, which means less chance of getting stuck without community help available.
Like any programming job, but without formal experience you'll need more (and interesting) informal experience, ie side projects.
Start with something simple, like an STM32Discovery board. Blink the LEDs. Respond to the button.
Get a logic analyzer, like a Saleae ($400 for the Logic8) or Digilent Digital Discovery ($200, worse software IMO) or something similar. Get a bench power supply. Get an oscilloscope (Rigol DS1054Z is cheap ($400 or so) and hackable. Don't get a PC-based one, get one with a UI similar to what you'll use in professional work.) Get a couple of cheap USB-UART adapters, maybe a BusPirate, an ST-Link, and a hand full of STM32BluePill boards.
Get an SPI flash memory dev board, and write code to read/write that external flash. Use the STM32's built-in SPI peripheral. Use the logic analyzer to decode the signals & for debugging.
Get an I2C sensor dev board, and write code to read the sensor value. Use the STM32's built-in I2C peripheral.
Get FreeRTOS running on your Discovery board. Make tasks for your sensor reads, LED control, maybe log data to the SPI chip. Show that it's all hard real-time.
From there, maybe add more inputs & outputs. Making a 3D printer or CNC router from scratch would be impressive. Or an RC car, or some sort of robot, or a drone. Maybe go to a more capable SoC, like a BeagleBone Black board or Raspberry Pi. The product I work on (an eletronic logging device for the trucking industry) was initially prototyped using a BeagleBone Black. (This post is my own opinion, and should not be taken as official statements of my employer.)
Or go to a less capable chip, like a PIC16F18345 ($12 dev boards) and see what you can do with <=1024 bytes of RAM.
Definitely learn to build your code without using the vendor IDE. It'll save you a lot of pain. Makefiles (or CMake, or whatever build system you prefer) + writing linker scripts + pointing your preferred IDE (or editor) at that is a much better way.
Espressif's ESP32 and ESP8266, Nordics NRF52 parts, and some others have built-in networking (BlE, WiFi, Cell, etc). Those can be good for all sorts of projects.
There's some industry bias against Arduino, it's seen as overly abstract and not something "real" programmers use. If you get an Arduino, it can be a great starting place, but also get an ICSP (In Circuit Serial Programmer) and learn to use the ATMEGA328p chip without the Arduino bootloader+libraries. It's a fine chip and a fine platform, but not necessarily great for resume building.
Basically look on Adafruit and Sparkfun and the like, figure out what sorts of sensors & outputs look interesting, and start making things to use them. The product lines I mentioned happen to be popular among hobbyists, which means less chance of getting stuck without community help available.