All Questions

0
votes
0answers
15 views

Why no result from os.popen() when script is run from crontab?

When I run this Python3 script from the command line or from Thonny I get correct results. When I run it through crontab the variables ipaddress an ssid stay empty. Can anyone tell me why? Any ...
0
votes
0answers
12 views

Still getting problem : “Network Error : Connection refused” problem

I am facing this problem even after trying many recommendations from this site. I am using windows 10, raspbian stretch lite(2019)/raspbian stretch(Nov2018) and I don't have a monitor. Earlier I could ...
1
vote
1answer
24 views

How do I find the IP address of my Raspberry Pi 3B+

I don't have a HDMI screen, nor do I have access to the router. From what Ive been told, it has Kali installed. I am connecting the Raspb directly to the computer with a Ethernet cable. I have tried ...
0
votes
0answers
15 views

How can I disable the serial debugging console?

I am using raspberry pi 3b model with android things. I need to attach GPS module NEO6mv2 with the pi. How can I disable the serial debugging console?
1
vote
0answers
6 views

Touchscreen xinput calibration not working

I want to calibrate a touchscreen named "eGalax Inc. USB TouchController" on my Raspberry Pi. I think X and Y axes of the touchscreen are inverted. I used xinput_calibrator for this purpose. When I ...
0
votes
0answers
13 views

Green LED blinks 4 times, no problem with SD card on other Raspberry, same problem with other SD card on same Raspberry

I booted and used my Raspberry for the first time yesterday. I used USB mouse, keyboard and monitor first, enabled ssh and vnc and established connections with my Windows laptop going forward. I did ...
0
votes
0answers
17 views

How to get LDR sensor reading in C language [on hold]

I am currently working on a project using laser module, a capacitor and an LDR. After looking online, I found a library in Python called GPIOZero that allows me to do this directly, as follows: from ...
2
votes
0answers
16 views

netperf command doesn't exist on raspbian

I am trying to run some tests about network on my Raspberry Pi 3 B+, and I have raspbian on it. I installed flent via apt install flent, and I ensured that non-free repository is enabled. I still can'...
0
votes
0answers
28 views

Is there a piece of hardware which enables hotplugging sensors to the breadboard?

The idea is the following: I have a Raspberry PI connected to a breadboard. To this breadboard, I would like to connect (digital and analog) sensors and actuators while the PI is running. Or remove ...
0
votes
1answer
30 views

Ethernet communication Raspberry PI and windows PC

I am working on project which involves sending datastream from raspberry pi to Windows PC. This should only be done through Ethernet link. I looked for ethernet libraries but i did not find any. Also ...
-1
votes
1answer
23 views

RASPBERRY PI Error Python GUI : “no display name and no $DISPLAY environment variable”

Hi guys I want to create a basic GUI with TKinter. This is my code from tkinter import* import tkinter.font win =Tk() win.title("Test") myFont = tkinter.font.Font( family = 'Helvetica', size = 12, ...
1
vote
1answer
27 views

Why is pigpio library not moving my servo when the same pin number works perfectly with RPi.GPIO?

I am working on a self driving rc car project and I need a servo to steer my car. As I was getting a bit jitter with RPi.GPIO I tried pigpio library. I am using a Raspbery Pi Model B. But it won't ...
-4
votes
1answer
43 views

No colors in terminal when booting raspbian in text mode [on hold]

I am booting my pi as text with autologin. Even after modifying the bashrc file in the /home/pi folder, I still see the text in white. I know that the color is enabled, because during the boot, I ...
0
votes
1answer
18 views

i got error on rpi camera. Camera is good and i still got this error

I get these error messages: mmal: mmal_vc_component_enable: failed to enable component: ENOSPC mmal: camera component couldn't be enabled mmal: main: Failed to create camera component mmal: Failed to ...
-1
votes
0answers
22 views

How to display output from a facial detection code in python on an LCD display

I have made a facial detection app using Python on RaspberryPi. The code is working fine and writing the name of the detected person on the camera's screen but what I want to do is to display the ...
0
votes
0answers
19 views

RPI 3B+, Wifi super slow (10x slower than onboard) when using USB Wifi despite huge antenna

TL;DR, usb-wifi works, but it's extremely (!) slow compared to onboard wifi, even though the dongle has a big antenna and a a better signal quality. I looked far and wide and did all I could find, but ...
0
votes
0answers
17 views

How can I update from PHP 7.0 to PHP 7.1?

