63 article(s) tagged “Embedded Systems”. ← All Posts
Writing the LCD task of a Raspberry Pi proximity alarm in C: driving the BCM2837's I2C controller (BSC1) through /dev/mem, sending PCF8574 nibbles, waking up the HD44780 in 4-bit mode, and showing the live distance on an LCD1602 without flicker.
Read More →Wiring an LCD1602 with a PCF8574 I2C backpack to a Raspberry Pi 3 B+ with just four wires, keeping the I2C bus safe at 3.3 V, and testing it from the console with i2cdetect and i2cset before writing any code.
Read More →Writing the buzzer task of a Raspberry Pi proximity alarm in C: driving GPIO18's hardware PWM through /dev/mem, setting up the clock manager, mapping distance to volume and beep rate, and a 10 ms phase-counter tick for a parking-sensor sound.
Read More →Writing the distance task of a Raspberry Pi proximity alarm in C: mapping the BCM2837 GPIO registers at 0x3F200000 through /dev/mem, pulsing the HC-SR04 trigger, timing the echo to the microsecond with timeouts, and writing distanceCm into the shared frame.
Read More →Wiring a 5 V HC-SR04 ultrasonic sensor to a Raspberry Pi on GPIO23 and GPIO24: why the Echo pin needs a 1 kÎĐ / 2 kÎĐ voltage divider, how distance = time / 58 works, and measuring a real distance with a multimeter, pinctrl and gpiomon before writing any code.
Read More →Wiring a KSSG1203 passive buzzer to a Raspberry Pi GPIO18 pin through a 2N3904 NPN low-side switch: why a GPIO pin can't drive a buzzer, the 1 kÎĐ base resistor math, passive vs active buzzers, and testing it all with pinctrl and a multimeter before writing any code.
Read More →Adding a hardware alive task to a Raspberry Pi proximity alarm in embedded C: a pthread that blinks the ACT LED through /sys with fopen, takes and gives back the kernel trigger, and proves a frozen program with SIGSTOP.
Read More →Writing the first pthread of a Raspberry Pi proximity alarm in embedded C: a software alive task, one shared data frame protected by a mutex, drift-free timing with clock_nanosleep, and clean shutdown with signals.
Read More →Turning an embedded C program into a systemd service on Raspberry Pi OS Lite so it starts on every boot, restarts on crash and logs to the journal, plus how to live with it while you deploy and debug.
Read More →Cross-compiling C for the Raspberry Pi on Windows with the Linaro arm-linux-gnueabihf toolchain, deploying over SSH and remote-debugging with gdbserver, all from CMakeLists.txt and CMakePresets.json with one command.
Read More →Reading the Raspberry Pi kernel log with dmesg, understanding kernel space vs user space, mapping the project's GPIO pins, and blinking the ACT LED and driving a GPIO pin over SSH with zero code.
Read More →Booting a Raspberry Pi 3 B+ with a monitor exactly once: reading the kernel boot messages, logging in, finding the Pi's IP address, and connecting from the PC over SSH so the monitor never comes back.
Read More →Using Raspberry Pi Imager to flash Raspberry Pi OS Lite (32-bit) onto a Raspberry Pi 3 B+ SD card and pre-configure the hostname, user, Wi-Fi and SSH for a fully headless setup, before the first boot.
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Adding GoogleTest to an Embedded Linux C project: test frame.c on the PC with a separate CMake test folder, FetchContent, extern "C", a fixture that resets the shared frame, CMake presets, and a one-click VS Code test task.
Read More →send.py, the host-app side of the UDPRx task: build a 16-byte WRITE frame with struct.pack, send it unicast to the board's IP on port 5001, confirm it in listen.py and Wireshark, send from a second PC, and fix it when nothing happens.
Read More →udprx.c, the task that lets the board listen: bind to port 5001, block in recvfrom, accept WRITE frames from any PC, update control_reg with ntohl and get, change, set, hand it to TODO FPGA hooks, and stop a blocked thread cleanly with shutdown().
