![Making traffic lights | Physical Computing with Python | Python | Coding projects for kids and teens Making traffic lights | Physical Computing with Python | Python | Coding projects for kids and teens](https://projects-static.raspberrypi.org/projects/physical-computing/248971027a596f3437da45bafd2bd8a8cc35cb95/en/images/camjam1wiring.png)
Making traffic lights | Physical Computing with Python | Python | Coding projects for kids and teens
![pi 3b+ - Pi 3 Model B+ has steady red PWR LED but no green ACT LED with 2018-03-13-raspbian-stretch.img - Raspberry Pi Stack Exchange pi 3b+ - Pi 3 Model B+ has steady red PWR LED but no green ACT LED with 2018-03-13-raspbian-stretch.img - Raspberry Pi Stack Exchange](https://i.stack.imgur.com/cuukk.jpg)
pi 3b+ - Pi 3 Model B+ has steady red PWR LED but no green ACT LED with 2018-03-13-raspbian-stretch.img - Raspberry Pi Stack Exchange
![Help, does anyone know what's the problem here? Green light blinks four times at start then only get a solid red after, preloaded with noobs in sd card : r/RASPBERRY_PI_PROJECTS Help, does anyone know what's the problem here? Green light blinks four times at start then only get a solid red after, preloaded with noobs in sd card : r/RASPBERRY_PI_PROJECTS](https://external-preview.redd.it/2XHsKRp6Er-ObDxbYCAy4QsgffNrUyEcjGZilZOQo74.png?format=pjpg&auto=webp&s=d38e081c9dcd3384d3e39f082fdcd722f333dd46)
Help, does anyone know what's the problem here? Green light blinks four times at start then only get a solid red after, preloaded with noobs in sd card : r/RASPBERRY_PI_PROJECTS
![Max7219 Dot Matrix Module Red Light For Arduino Microcontroller Raspberry Pi 4 In 1 Display With 5pin Dupont Line - Integrated Circuits - AliExpress Max7219 Dot Matrix Module Red Light For Arduino Microcontroller Raspberry Pi 4 In 1 Display With 5pin Dupont Line - Integrated Circuits - AliExpress](https://ae01.alicdn.com/kf/H58976c2ffa70432daad5c2a61b98e6c1S/MAX7219-Dot-Matrix-Module-Red-Light-for-Arduino-Microcontroller-Raspberry-Pi-4-in-1-Display-with.jpg_Q90.jpg_.webp)