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Raspberry Pi

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The collection of articles, videos, and posts on this topic.

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The Raspberry Pi Foundation works to put the power of digital making into the hands of people all over the world, so they are capable of understanding and shaping our increasingly digital world, able to solve the problems that matter to them, and equipped for the jobs of the future.

We provide low-cost, high-performance computers that people use to learn, solve problems and have fun. We provide outreach and education to help more people access computing and digital making. We develop free resources to help people learn about computing and how to make things with computers, and train educators who can guide other people to learn.

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Hi Experts,

i do have two raspberry pi, One as publisher and another one as a subscriber. It works on the local area network without internet. Data transmission and receiving, works fine and data storing into MariaDB also works fine. The issue is time. The router run locally without internet connection. If someone switch off or restart router, the system depend on router time which not synchronise online time.

To over this issue, i did add in RTC DC3231 in both raspberry with the following setup. 

#!/bin/sh
# Reset the System Clock to UTC if the hardware clock from which it
# was copied by the kernel was in localtime.

dev=$1

#if [ -e /run/systemd/system ] ; then
# exit 0
#fi

if [ -e /run/udev/hwclock-set ]; then
    exit 0
fi

if [ -f /etc/default/rcS ] ; then
    . /etc/default/rcS
fi

# These defaults are user-overridable in /etc/default/hwclock
BADYEAR=no
HWCLOCKACCESS=yes
HWCLOCKPARS=
HCTOSYS_DEVICE=rtc0
if [ -f /etc/default/hwclock ] ; then
    . /etc/default/hwclock
fi

if [ yes = "$BADYEAR" ] ; then
    /sbin/hwclock --rtc=$dev --systz --badyear
    /sbin/hwclock --rtc=$dev --hctosys --badyear
else
    /sbin/hwclock --rtc=$dev --systz
    /sbin/hwclock --rtc=$dev --hctosys
fi

# Note 'touch' may not be available in initramfs
> /run/udev/hwclock-set

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After i did this , its work on RTC time till someone reset or switch off the router. Upon router up, the raspberry pi picked up router time instead of RTC time. i have to do manually to switch to RTC time.

How i can over this, by saying just depend on RTC time only.
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3 Comments
Pi3 with Raspbian Stretch (fully update/upgraded) will not boot with enable_uart=1 in /boot/config.txt  -- bunch of stuff appears on the screen.
If I set it enable_uart=0, no problem.
My issue is that I need to use the UART Rx/Tx functionality.
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1 Comment
Brand new Raspberry Pi3 does not boot with Raspbian Jessie but will boot with Raspbian Stretch.  
All I get is the red light on the Pi -- not reading the microSD.
Reformatting and burning Stretch on the the same microSD card boots.
Is the Pi3 bad -- what is going on?
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3 Comments
I have ExaGear Desktop for Raspberry Pi 3 B+ and use WINE to successfully launch an x86 program.  The x86 program needs to communicate with a device using a USB-serial adapter.  So far I have not figured out how to get the x86 program to recognize the USB-serial adapter.

On a Windows laptop, we install USB Driver: CH341SER.exe and it just works without any troubleshooting or further configuration.  I tried but it wasn't as simple as installing the CH341SER driver software using WINE on the Pi.

The endgame is to create a portable "black box programmer" to change motor control settings on my Bafang powered eBike.

http://wiseinnovationtechnologies.com/programming-your-bafang-motor/
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7 Comments
I am trying to put this function in node-red. While testing on python its work on raspberry pi - serial port perfectly. Currently i wanted to try on node-red via raspberry pi too.

#rpi serial connections
#Python app to run a K-30 Sensor
import serial
import time
ser = serial.Serial("/dev/ttyS0",baudrate =9600,timeout = .5)
print " AN-137: Raspberry Pi3 to K-30 Via UART\n"
ser.flushInput()
time.sleep(1)
for i in range(1,21):

 ser.flushInput()
 ser.write("\xFE\x44\x00\x08\x02\x9F\x25")
 time.sleep(.5)
 resp = ser.read(7)
 high = ord(resp[3])
 low = ord(resp[4])
 co2 = (high*256) + low
 print "i = ",i, " CO2 = " +str(co2)
 time.sleep(.1)

