Questions tagged [pi-4]

For questions that apply specifically to the Raspberry Pi 4 and not other/all models.

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3
votes
2answers
2k views

DS18B20 Temperature Sensor - Rpi 3/4 Driver, Wiring, Detection, and Python Programming

I am new in raspberry pi. In my research project, I would like to monitor ground temperature at 60 points. My team decided to set a monitoring system using raspberry pi. As a preliminary test, I ...
26
votes
6answers
61k views

Choosing a Pi4 power supply

I'm trying to decide what is the best option for powering a Pi4. The specs mention for a minimum of 3A. Let's consider we would also like to connect a 2.5" drive to the Pi4. Could someone more ...
11
votes
2answers
14k views

What is the correct way to connect serial console on RPi4 Model B?

My config.txt has: dtoverlay=pi3-disable-bt enable_uart=1 at the end and my cmdline.txt has: root=/dev/mmcblk0p2 rootwait console=tty1 console=ttyAMA0,115200 And here's how I've connected it: I ...
9
votes
2answers
6k views

Use MacBook charger for Raspberry Pi 4

I am using the official 15.3W USB-C Power Supply to power up my Raspberry Pi 4. I got my self a second Raspberry Pi 4 but I haven't bought the power supply yet. Would I be able to use the Macbook ...
0
votes
3answers
823 views

how to copy sd-card whithout copying the unallocated space

I have a 32Gb SD card and I want to make a light copy of my os to make it work on a 16Gb SDcard. I wanted to copy just the allocated space so I used gparted to resize my rootfs partition. after that ...
14
votes
1answer
10k views

Can the Pi 4 power 2 external USB 3 HDDs?

I would like to connect two external 2.5 HDDs a Pi 4. Can the Pi 4 power two of them at once? This is the model I have in mind: WD 2TB Elements
1
vote
1answer
1k views

How can Rpi4B use UART to read and analyze received data at a 3DR FPV Air Radio Module?

I am trying to set up the FPV telemetry radios (Air and Ground Module 433MHz). I have connected the Ground module to my laptop (USB) and air module to Raspberry Pi 4 UART pins. Using Mission planner ...
1
vote
1answer
718 views

How can Rpi4B python UART talk to XY PWM Signal Generators?

Currently I am trying to automate a coil winding machine using stepper motors. I wrote a Python code to send frequencies to the stepper motors. But for some reason, the frequencies produced by ...
5
votes
2answers
2k views

How to make a splitter cable for the USB2 OTG port on the RPi 4B?

According to the answer to Where is the USB2 OTG port on the RPi 4 Model B located? the Raspberry Pi 4B has a "hidden" OTG port in the USB-C power connector. I found at Very simple OTG on pi4 and at 4 ...
5
votes
2answers
2k views

RPi 4 consumes 2.5W when shut down

My RPi 4 consumes about 0.5A after executing sudo halt, while according to this post it should draw at least an order of magnitude less (0.069A). The green LED blinks several times then goes off, but ...
3
votes
4answers
6k views

What is Rpi's I2C Maximum Speed?

The raspberry pi 3 B has a fixed i2c speed of 100kHz because of productions errors. I assumed that they have fixed it in the new version Raspberry pi 4, but of course there have been newer standards ...
2
votes
3answers
10k views

Why doesn't the RPi 4 power on when RUN pin is grounded?

I'm trying to power on a RPi 4 using the RUN pin. The RPi is runing LibreELEC (Leia) 9.2 ALPHA1. I tried shutting down the RPi from LibreELEC's GUI, then grounding the RUN pin for a second by ...
11
votes
5answers
13k views

Where is the USB2 OTG port on the RPi 4 Model B located?

According to this answer the Raspberry Pi 4 Model B has a total of five USB ports (two USB3 host, two USB2 host, one USB2 OTG). Where is the fifth USB2 OTG port located and how can I use it? Can I ...
5
votes
3answers
877 views

Serial output in case of no OS

I am using the raspberry pi 4. I have no screen connected to the raspberry pi, I do everything trough ethernet cable. I am currently changing kernels and thus sometimes I cannot boot, since I created ...
2
votes
1answer
591 views

How to verify id of installed firmware?

The release notes for example to date 2019-07-10 shows * Linux kernel 4.19.57 * Raspberry Pi firmware cb3a32adf39f45a49be454e30c7464920ad7c605 After an update I can verify the current kernel version ...
2
votes
2answers
7k views

Can I run Raspbian Stretch on Pi 4?

According to the article, there is a yellow checkmark for Pi 4 for Stretch (if it is upgraded to the 2019-04-08 release). I'm curious what limitations the Pi 4 has in this state.
4
votes
3answers
9k views

Is the gpio readall command compatible with RPi 4?