Read More →A Wireshark demo for the UDPTx task: capture on the PC, filter on port 5001, and read the 16-byte frame byte by byte to confirm the header, control code, big-endian order, broadcast destination, and send interval.
Read More →udptx.c, the task that puts the frame on the network: a UDP socket with SO_BROADCAST, a pthread that copies the shared frame, converts it to network byte order with htonl, and sends it with sendto, plus two bugs I left in and will fix next.
Read More →frame.h and frame.c: a 16-byte packet built from four UINT32 fields, a header marker and control codes that identify it on the wire, and a mutex-protected shared copy that the network tasks read and write as one piece.
Read More →hwalive.c, the code behind the LED heartbeat: a pthread that blinks HPS_LED0 once a second through sysfs, with write() instead of buffered streams, an lseek before every write, and start and stop paths that always leave the LED off and the file closed.
Read More →hwalive.h, the header for a heartbeat you can see: a pthread task that blinks HPS_LED0 on the DE10-Nano through sysfs, with a one-second interval, a cached file descriptor, and cleanup that leaves the LED off.
Read More →swalive.c, the code behind the heartbeat header: a pthread that prints a cycle counter and HH:MM:SS uptime every five seconds, uses CLOCK_MONOTONIC so NTP can't break it, line-buffers stdout so it never goes quiet in a log, and shuts down in about a second.
Read More →The first real task in the project: swalive.h, the header for a heartbeat thread that proves the software is still running, explained line by line, from the include guard to the volatile running flag.
Read More →Before the first task, one tiny shared header: types.h, which gives the project INT32, UINT32, and BOOLEAN names built on stdint.h so every file agrees on exactly how big each value is.
Read More →The payoff for the whole setup series: a launch.json that builds, deploys, starts gdbserver, and drops you into VS Code's debugger at main() on the DE10-Nano, all from F5.
Read More →The last link in the chain: a background tasks.json task that SSHes into the DE10-Nano, starts gdbserver, and tells VS Code it's ready when it sees
Read More →A tasks.json deploy task that builds first, then uses scp to copy the binary to the DE10-Nano, with every address and path pulled from settings.json.
Read More →The first link in a build, deploy, and debug chain: a tasks.json build task that runs make, puts compiler errors in the Problems panel, and runs on Ctrl+Shift+B.
Read More →Before automating deploy and debug, I put the toolchain path, board IP, user, and GDB port into .vscode/settings.json so every task reads the same seven values from one file.
Read More →Typing a long ARM gcc command every time I changed a file got old fast. Here's the small Makefile I wrote before my first real feature: the right cross-compiler, the right flags, and only rebuilding what changed.
Read More →Stop juggling an LED, a button, and a socket in one giant loop. Here's the Start/loop/Stop task pattern on POSIX threads I now build first on every embedded Linux project, including the DE10-Nano.
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Your laptop is x86, the DE10-Nano's ARM. Here's a full working setup â Makefile, tasks.json, launch.json, settings.json â that cross-compiles a C program, ships it to the board over SSH, and lets you set breakpoints and step through it live from VS Code.
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The newest-dated file on Terasic's DE10-Nano download page isn't an OS image at all â it's a reference-design bundle. Here's where the real bootable Angstrom Linux image actually lives, and what's inside it.
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Cataloguing every onboard peripheral on the DE10-Nano straight from the official User Manual â FPGA-side buttons, switches, ADC, and HDMI; HPS-side UART, accelerometer, Ethernet, and more â before writing a single line of project code.
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A comprehensive, one-page reference table mapping every P8 and P9 header pin on the BeagleBone Black to its GPIO bank/offset, Linux GPIO number, and default alternate function.
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Why I picked up the DE10-Nano Cyclone V SoC FPGA after a whole series on the BeagleBone Black â an ARM Cortex-A9 running Linux paired with FPGA fabric you program yourself.
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Moving recvfrom() inside the loop and adding a strcmp() dispatcher so a UDP command from Windows actually turns a BeagleBone Black LED on and off instead of just printing to the screen.