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3 Comments
I installed dietpi today on a Zero w. (did it on a 3B+ and setup as Hotspot no problem). I wanted to setup the zero as a webcam.
I did this 4 times before I started to install or change the configuration and reboot at least 2 times to make sure all was good.
I changed the setup to US. connected to the Wi-Fi.
Updated to the latest version of dietpi. Update the firmware.
Changed drop bear to ssh.
installed REALVNC.
But when I Install RPI WEB CAM it keeps rebooting and I can't stop it.
As I said after the 3rd time I flashed a fresh image again and rebooted at least 2 times after each change or install until I got to the RPI Web CAM issue.
I get "You're in emergency mode. Enter root password for maintenance or CTRL D.
I tried dietpi for the password and root. CTRL D does nothing but reboot back to the same area.
I'm assuming there is am issue with RPI Web Cam.
And Yes I made sure the power supply is good. I replaced the power supply with one used on my Pi3B+. It's 5.2V, 3amps.
I even tested it with my voltmeter. The issue is this pi Zero W setup works fine with a full version of Raspian and the RPI WEB CAM version I had to manually configure. I switched back to that card and all is fine. I just like the small footprint and ease of setup with DietPi. And it only starts to reboot when I add in the Web Cam distro on DietPi. I even tried some other packages after my 4th attempt, on the card, flashed a new image. In fact I added a few distros to the DietPi setup …
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13 Comments
Hlw,

My self Abhinay Raj

I had made project on self driving car, In this project car will be move forward by follow the road lane using raspberry pi camera and some python program.

I want to develop this project by including fully automation in the self driving car. for this i have made one android application for booking cab(like uber). App. is working like such a way,that we will book cab same like as uber where app. will take the user current location and destination location. So, now i want to send the both (current,destination) location to the firebase database.And it will send to the raspberry pi than raspberry pi motor will move or follow the google map to arrive to the user first and than to the destination location.

Suppose that, if we have to go somewhere unknown place, here we use the google map, and it will provide me road on the map which is focus by blue line.. Means, i want to ask that similarly raspberry pi will also get loacation and it should follow the (blue line) the google map.

Please Help me....how can i do this...

thanks...
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1 Comment
Dear Experts,

I need to FTP from a Raspberry PI installation every 10 minutes a newly generated text file.

How do I do this automatically?
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3 Comments
Hi there,

I am try to learning a home automation system on Raspberry pi through GSM, but unfortunetally I am getting error in my python coding.
The Problem is When I want to print my received message that time I am getting this kind of response b'b\xf1\xe2\xe2\xe2' ,
So, I cant able to decode that message and If I decode that the python giving me a error like unorderable types: int() < str(().

So , I am really confused about it , can anybody help me out in this problem, How I can match my actual message and print?

here is my code and its output. 
import serial
import time
import os

print('Welcome to Test GSM SIM900')
ser = serial.Serial ("/dev/ttyS0", 19200, timeout=1) #9600 is the default for SIM900A modem
print('Waiting for Response')

ser.write(('AT+CMGF=1' + '\r').encode('utf-8'))
time.sleep(1)
print('Connection Establish')
ser.write(('AT+CMGDA="DEL ALL"'+'\r').encode('utf-8'))
time.sleep(1)
print('All messages has been Deleted')

message = ser.read(1000) # inWaiting- get the number of bytes in the inout buffer

print(message)

while True:
      if message == 'LED1':
          print ("LED 1 is on")
      elif message == 'LED2':
          print ("LED 2 is on")
      elif message == 'EXIT':
          print ("shuting down")
          ser.close ()
          break
      else:
          print ("Try again")
          break

ser.close() #close the serial port
  
>>> %Run GSMTRY.py
Welcome to Test GSM SIM900
Waiting for Response
Connection Establish
All