It's already a while since I got my Pi 4, but never used the gpio readall command until yesterday. I have run into an interesting error. pi@raspberrypi:~ $ gpio readall Oops - unable to determine ...
3
votes
2answers
496 views

execute Python file on Systemstart

I want to run a simple python script like: import webbrowser webbrowser.open('http://google.com/', new=2) when the startup progress of my RPI 4 is finished. I tried something like "[How to run a ...
2
votes
3answers
590 views

Does Raspberry Pi 4 consume considerable amount of power in soft-off state?

In the Start menu (you know, the fruit button at the top-left corner), I clicked shutdown. I did not unplug the USB-C power cable. The red light was still on, but I thought it was like the sleep light ...
1
vote
1answer
1k views

How to make Raspberry Pi 4 as "WIFI" -> "Ethernet" adaptor without add any USB component?

Considering the following situation: There is a available WIFI source which is connect to Internet, and there is a desktop computer which is lack of WIFI adapter. Then a Raspberry Pi 4 is provided ...
1
vote
2answers
4k views

Error Installing Tensorflow in Raspberry Pi 4

Help I'm new to this and I cannot install Tensorflow on Raspberry Pi 4 4GB. Current Python version: Python 3.7.3 Pip version : pip 19.2.3 I tried typing pip install --upgrade tensorflow and pip3 ...
45
votes
13answers
121k views

64-bit OS on Raspberry Pi 4

Looking for a 64-bit version of Linux for the Raspberry Pi 4. I'm aware that support under Ubuntu Mate is in the works, apparently Ubuntu Server works but it limited to using 1 GB of RAM. Are there ...
6
votes
4answers
21k views

Can Rpi4B power external / portable USB HDD / SSD?

I was not able to power an external HD directly from a Raspberry pi 3 (the HD was constantly complaining about a lack of power). Would a Raspberry Pi 4 be able to power a portable hard drive (using ...
1
vote
0answers
392 views

HDMI power circuit on the Raspberry Pi 4

The previous models of the Raspberry Pi used different circuits to connect its 5 V power rail to the HDMI connector, i.e. How much current can I draw from each model's HDMI socket? Especially the ...
5
votes
2answers
5k views

PI 4 sometimes doesn't boot after rebooting from command line [closed]

I have a new Raspberry Pi 4 connected to a motherboard that supplies very stable voltage and current to the Pi. I flashed an SD card with the latest distro and realized that sometimes when I run ...
1
vote
3answers
90 views

Reboot not starting python app but executing runs with no Errors

I'm running a bell app connected by ENet between two RPI 4. The button end works well, but the server end only works when I sign in to activate it. How do I get it to start at start-up in Crontab? @...
1
vote
2answers
379 views

How can Rpi4B python read negative result values of the SPI ADS1256 24 bit ADC?

I am trying to get negative ADC value by giving -2.5 v to AD/DA high precision expansion board with Raspberry Pi 4. I am using python programming with twos complement of buffer size 200, unfortunately,...
29
votes
1answer
12k views

Does the Pi 4 resolve the Ethernet+USB bottleneck issue of past versions?

The Pi 3 (and previous models) had an issue of bottlenecked bandwidth when using Ethernet and USB simultaneously. Is this resolved in the Pi 4?
9
votes
1answer
26k views

Powering the Pi 4 - safe voltage levels and current requirements

How to safely power the Pi 4, more specifically: What voltage levels are safe to power the Pi 4 via the USB-C connector or via the GPIO header? What are the current requirements? What Power ...
5
votes
2answers
6k views

Setting up Raspberry Pi 4B to be a wifi access point

I want my Raspberry Pi 4B to create a wireless network that connects to my router, without using any external devices to assist the pi (ie. a secondary router or an antennae that would connect to the ...
5
votes
2answers
8k views

Raspberry Pi4 Error while using 2 USB cameras, VIDIOC_QBUF: Invalid argument

I'm using Python OpenCV to read from 2 USB webcams on a Raspberry Pi4. If I'm using either of the camera individually they work fine. As soon as I initialize both cameras in the script as following: ...
3
votes
7answers
33k views

How much temperature is normal temperature for Raspberry Pi 4

I am running a haarcascade based face detection and face recognition on Raspberry Pi 4. The CPU temperature rises to 83-84C. So I have installed a heat sink and 5v pi fan. After installing this, I ...
6
votes
2answers
989 views

What Revision(s) does cat /proc/cpuinfo return on the new Pi 4 1/2/4GB?

To enhance my bash script decoding the Revision returned by cat /proc/cpuinfo I'd like to know what the RaspBerry Pi 4 codes for ModelName,Processor and Memory are. (my own one is still underway) ...
5
votes
1answer
2k views

What is the purpose of PD_SENSE in the Raspberry Pi 4 power circuit?