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Sending a C struct instead of a raw string over UDP, then triggering an independent loop on a BeagleBone Black with a single one-shot Winsock2 packet from a Windows PC.
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Enabling SO_BROADCAST on a BeagleBone Black UDP socket to reach an entire LAN subnet, then proving delivery with a Wireshark capture on a separate Windows PC.
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Building a UDP echo server and client in C with socket(), bind(), sendto(), and recvfrom() on the BeagleBone Black â the smallest working example of the Berkeley sockets API, and what actually happens (and doesn't) when a UDP packet leaves the kernel.
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Refactoring a single-LED sysfs blink program on the BeagleBone Black into a path array, a setup loop, and an array of FILE* handles â a C/C++ embedded systems example built and cross-compiled in Eclipse CDT, the smallest useful pattern for driving N identical sysfs devices from C.
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How to write a small C program that takes manual control of a BeagleBone Black USER LED through /sys/class/leds and blinks it on a 2-second loop using trigger, brightness, rewind, and fflush.
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How to translate a BeagleBone Black USER LED's datasheet pin nickname into the Linux GPIO number, then toggle it through both the raw sysfs GPIO interface and the friendlier LED class interface.
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How to wire up Eclipse on Windows, a cross-compiled ARM gdb, and gdbserver on a BeagleBone Black so you can set breakpoints and inspect variables while your code runs live on the target.
Read More →A hands-on walkthrough of debugging BeagleBone Black GPIO pins using gpioinfo and the AM335x pinmux debugfs interface.
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How to read live AM335x pinmux register values straight from the Linux kernel's debugfs interface to debug a misbehaving BeagleBone Black GPIO pin.
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A hands-on walkthrough of GPIO on the BeagleBone Black's AM3358 â pin muxing, register decoding, and reading real pin values from the Linux command line.
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Setting up Eclipse CDT, the GNU ARM toolchain, and the Remote System Explorer plugin to cross-compile C/C++ and deploy straight to a BeagleBone Black.
Read More →Most beginners skip this step and wonder why their BeagleBone Black won't boot. Here's why you need TWO SD card partitions (FAT for boot, EXT4 for root) and how to set them up in an Ubuntu VM.
Read More →You don't need separate BOOT and ROOTFS files for the BeagleBone Black â the official BeagleBoard.org image already has both. Here's how to flash it, boot from eMMC vs SD, and SSH in for the first time.
Read More →A plain-English walkthrough of the BeagleBone Black's 4-stage boot process â from the built-in ROM bootloader all the way to Linux taking over.
Read More →Exploring the STM32F446RE Nucleo-64's key components, pinout, and features to help you decide if it's the right board for embedded development.
Read More →A practical, analogy-driven breakdown of how PDDR and bitwise operators control pin direction in embedded C, no hardware background needed.
Read More →A beginner-friendly guide to running C unit tests inside Docker containers with VS Code, perfect for embedded software developers who want consistent, conflict-free builds.
Read More →Step-by-step guide to writing, compiling, and running a C program in VS Code on Windows using MinGW and the C/C++ extension.
Read More →Why safety-critical software demands 100% test coverage, and what happens when engineers cut corners on it.
Read More →A beginner's guide to Raspberry Pi embedded development with C â from hardware setup to writing and running your first program.
Read More →A beginner-friendly breakdown of whitebox testing: what it is, how it works, and why every developer should understand it.
Read More →Learn how to create TBrun test cases for C functions that take pointer arguments, step by step, with real examples.
Read More →A beginner-friendly breakdown of LDRA TBRUN white box and gray box test setup, covering theory, tool specifics, and real-world tips in plain English.
Read More →A quick MSYS2 UCRT terminal trick to syntax-check your C header files in VS Code without running a full build.
Read More →Explore the MitySOM-5CSx: A technical guide to memory mapping, LTC2945 power monitoring, and HPS/FPGA integration for embedded systems engineers.
Read More →Discover my first experience with LDRA embedded C code testing platform - from complex setup and licensing to achieving 50% code coverage with TBextremeTest.
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