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…
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2 Comments
I posted this on raspberrypi.org on July 8,2018 and got 62 views but no replies. I was hoping someone would have some ideas why the pi is dead and maybe how to remove the heatsink/fan module.
I set up a Pi 3B+ as a router back in March 2018. I had same setup on a Pi3B that was running fine for 2 plus years with no issues and only heatsinks. Well I decided to switch the micro card to the 3B+ but of course it did not boot since the OS was not compatible.
So I flashed the newest of Raspbian , installed the code and changes for the router config and the new 3B+ was working fine. I didn't have any overheating issues but decided to put on the new dual fan system from Iuniker made for the 3B+.
This worked for I guess about 2 weeks and I went to upgrade my Pi's last week. (I have many small projects on Pi Zero, pi Zero W, Pi3B and this new Pi3B+) and could not SSH or VNC into the 3B+. So I checked on it and the only light that was on was the Red led and the fan was still running. No green activity light and the ethernet lights were not flashing.
 I found it strange the Pi was not running but the fan was. I unplugged the pi. Waited a minute and plugged the power back in. Only the Red led came on and the fan.
The green light didn't even flash once. So I tried everything. Unplugged the fan. A power supply (I uses 5V with 2.5 or 3 amps) I know is working from another Pi3B. I replaced the card with a fresh image of the OS. Still nothing. I have another Pi3B+. I took the card and …
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8 Comments
OK so I want to build a cell phone using a Raspberry Pi.
I'm not sure what module to get. Does anyone know. Some are advertised as GSM/GPRS and some as 4G/LTE.
I know GSM is the way to go but still confused when the description doesn't say they handle 4G/LTE.
And any suggestions on the best module to buy. Don't need blue tooth since the Pi already has that and has Wifi.
P.S. I usually buy my componets from Aliexpress.com. Slow delivery but cheaper price, good quality and selection.
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4 Comments
how rfid reader read uhf rfid tag using python language.........plz help mi
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1 Comment
how raspberry pi 3 model connect with UHF RFID Reader version ETS-IR O1 with using interface rs-232
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3 Comments
Hello Internet!

I have a few usb miners running on a raspberry pi.

this is what i'd like to achieve.

  1. automatically reboot pi every... say... 4 hours
[list=2]when pi starts up - start screen session and run cmd: sudo /home/pi/git/vthoang/cgminer/cgminer -o stratum+tcp://eu.stratum.slushpool.com:3333 -u zbw123.worker1 -p x --gekko-2pac-freq 150 [/list]

there are a few examples of this being done that i can find online but they all seem to assume a certain level of linux understanding and the truth is i know absolutely nothing about linux. i can follow instructions to the letter but thats about it! :-)

i have bought a book "for dummies" but i'm not finding the answers i need. If it were windows i'd wright a start.bat file i guess.

I downloaded a GUI for crontab which helps you manage scheduled tasks but of course it requires the appropriate files to exist already so that i may run....
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9 Comments
Is it possible to install HAProxy on a Raspberry Pi?

I would like to configure HAProxy as Reverse Proxy but would like to do this on a Raspberry Pi if possible.

Thanks
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3 Comments
Hi

I am doing a collage project where i need to host a home server   Using Nginx  and basically LAMP  with  wordpress.
I have managed to set my home router so it is able to send anything on the 80 port to the Raspberry PI    everything is perfect   apart from i need to try and get 443 SSL working.

I have installed CertBot and created all the keys

The website files are in /Var/www/html   (Wordpress site)

I have updated the Nginx  default file  located in /etc/nginx/sites-available/   which i am pretty sure is the issue.    I have a chron job set up for auto renewal of the SSL.   Everything seams to be set up perfectly   apart from the Nginx   config doesnt seam to be able to  serve SSL pages.       I really hate to ask but i have been trying for a few days now   cloning SD cards  to ensure i do it each time with the clean install  but  i cant work it out.    

/etc/nginx/sites-available/default

server {
    listen 80 default server;
listen [::]:80 default_server;

listen 443 ssl;
    root /var/www/html/;
    index index.php index.html index.htm;

    server_name My-Domain.com;
return 301 https://$server_name$request_uri;
ssl_certificate /etc/ssl/certs/dhparam.pem
ssl_certificate /etc/letsencrypt/live/my-domaincom/fullchain.pem;
        ssl_certificate_key /etc/letsencrypt/live/my-domain.com/privkey.pem;

    location / {
        try_files $uri $uri/ =404;
    }


  }
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17 Comments
I am running nginx on a raspberry pi.

I want to run it as a reverse proxy.

I have multiple servers running ssl and one needing forwarding on multiple ports (2195,2196,5228,5229,5230,38880,38881,80,443)

My question is two fold.

Is this even possible? in other words can you forward ports that are non http based ports. For example ports other than 80 8080 443 stuff like that.

