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JetCar Mini Self-Driving Project

JetCar is a mini self-driving car project developed based on NVIDIA Jetson Nano. It can autonomously navigate on street maps, following the instructions of stop signs and directional arrows. This project is suitable for makers with some experience, providing complete guidance and requiring over 8 days to complete.

The hardware components of JetCar include Adafruit 16-channel PWM/Servo expansion board, Jetson Nano development kit, cooling fan, WiFi onboard device, Molex WiFi antenna, Adafruit PiOLED display, gear motor, H-bridge circuit board, camera, servo motor, wheels, and power bank, etc. In terms of software, tools such as Fusion 360, Microsoft Visual Studio, Google Colab, NVIDIA Jetpack SDK, and Jupyter Notebook are used.

JetCar can recognize directional arrows, stop text, and stop lines on the street through machine learning technology. Its model architecture is U-Net, which can process generated intuitive category images in the firmware, which is written in Python and controlled via Jupyter notebook. Users can connect to the car from the host computer via WiFi and simply request a direction change at the next intersection. However, it will only turn when the directional arrows on the street do not restrict the direction.

This project includes mechanical design, electronic design, firmware and data preparation, model training, and tools for street map generation. All source code and binary files have been published on GitHub, and the documentation details the production process of all components, aimed at helping anyone make this small car at home, try it out, and modify it.

GitHub address: https://github.com/StefansAI/JetCar

Source: https://www.hackster.io/stefanw1/jetcar-the-mini-self-driving-car-project-f83bc8

Playing Audio from SPI Flash with Microcontrollers

This project demonstrates how to use the PWM output of a microcontroller to drive a speaker and play audio stored in an SPI flash chip.

By encoding the audio at 8-bit resolution, with a sampling rate of 8 kHz, 32 Mb (4 MB) of memory is sufficient to store approximately 8 minutes of raw audio. The project uses a W25Q32 breakout board, which costs about $2. Compared to similar projects using SD cards, this method is more advantageous for simple projects, as it only requires adding one cheap component.

Software:

• Arduino code
• AVR64DD32 code (more advanced 8-bit AVR microcontroller)

Hardware:

• Microcontroller
• SPI flash chip (W25Q32)
• Speaker
• LM386 audio amplifier
• UPDI (for programming modern AVR microcontrollers)
• Additional circuit for power filtering and audio amplification
• 10-bit DAC (for modern 8-bit AVR)

The project not only details how to play audio using Arduino and AVR microcontrollers, but also provides corresponding source code links for further study. Additionally, video examples demonstrate the audio playback process, allowing readers to better understand the implementation of the project. These techniques can be applied to embedded projects that require playing stored audio.

Source: https://swharden.com/blog/2023-08-26-spi-flash-audio/

Smart Plant Growth Monitor

This is a lovely smart device designed for plant enthusiasts, capable of monitoring soil moisture and surrounding environment to ensure plants grow under optimal conditions.

This device utilizes capacitive sensing technology to measure soil moisture and is equipped with a low-power electronic paper display, which can not only update information in a timely manner but also consumes very little power.

Additionally, it features a built-in BME688 sensor that can monitor air quality and CO2 levels, helping you take better care of your plants.

Software and Hardware:

• ESP32-C6 chip: built-in 4MB flash
• AEM10941: solar energy harvesting
• USB-C interface: for charging and programming
• 1.54-inch electronic paper display
• BME688 environmental sensor
• Built-in soil moisture sensor
• Battery voltage detection
• 1A charging rate via USB
• 3.7V lithium polymer battery
• KiCAD 7.0.5: software for designing circuit boards
• 3D printer: for making the device housing
• Nordic PPK2 and Joulescope: for measuring power consumption and solar charging current
• PCBWay: provides PCB printing and assembly services

The detailed circuit diagram and component list of this project can be found on the Plantpal GitHub page. Additionally, the device’s housing model can be designed using TinkerCAD and printed with any standard 3D printer.

GitHub link: https://github.com/teapotlaboratories/plantpal

Source: https://hackaday.io/project/194851-plantpal-your-pal-in-plant-care

Arduino UNO Style 8051 Development Board

Electronics enthusiast “Electro Boy” perfectly combines classic and innovation, creating a development board based on Arduino UNO. The core of this development board is a modern version of the legendary Intel 8051 microcontroller – Microchip’s AT89S52-24PU chip. This chip retains the classic features of the 8051 while adding 8kB of flash memory for program storage, making it more powerful. The board design is simple, requiring very few external components, including some passive components, LED lights, a 12MHz crystal oscillator, a 5V voltage regulator connected to a 12V DC power inlet, and a USB Type-C interface (for power only). Electro Boy’s design is inspired by Arduino UNO, creating a PCB with all controllers, neatly arranging the programming header and all four ports in a dual header layout. The design drawings and Gerber files of the PCB have been published on Hackster website under the GNU General Public License 3 for all enthusiasts to use for free.

Source: https://www.hackster.io/news/electro-boy-blends-new-and-old-builds-an-arduino-uno-style-board-for-the-classic-intel-8051-9f4c70ca454f

Homemade JBC Soldering Station Selector

While soldering operations are conceptually simple, they involve many details, and using the right tools is crucial to improving work speed and product quality. High-quality soldering stations typically offer multiple hot end options, but switching from a simple pencil-type soldering tip to hot tweezers often requires unplugging and replugging, while ensuring that the soldering station can correctly recognize the new tool. Lajt has three soldering tools and a single-output soldering station, and his solution is to create a homemade three-way front-end selector, allowing easy selection of the tools connected to the soldering station via buttons.

Software and Hardware used in the project:

• Arduino Pro mini
• Relay
• JBC soldering station
• Different hot end options (simple pencil-type soldering tip, hot tweezers, etc.)

Source: https://hackaday.com/2024/02/29/a-3-tool-selector-box-for-a-jbc-soldering-station/

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