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73 votes
Accepted

How do I make serial work on the Raspberry Pi3 (PiZeroW, Pi4 or later models)

This answer is still correct, and explains in more detail the nature of the changes, but most users of current Raspbian should just run sudo raspi-config Select Interfacing Options / Serial then ...
Milliways's user avatar
  • 60.3k
30 votes

WiFi won't start

I found wpa_supplicant to be super confusing to work with until I figured out how to see its debug messages by running it manually. sudo killall wpa_supplicant sudo wpa_supplicant -c/etc/...
Leopd's user avatar
  • 403
26 votes
Accepted

How to setup the Raspberry Pi 3 onboard WiFi for Ubuntu Server 18.04 with netplan?

The steps below were found to provide a persistent WiFi setup using netplan with Ubuntu Server 18.04 ubuntu-18.04.2-preinstalled-server-arm64+raspi3.img.xz image on a Raspberry Pi 3 B+. Update system: ...
marc-medley's user avatar
21 votes

How do I make serial work on the Raspberry Pi3 (PiZeroW, Pi4 or later models)

finally this got work for my pi3 (os: debian jessie) please follow these 6 steps carefully. Step 1 - Install Raspbian Jessie onto a SD card and boot the Pi when connected to a network Login via ...
naseer mohammad's user avatar
16 votes
Accepted

Why am I getting a rainbow screen and flashing red PWR LED with a new Raspberry Pi 3B+?

I've made this answer to summarize the experience to this issue. We are talking about Raspberry Pi 3 Model B+, released on 2018-03-14. It has some new and updated features compared to Raspberry Pi 3 ...
Ingo's user avatar
  • 42.2k
15 votes

How do I make serial work on the Raspberry Pi3 (PiZeroW, Pi4 or later models)

Raspberry Pi4 UART The BCM2711 used in the Raspberry Pi 4 Model B, the Raspberry Pi 400, and the Raspberry Pi Compute Module 4 has 4 additional UART (uart2-uart5) in addition to uart0/1 on the older ...
Milliways's user avatar
  • 60.3k
14 votes

Is it possible to simultaneously use the dual band(2.4 Ghz and 5 Ghz) of Raspberry pi 3 B+ to create an AP?

It is exactly determined what the Raspberry Pi 3B+ is able to do with its WiFi on-board device. With the command iw you can show what interface combinations are possible. Just execute $ sudo iw list | ...
Ingo's user avatar
  • 42.2k
14 votes

Is there a way to remove old files without relying on internet time service?

Since you don't have Internet NTP, the file timestamps are meaningless, being reset to the Pi's "/etc/fake-hwclock.data" time whenever the system is booted. If the daily data file(s) have a ...
dave58's user avatar
  • 345
13 votes
Accepted

How fast can GPIO pins toggle?

There are some benchmarks from Henner Zeller's repository on GitHub which claimed that directly outputting data to the GPIO could achieve up to 65.8 MHz on a Raspberry Pi 3 (not B+, mind, but I ...
Aurora0001's user avatar
  • 6,328
11 votes

How do I make serial work on the Raspberry Pi3 (PiZeroW, Pi4 or later models)

Naseer's answer is correct but a bit elaborate if you just flashed the latest rasbian. All I needed to do, is just to add the following line to my config.txt (from e.g. windows where you plug in the ...
Arnout's user avatar
  • 211
11 votes
Accepted

Raspbian 8 on Raspberry Pi 3 B+

It's really advisable to upgrade to stretch, but if you want/need to stay with Jessie, follow these steps to get it working: You'll need to do this first step on a pi3 (not plus): Update the ...
Mike Redrobe's user avatar
10 votes
Accepted

What are the functions of the test pads on the Pi 3B/3B+?

Testing points on a Raspberry Pi 3B and 3B+: PP1 VCC +5V (from micro USB receptacle) PP2 VCC +5V (from micro USB receptacle) PP3 GND PP4 GND PP5 GND PP6 GND PP7 5V after polyfuse PP8 ...
Ghanima's user avatar
  • 15.9k
10 votes

How to program active cooling connected to GPIO

It is simple to control a small fan with the Pi GPIO. I use a simple transistor circuit (with only 3 inexpensive components). I use the Pi 5V pin to power my fan, but this could be used with an ...
Milliways's user avatar
  • 60.3k
10 votes
Accepted

Shorted 3.3v + 5v together. Is it possible to repair?