Here the schematics of the USB-C power input of the Pi 4 : You can see that there is a resistor connected to the USB_CC lines of the USC-C socket, the other side is labelled PD_SENSE and is going ...
4
votes
2answers
882 views

Rpi4B power connector SMD components damaged. How to replace it?

I broke what looks to be either a diode, capacitor or resistor on the board near the power connector of the pi 4B and I want to try to replace the surface mounted component. I know the chances are ...
3
votes
1answer
360 views

Unstable rPi 4B after rpi-update

My raspberry pi model 4B was having frequent WIFI issues. I read that a firmware update was made to address this, so I thought I would upgrade the firmware. After doing sudo rpi-update I now have ...
2
votes
1answer
2k views

What is the configuration of the 4-pole A/V jack on the Pi 4?

What is the configuration of the combined analogue audio and composite video 3.5mm jack on a Raspberry Pi 4?
2
votes
1answer
616 views

How to connect Rpi4B to a HDMI Touch Screen?

I have recently invested in a HDMI touchscreen from Amazon, and a Raspberry Pi 4, For the touchscreen to work it must be connected via GPIO, however my pi cannot supply enough power to it from my usb ...
2
votes
3answers
1k views

Can I use Raspberry Pi 3 SD card on Pi 4?

I'd like to move to the new raspberry pi because I need more performance. The current sd card I used on pi 2, ane now pi 3, and I'd like to ask if anyone tried running his pi 3 raspbian on pi 4 by ...
2
votes
0answers
231 views

Raspberry pi 4 stuck on rainbow screen, green LED flashes 4 times

I have install latest(2020-05-27) raspberry pi image 32-bit. And it gets on rainbow screen on both outputs, red lights is on, while green lights flashes 4 times. When I turn on raspberry pi with out ...
2
votes
1answer
414 views

Model 4B Running Hot

Here is my hardware/software setup: Model 4B with 4GB of RAM. Official 5V power supply (North American socket) Official case with provided heatsinks Ubuntu 20.04 (Most recent LTS, came out April 2020)...
2
votes
1answer
134 views

How can Rpi communicate with Arduino in RF (Radio Frequency), Say Using nRFL2401+?

I need to transmit and receive data between Rpi and Arduino, in RF (Radio Frequency). I must say I have next to zero experience in this field. So any help, papers, documentation, book or manual would ...
1
vote
2answers
72 views

Raspberry pi 4 rebooted without notice

I have a raspberry pi 4 that runs a samba server (+ 2TB HDD) and it suddenly rebooted. I use a pretty big heatsink to keep the pi cool and I use the official raspberry pi power supply.
1
vote
0answers
1k views

Did anyone get a Miracast display working with a Pi 4?

I have tried using miraclecast, which builds without problems but won't find a Miracast screen which my Windows 10 laptop has no trouble to work with. pi@raspberrypi:~ $ sudo service wpa_supplicant ...
1
vote
1answer
451 views

linux-perf-5.4 for amd64

My raspi4/8GB is running the 64bit version of Raspberry Pi OS. The linux kernel is 5.4, but perf is only linux-perf-4.19. There seems to be no matching perf version. What am I doing wrong?
1
vote
1answer
398 views

HDMI display rotated, but not X keeps landscape aspect ratio

PI 4 I've added display_hdmi_rotate=1 to /boot/config.txt and the display rotates. I've also tried =3 with the same results described below. During boot the Raspberry Pi Desktop welcome splash is ...
1
vote
1answer
635 views

RPi4B PCA9685 PWM Controlling Many Servos

I have this RPi3 that I am running a bunch codes on it. It is communicating with a server and also I have python supervisor running on it. Now I am trying to set up the same system on RPi4. For some ...
1
vote
1answer
1k views

Pi 4 Model B: failed to connect to network

I bought Pi 4 Model B recently from an official seller. Then I installed raspberry pi OS 32 bit as it was mentioned on site. I completed the installation setup and everything was working fine! Wi-Fi ...
0
votes
1answer
780 views

Connecting Various Devices Using Bluetooth as Serial Port

I managed to connect a sensor via Bluetooth to a serial port on the Raspberry Pi 4 by doing the following: First, I added the SP profile to the Raspberry by opening and editing the following file: ...
0
votes
2answers
329 views

raspberry pi 4 suddenly won't recognize nvme on USB3 port

I'm running ubuntu 20.10 arm64 on Raspberry Pi 4b. I was booting from a western digital NVMe drive in a USB-to-NVMe adapter/enclosure thing attached to the USB3 port. This has been working fine for ...