I own a domain linked to a dynamic DNS service so I have *.mydomain.com available (* being anything I want it to be)
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5 Comments
I need to determine if a Raspberry Pi would be appropriate for a project I am developing. I am trying to create a game (non-commercial) that includes a soft, pillow-like object that will be thrown. I would like to insert a sensor that would detect changes in acceleration, and respond by playing a sound from an internal speaker. The internal apparatus must be self contained and battery operated. I have considered using a Raspberry Pi with a lithium ion battery pack, and an attached speaker and sensor (piezo disk?). When the "pillow" is thrown, the acceleration is detected and a sound is played. When that "pillow" lands, the deceleration is detected and a different sound is played.

Question: Do you think this can be done with a Raspberry Pi, and if so, do you think the Raspberry Pi and components could withstand the acceleration and deceleration associated with being thrown about?

Thanks.
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2 Comments
i change my raspberry pi IP address to static and it was working perfectly but after few days when i scan it via advance IP scanner it is showing dead but all the lights are coming.
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3 Comments
Where do I set the pi to point to a network time server?
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7 Comments
So I'm embarking on a new adventure, that of learning Python, and I'm trying to get some insights on...well, the questions I don't know enough to ask. So here's a list of what I'm trying to accomplish and perspectives/suggestions I'm hoping to gather from the EE community:

Your thoughts on:
  1. Embracing an incredibly loose language (I'm not used to that).
  2. Picking up learning techniques and perspectives which:
        a. Lend themselves to writing code for a broad variety of settings (ie. AI development, microcontroller coding (RPi, Arduino), robotics, IOT). I don't want find out later that I've wasted my time (eg. find out that I should have stuck with Python inside Visual Studio instead of going to the trouble of learning Pycharm -- or a similar kind of misstep).
  3. Biggest surprises and gotcha's coming from the .NET world to Python.  
  4. Anything else you can think of that I really need to know to make Python easier to pick up and make me the most versatile Python coder I can be.

By the way, I've not done any Raspberry Pi or Arduino coding yet (or AI stuff) yet. I'm a programmer by trade, just not in those areas.
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4 Comments
good day, I am testing serial port communciation on raspberry pi 3 interface with SIM 900 module. The code are attached with error message. Thanks

import serial
import os, time
 
# Enable Serial Communication
port = serial.Serial("/dev/ttyS0", baudrate=38400, timeout=1)
 
# Transmitting AT Commands to the Modem
# '\r\n' indicates the Enter key
 
port.write('AT'+'\r\n')
rcv = port.read(10)
print (rcv)

>>> 
======================== RESTART: /home/pi/SIM900.py ========================
Traceback (most recent call last):
  File "/home/pi/SIM900.py", line 1, in <module>
    import serial
  File "/home/pi/serial.py", line 5, in <module>
    port = serial.Serial("/dev/ttyS0", baudrate=38400, timeout=1)
AttributeError: module 'serial' has no attribute 'Serial'
>>>
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2 Comments
Hi, I am monitoring weather status remotely. I am intend to use Huawei E303F -usb dongle to push data. I did try sakis3g, doesn't help auto-connection after restart. please do assist me how to set internet connection automatically after restart and network down.
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5 Comments
Congratulations to our High-Tech Treats winners!

1st Place: Razi Riaz
Prize: PS4 Pro
2nd Place: Geri Hames
Prize: Echo Dot
3rd Place: Robert Coan
Prize: Raspberry Pi 3

Thank you to all who participated! Be on the lookout for future tech gadget giveaways.
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1 Comment
LVL 9

Expert Comment

by:Mark Bill
well done guys

well done EE
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Good day, I am newbie in python programming. Can get some information on treading (multi processing). I am doing project with raspberry pi 3 to monitor the following sensor: -
1. temperature
2.humidity
3. CO
At same time using 3g USB dongle to push data to cloud. My critical issue is 3g USB dongle, need to monitor that everytime.
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3 Comments

Raspberry Pi

159

Solutions

7

Content

i
The collection of articles, videos, and posts on this topic.

275

Contributors

The Raspberry Pi Foundation works to put the power of digital making into the hands of people all over the world, so they are capable of understanding and shaping our increasingly digital world, able to solve the problems that matter to them, and equipped for the jobs of the future.

We provide low-cost, high-performance computers that people use to learn, solve problems and have fun. We provide outreach and education to help more people access computing and digital making. We develop free resources to help people learn about computing and how to make things with computers, and train educators who can guide other people to learn.