A little instruction for people who want to resolder MXL7704-R3. Order in aliexpress MXL7704-R3 (2.5$ - 3.5$). You must have hot air rework station which can heat up to 350 degrees Celsius to remove ...
snex's user avatar
  • 254
10 votes
Accepted

RP Automatic Updates

In fact Raspbian does have daily upgrades enabled by default; to check: systemctl status apt-daily-upgrade.timer The bit to play attention to is in the second line of output. Between the two semi-...
goldilocks's user avatar
  • 59.1k
9 votes

Change PI 3 against PI 3 B+

Quite simply, extra power. The lightning symbol means the pi isn't getting enough power so try another power source preferably one rated at least 2.5A. The model B+ has slightly more power ...
John Hawthorne's user avatar
9 votes
Accepted

Netbooting multiple "workers" RPi from a "master" RPi

Here is a solution with netbooting using sytemd-networkd. Network booting works only for the wired adapter. Booting over wireless LAN is not supported 1. It is also important that there is already ...
Ingo's user avatar
  • 42.2k
9 votes
Accepted

Switch between wifi client and access point without reboot

Access point and client mode are both running as services so we should use systemd-networkd to switch off one service and switch on the other. With its options we are able to do it without rebooting. ...
Ingo's user avatar
  • 42.2k
9 votes
Accepted

PoE hat fan activation on OS other than Raspbian

I'm using Ubuntu Server 20.04 LTS. The dtparams setting does not work, instead you need a udev rule. The fan config is in /sys/class/thermal/cooling_device0/, if you cat /sys/class/thermal/...
Luke Channings's user avatar
9 votes
Accepted

RPI3B+: What are the four components below the HDMI connector called?

While the official Raspberry schematics don't tell a thing about these components we can learn from the picture of the PCB that they are connected to the paired pins 1 and 3, 4 and 6, 7 and 9, 10 and ...
Ghanima's user avatar
  • 15.9k
9 votes

RaspberryPi 3 B+: RPi restart whenever I tried to run two webcams simultaneously

No one is mentioning that the Maximum total USB peripheral current draw on a rpi 3b+ is 1.2A (power requirements) Having said that your current psu is enough. If the cameras are indeed drawing more ...
papatrexas's user avatar
9 votes
Accepted

Text editor for Raspbian Lite

The simplest way would be to use nano. It comes as standard on the majority of Linux distributions. To use it, simply type nano followed by the name/path to the file you want to edit. For example, to ...
rohtua's user avatar
  • 459
9 votes
Accepted

Remmina does not connect to Raspberry Pi Bullseye after RealVNC-server update

I'd recommend using RealVNC's VNC Viewer - it's free to use and guaranteed to work with the RealVNC VNC Server. You can download it here: https://www.realvnc.com/en/connect/download/viewer/ However, ...
jackyaz's user avatar
  • 106
8 votes
Accepted

Unable to detect cam module in raspberry pi 3 b+

You need to run sudo raspi-config and enable the camera from there before you can use it. The main menu should have an "Interfacing Options" submenu (probably #5). From there the option to ...
goldilocks's user avatar
  • 59.1k
8 votes
Accepted

Run steam link automatically when starting raspbian

/etc/init.d was deprecated with Jessie. Everything is done with systemd now on Raspbian Stretch (and lots of other distros). There's six places where you can easily get things running at boot time. ...
Dougie's user avatar
  • 5,321
8 votes
Accepted

Installing libraries via pip is taking forever. Raspberry pi 3b+

Building scipy from source takes about 1hr20. Pre-compiled wheels are available from piwheels.org, so you can install it from there without building yourself. Raspbian Stretch is pre-configured to ...
ben_nuttall's user avatar
  • 2,461
8 votes
Accepted

Is it safe to power my external hard drive with a Raspberry Pi 3 B+ USB port?

You SHOULD be able to power a USB HDD from the Pi3B+ as the USB ports can supply 1.2A. HOWEVER, I and others have found that this is often unreliable - this seems to be due to transient voltage drop ...
Milliways's user avatar
  • 60.3k
8 votes

Shorted 3.3v + 5v together. Is it possible to repair?

I did the exact same thing: Shortened the 5V and 3V3 rail by accident (with a probe). In my case it was sufficient to replace the Power-Management-Chip, which is indeed available. I used aliexpress ...
schlimmchen's user avatar
8 votes
Accepted

How to install the latest version of neovim?

Official documentation recommend using AppImage in any Linux distro: The Releases page provides an AppImage that runs on most Linux systems. No installation is needed, just download nvim.appimage and ...
logoff's user avatar
  • 195

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