My /etc/apt/sources.list file: deb http://raspbian.raspberrypi.org/raspbian/ stretch main contrib non-free rpi # Uncomment line below then 'apt-get update' to enable 'apt-get source' deb-src http://...
1
vote
1answer
20 views

Voltage dropped significantly on GPIO 4 with a relay coil

I have a Raspberry PI 3 B+, and when I activate the GPIO 4 as output and checking agains a multimeter I get its 3.3V as expected. If I connect the GPIO4 to one end of a coil (http://www....
0
votes
0answers
20 views

How does the linux kernel handle interrupts [on hold]

A few days ago I asked a question that had (probably) had to do with en interrupt being fired by an ENC28J60 chip (SPI) and messing with the UART buffer. See here. I found a software fix for this ...
0
votes
0answers
8 views

selenium.common.exceptions.WebDriverException: Message: connection refused

I ran a program with selenium from selenium import webdriver driver = webdriver.Firefox() driver.get('http://www.google.com') and this error accured Traceback (most recent call last): File "/...
-2
votes
0answers
15 views

Which one is better between `xcb` and `eglfs` on raspberry qt native built installation

I need to install and use Qt for my gui medical device (dental glazer furnace) part into my raspberry zero like this: SO I have tried cross compilation qt first which I have some problem which doesn'...
0
votes
1answer
13 views

init.d script does not run start on boot but starts manually (Raspbian)

Whenever the system starts, the zfs-import init script does not run: root@kapnet:# /etc/init.d/zfs-import status ● zfs-import.service - LSB: Import ZFS pools Loaded: loaded (/etc/init.d/zfs-import;...
1
vote
1answer
14 views

RC522 modules stop working when more than 2 are connected

So, here's a synopsis of what I am trying to do. I want to put 3 RC522 readers side by side inside of a book, facing the cover, that will be constantly on, using a Rpi zero W. When an RFID chip gets ...
0
votes
0answers
13 views

How to make mt7612u driver work on pi?

I'm trying to make my pi work with mt7612u driver, which is included in 4.19.y branch. But just got following error: [ 34.271279] mt76x2u: probe of 1-1.5:1.0 failed with error -22 [ 34....
-1
votes
1answer
27 views

Play raspberry pi sound through bluetooth speaker

I have Raspbian Stretch installed on my RaspBerry Pi Model 3B+. I paired the speaker using bluetoothctl, but I cannot see it in raspi-config (Advanced Options -> Audio) list. Also I tried several ...
0
votes
0answers
25 views

how to send data from rasberry pi 3 to android or smartphone? [on hold]

please help me. how to send data / capture/image from rasberry pi to android or smartphone device rasberry pi 3 webcam smartpohone adroid xiomi note 4
1
vote
0answers
24 views

How do I know my PCF8951 is not broken?

I am using some PCF8951 board like this: I remove all the jumper, like this: This is every thing: Then I plug two senor board to this board. Everything plugs into AIN0 will get the correct value. ...
2
votes
1answer
28 views

How to connect 3V3 UART logic level to the 5 V RS232 C logic level?

How to connect the 3.3 V Raspberry Pi UART logic level to the 5 volt RS232 C logic level?
9
votes
4answers
4k views

What is the highest voltage from the power supply a Raspberry Pi 3 B can handle without getting damaged?

I am using Android things on Raspberry Pi 3 B with a 7-inch touch screen. Currently, I always see a yellow thunder bolt sign on the screen which means that the Raspberry Pi isn't receiving a high ...
-1
votes
0answers
11 views

Failure to build QT5 5.12.3 on Raspberry Pi zero : sub-plugins-make_first Error 2

Following the instructions in https://www.tal.org/tutorials/building-qt-512-raspberry-pi,: wget http://download.qt.io/official_releases/qt/5.12/5.12.3/single/qt-everywhere-src-5.12.3.tar.xz tar xf qt-...
1
vote
0answers
30 views

Getting button click type

I've been looking for a while to how to get the kind of click of a button on GPIO. Is it a single click? Double? Triple or more? Is it a long click? a very long click? a combination of them? I haven'...
2
votes
1answer
35 views

Simple python RFID (RC522) authentication system not working

I am a realative RPi noob so forgive me if this is a simple problem. I am making a keycard system with the RC522 reader, and I have everything wired up correctly. It works with writing and reading ...
-3
votes
0answers
30 views

Buying a new and different buggy chassis

I successfully made the buggy from the raspberry pi website: https://projects.raspberrypi.org/en/projects/build-a-buggy and I am happy with it because it works and everything. BUT the chassis is made ...
0
votes
0answers
15 views

