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 specify if you want a Serial console (probably no) then if you want the Serial Port hardware enabled (probably yes). Then use /dev/serial0 in any code which accesses ...
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 terminal or desktop and shell Configure the system with:
Expand filesystem and enable serial on advanced page, exit and reboot.
Step 2 -this ...
The Gammu documentation suggests (but doesn't go into any detail of) a workaround,
Edit: Atmel has an Application Note that nicely describes the enumeration process.
Enumeration changes because it happens in a conversation between host, hub and device, and response timing from each of these may vary, even if the setup is identical from one reboot to the ...
I think you would call them P*-Headers, where the * designates which one exactly (5/2/3/6).
What you call Opportunity B is known as the P5-Header, and you can use it just like the GPIO-Pins next to it (see also this link).
Opportunity A (P6) can be used to reset your Raspberry Pi: Shorten it it reset. Be careful, though, as doing this while your SD-Card is ...
Ensure terminal over serial is disabled in raspi-config
and in "Advanced" choose "Serial" (Enable/Disable shell and kernel messages on the serial connection) and disable it.
Steps 2 and 3 should not be necessary if you do this step first, but in case it didn't work - check them also.
Ensure /boot/cmdline.txt has no ttyAMA0
The short answer to your question, how to safely connect the RPi to an Arduino, is indeed given at the first link you posted: http://blog.oscarliang.net/raspberry-pi-arduino-connected-i2c/. I have used the method given there with great success, and without damaging any components.
But your question suggests that you don't trust that method, and I think the ...
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 SD card on the fat32 partition):
Then plug it in, and the pi will directly print stuff on the console pins.
@Milliways had the best answer in my opinion. His answer can be found here: Link given here
ttyAMA0 can be the Tx, Rx pins for the Raspberry. But for the Raspberry Pi 3b it was used for the Bluetooth. Because of this, pins 8 & 10 were using the miniUART which is labeled ttyS0 (unless you disable the Bluetooth which has instructions in that link in the ...
@LiWi's answer will work temporarily, but the permission change will be lost once the device is removed or the server rebooted.
A permanent solution is to add your user to the dialout group, which will allow it to access serial devices.
sudo usermod -a -G dialout youruser
The properties of a USB serial converter have nothing to do with the hardware of the hosting system, but only with the USB serial chip itself, and the software stack of the hosting system.
The pi should be using stock Linux USB serial drivers.
Therefore, you can enable/disable the linkage of DTR to port open/close via the usual Linux method of clearing the ...
First uninstall serial with sudo pip uninstall serial (thank you so much Ali!)
Then, if import serial does not work anymore: use sudo pip install pyserial. This will install the correct serial module for the RP.
You've partially answered your own question, but there is another way of doing it, especially for serial devices: the /dev/serial/* paths. I have a Prolific USB→RS232 interface on my Raspberry Pi which almost invariably shows up as /dev/ttyUSB0. But it also appears on the system as:
For basic network communication nc or netcat, as suggested by joan, is sufficient. However, if you for example want to forward a serial console or encrypt the connection socat is probably more convenient. For inspiration here are two working examples of the mentioned applications.
Serial console via TCP
To connect directly to the serial port with socat ...
The Pi's UART has a fault (in the firmware). Whenever the port is opened there is a 30 µs low glitch on TXD.
See http://elinux.org/RPi_Serial_Connection#Unwanted_serial_garbage_input and search for glitch.
You will need to find a workaround as the fault will not be fixed.
From man 5 crontab:
Step values can be used in conjunction with ranges. Following a range with "/<number>" specifies skips of the number's value through the
range. For example, "0-23/2" can be used in the 'hours' field to specify command execution for every other hour (the alternative in the V7
standard is "0,2,4,6,8,10,12,14,16,...
Raspberry Pi4 UART
The Pi4 has 4 additional UART (uart2-uart5) in addition to uart0/1 on the older Pi (only one of which can be used as they share GPIO).
Functionally these are equivalent to the fully featured PL011 UART on uart0 and can optionally be configured with CTS/RTS.
See UART configuration for Foundation documentation.
These can be enabled (by ...
cat /proc/cpuinfo | grep Revision
RPi 2 boards will show board revisions a*1040, a*1041 or a*2042, while an RPi 3 board will give you a*2082. Here's a list of board revisions.
See also: Getting Your Raspberry Pi Revision Number Using Python.
Given the significant differences in the voltage levels it is not safe to directly connect any RS232 signal lines to the Pi's GPIO. Even if the voltage of some RS232 drivers might be as low as 3 V, the logic one (called "mark") is represented as a negative voltage which will kill the Pi.
The standard specifies a maximum open-circuit ...
The Pi has 2 serial ports, but only 1 is accessible - the other is connected to Bluetooth. (It is possible to switch ports in Device Tree.)
See How do I make serial work on the Raspberry Pi3 , Pi3B+, PiZeroW for more detail.
You can add additional ports with a USB-serial adapter.
If you don't want to spare your USB port of your Rpi, you can use GPIO Serial to communicate with your Arduino. There is a great tutorial of Conor O'Neill for connecting Rpi with a Arduino Pro Mini. The procedure is the same with your Arduino Uno.
All you need is a LLC (Logic Level Converter) to be able to connect these two devices. As you've already ...
What you are referring to is called Software Serial, where bytes are bit banged and create the same effect as a serial port.
Using a normal Linux distribution the answer is, No. The reason is because bit banging required real time processing of data, otherwise the data will just be junk.
This answer at Electronics Stack shows a USB board with 4 hardware ...
Wand has a display module/method.
In the terminal
$ python -m wand.display wandtests/assets/mona-lisa.jpg
In a Python script
with Image(blob=file_data) as image:
The default bash prompt is set in a system wide file; for a complete explanation of how bash sources its configuration see INVOCATION near the top of man bash. In short, that system wide file is sourced by ~/.bashrc; it is pretty obvious.
# Source global definitions
if [ -f /etc/bashrc ]; then
Evidentally, what's deciding about ...
Any answer might only be of limited help to you as long as you have not understood how SPI actually works, so you should take a detailed look at this interface.
Concerning question 1:
SPI is a master-slave-system where any interaction has to be initiated by the master. The sensor itself is not able to write to the master, instead it is read by the master (...
@ChrisStrattons post describes how to use stty -F /dev/ttyUSB0 to avoid the hangup which results in a reset. Here is a snippet to do it in Python:
path = '/dev/ttyACM0'
# Disable reset after hangup
with open(path) as f:
attrs = termios.tcgetattr(f)
attrs = attrs & ~termios.HUPCL
termios.tcsetattr(f, termios.TCSAFLUSH, ...
If you're using an X11 Desktop Environment such as LXDE, then you can accomplish this using the basic logic shown in this article.
Here's what I came up with to switch displaying two images waiting 30 seconds between each switch. You should be able to insert your logic for switching the images based on what you read from your RFID sensor.
You should not re-create the object Serial at each iteration of the loop. I suppose that the line serialport = serial.Serial("/dev/ttyAMA0", 9600, timeout=0.5) closes and re-opens the serial port, flushing all the buffers.
Try this :
serialport = serial.Serial("/dev/ttyAMA0", 9600, timeout=0.5)
command = serialport.read(...
This is probably the well known bug of the spurious character when the serial port is opened. I don't remember the details, something to do with the TX line dropping for an instant so signalling a spurious start bit. From memory it is a bug in the Raspberry Pi Linux driver. I don't know why it hasn't been fixed, it has been commented on for several years.