Prevent Automount of Camera

I am about to build a photobooth with my Canon DSLR and a RasPi. Now when I plug the USB of the camera, raspbian will automatically mount it and prevent my command line scripts from using it (device ...
0
votes
0answers
29 views

raspberry pi3 + fingerprint

I'm looking for a way to connect fingerprint scanner with raspberry pi3 using python. I'd like to use only gpio or hat (not usb) interface. I'm searching for a while without figured out, so I've ...
-3
votes
1answer
35 views

software copy protection in raspberry pi [on hold]

i need to ensure that even if my executable C/C++ codes are copied to another raspberry Pi (dumping the SDcard), they will not run there. what are the possible ways to do this. Update: it seems ...
0
votes
3answers
42 views

No route to host problem

When I attempt to connect via SSH from the Pi (client) to another machine (server) on a port other than 22 I get a "No route to host" error message: Successful SSH pi@raspberrypi:/opt/pihole $ ssh ...
2
votes
2answers
25 views

Python3.7 with Numpy on Raspbian

Goal: Install Python3.7 on the Raspberry Pi. Then install Numpy for Python3.7 Found this very useful Github Gist: https://gist.github.com/SeppPenner/6a5a30ebc8f79936fa136c524417761d Ran the ...
0
votes
0answers
16 views

How can I set up video calling with out the video lagging 3-5s? (lag is local to the pi, before transmission to other clients)

I am doing video conferencing on my Raspberry Pi 3b+. I have tried both Jitsi (better) and Google Meetings but both of them have a 3-5s lag between the real world and the self-image shown on the pi (...
1
vote
1answer
36 views

Simple command line to write and read data from UART (serial) loopback

I want to connect the TX and RX pins together and from the command line echo some text into /dev/ttyAMA0 and tail the result (from somewhere). I ultimately want to communicate with an Arduino but ...
0
votes
1answer
28 views

Is it possible to toggle 3.3V and 5V header pins on and off? [duplicate]

Header Pins 1, 2, 4, 17 are labled 3V3 and 5V on the schematics but the connections to the BCM and/or regulators are not in their documents. It appears the 5V node is coming from the raw USB/external ...
-1
votes
0answers
18 views

SD Card reader not detected

I have hard shutdown the raspberry pi zero and after that, I cannot read the SD card in into it; reader (connected to my Linux OS pc). But the sd card works in the pi connected with LCD TFT 5 inches,...
0
votes
0answers
11 views

What is the best way to connect a Raspberry Pi with Firebase? [on hold]

What is the best way to connect a Raspberry Pi with Firebase?
0
votes
0answers
12 views

Failure to build QT5 5.12.3 on Raspberry Pi zero

Following the instructions in https://www.tal.org/tutorials/building-qt-512-raspberry-pi,: wget http://download.qt.io/official_releases/qt/5.12/5.12.3/single/qt-everywhere-src-5.12.3.tar.xz tar xf qt-...
1
vote
0answers
13 views

Run script or command on Pi based on Alexa voice command or skill

I'm building a power relay controller based on RPi and I want to be able to turn my whole system off by asking Alexa to shut it down. I have considered using an Alexa-controlled "smart" relay to ...
0
votes
0answers
8 views

Adding Subtitle font in OSMC

Hi I have OSMC installed on berryboot. And I want to Add my own Subtitle fonts (.ttf). I tried to locate Font file from OSMC File Manager. But I only found a file named "addons" this was the path: ...
0
votes
1answer
24 views

False Contact Closures - Do I Need Physical Pull Up Resistors to Resolve?

I'm running Raspbian Jessie 4.9.35-v7+ on a Pi 3 Model B. I cobbled together a basic python script to monitor a GPIO pin and send a network signal to a remote application, made two copies of the ...
0
votes
1answer
16 views

What does “ ad9833.c:36:2: warning: implicit declaration of function ‘bcm2835_gpio_fseL’ [-Wimplicit-function-declaration] ” mean?

I'm trying to generate signals using an AD9833 and a raspberry pi 3 model B+ but each time I build my programme I have this error message: ad9833.c:36:2: warning: implicit declaration of function ‘...
0
votes
0answers
6 views

How to start PPPD connection on boot and handle it in case of network failures?

I have to setup Quectel EC25-E hooked up to my Rasp Pi Zero. I can setup the ppp connection but manually. This is what I do: Quectel module ppp connection However, I have to make this pi headless ...
2
votes
1answer
19 views

Display IP Address on LXPanel

I'd like to print on the LXDE Pannel (LXPanel) the IP address of my Raspberry Pi, so I can have a direct view about how to connect to the Pi from another computer when I reboot it, since its IP is ...

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