I am trying to establish a communication b/w raspberrypi(Raspbian) and PC(Microsoft XP) through GPIO PINS 14(Tx) and 15(Rx) for sending/receiving data... , RS-232 level converter is using for connection of GPIO to PC serial COM port and Voltage conversion from 3.3V to 12V...
I install minicom (Echo ON) at raspberry side and install Teraterm(ECHO OFF) at PC side.
Whatever I typed on minicom, it successfully appear on Minicom and Teraterm but when I tried same thing on Teraterm, it only appears on Teraterm not on minicom and also blocked by minicom (/dev/ttyAMA0). After that I am not able to send data from minicom to Teraterm.
But I just check one thing more and very surprise that, when shorting GPIO PIN 14& 15 together and starting typing on minicom... it just show me one character and stop after that...
Again I repeat whole process by closing/opening minicom, again it just show character and then stop.
Can you plz guide me why it happening and how do I resolve it?
I just read from this link that someone was also facing your kind of problem but not exactly what you are facing.
It is happened because Kernel takeover the control on console so It is good and very important to disconnect the connect of console and kernal from the startup.
Now you can follow these step, I am sure you will get rid from this trouble...
Start editing this file by this command
sudo vi /boot/cmdline.txt
Originally it contained:
dwc_otg.lpm_enable=0 rpitestmode=1 console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 rootwait
deleted the two parameters involving the serial port (ttyAMA0) to get the following:
dwc_otg.lpm_enable=0 rpitestmode=1 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 rootwait
rebooted (sudo reboot) to confirm that kernel output was no longer going to the serial port. But the serial console was still available. So edited /etc/inittab:
sudo vi /etc/inittab
commented out the following line:
2:23:respawn:/sbin/getty -L ttyAMA0 9600 vt100
Finally, rebooted again and confirmed that nothing was touching the serial port anymore. Then, to test it out installed minicom on the Raspberry Pi:
sudo apt-get install minicom
And ran it:
minicom -b 9600 -o -D /dev/ttyAMA0
After, it is able to send data in both directions!
Related
I have Raspberry Pi Zero W and this hat.
I did the following things:
disabled login shell through serial in rasp-config
enabled serial port hardware in rasp-config
removed console=serial0 in /boot/cmdline.txt
added lines to /boot/config.txt:
enable_uart=1
dtoverlay=pi-miniuart-bt
Then I restart the RPI.
Problem...
But when I do sudo minicom -D /dev/serial0 (serial1, ttyS0, and ttyAMA0 doesnt work either), it says its offline...
Am I missing something?
Here are all the files that might be interesting:
cmdline.txt
config.txt
To switch the bluetooth controller to the mini-UART so you can use the PL011 UART to communicate with your HAT, you should specify
dtoverlay=miniuart-bt
Alternatively you can use
dtoverlay=pi3-miniuart-bt
which was kept around for backwards compatibility.
EDIT: This problem is solved! the problem was a script running on the pi, which occupied the SCL pin (in my case a script listening for a shutdown button). So it was not able to read the rtc.
I'm currently following this tutorial to connect my Raspberry Pi Zero W running Jessie Lite to the RTC DS1307.
The rtc is being recognized when running sudo i2cdetect -y 1 with "UU", so everything fine until this point.
But when entering sudo hwclock -D -r I'm getting an error:
Does anybody have any experience or hints with this error? I was researching for 1 1/2 day now, but could not find a working solution. Any help is appreciated.
Back then I was not able to answer my own question. I have already edited the main post, but to close this question:
This problem is solved! the problem was a script running on the pi, which occupied the SCL pin (in my case a script listening for a shutdown button). So it was not able to read the rtc.
I'm trying to set up a FONA 808 to connect to the internet to a Raspberry Pi 3, but when I run the serial console "sudo screen / dev / serial0 115200" I'm sometimes answered with "OK" and in others the console displays the message as if it were electromagnetic noise, and at other times the console simply crashes Is this normal? How can I solve that?
I am using a Fona 808 Arduino Shield connected to 5V and the TX and RX ports pass through a level logic shifter to convert the logic of 5V of the fona to logic of 3.3V of the raspberry
I am following this tutorial:
https://learn.adafruit.com/fona-tethering-to-raspberry-pi-or-beaglebone-black/setup
Blocked console:
Electric noise display:
Check your /boot/cmdline.txt file.
This is how I solve my pi with the same error.
nano /boot/cmdline.txt or sudo nano /boot/cmdline.txt
copy the script below and paste this in your cmdline.txt
dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait
make sure "console=ttyAMA0,115200" is not on the script.
Make sure you have your original script. Test your pi if it reboot correctly. If it doesn't you can change back the cmdline.txt directly on your sd card and paste your original script.
This command should work with the response back
sudo screen /dev/serial0 115200
AT
ok
This should be a comment but I don't have the reputation to comment so...
Couple of things to try that might help.
1) You shouldn't need the level logic shifter. I don't know exactly what FOAN board you are using but they normally have a Vio pin that sets the voltage of the logic. So in this case you just connect the Vio pin to 3.3V on the Raspberry Pi and the RX and TX will be working at 3.3V.
2) Check your wire connections. Might just be a case of a bad connection.
3) I had better luck with minicom than screen So a command like this should work to connect the bard. sudo minicom -b 115200 -o -D /dev/ttyS0
I am trying to configure LIRC to work with my Raspberry 2B and a circuit I build with a transistor and a IR transmitter as explained in this tutorial
After the installation of LIRC, I followed all the steps and I added these two lines in /etc/modules
lirc_dev
lirc_rpi gpio_out_pin=36
Then I typed this in /etc/lirc/hardware.conf
LIRCD_ARGS="--uinput"
LOAD_MODULES=true
DRIVER="default"
DEVICE="/dev/lirc0"
MODULES="lirc_rpi"
LIRCD_CONF=""
LIRCMD_CONF=""
After rebooting, I added the configuration of my Samsung remote (BN59-00516A) to /etc/lirc/lircd.conf
Then I restarted LIRC again but when I run a command to send a IR frequency
irsend SEND_ONCE Samsung_BN59-00865A KEY_POWER
it complains with the following error:
irsend: could not connect to socket
irsend: No such file or directory
I am guessing this is a problem with my device socket, because in the hardware.conf file I set
DEVICE = "/dev/lirc0"
(just because the tutorial states it), but lirc0 file isn't within the folder.
I couldn't find any other question related to this problem and google didn't help me much either. Does anyone have any hint on this?
After googling a lot, I found out an update is needed to have everything working properly. In my case I did:
apt-get update, apt-get upgrade, rpi-update
Also, as pointed out in this other tutorial, depending on the Raspberry firmware, you might need to add this to /boot/config.txt
dtoverlay=lirc-rpi,gpio_in_pin=XX,gpio_out_pin=YY
Substitute X and Y for whatever pins you're using!
I had a similar problem and I solved it with this command:
sudo lircd --device /dev/lirc0
If you set the value of LIRCD_ARGS in /etc/lirc/hardware.conf to "--device /dev/lirc0", it should start lircd appropriately, when /etc/init.d/lirc is started at boot.
you need to run lircd. It will create two files (lircd and lircd.pid) at /var/run/lirc/:
lircd
I got the same error messages. But had all configurations done. The restart of the lirc daemon solved this issue by typing
$ sudo /etc/init.d/lirc restart
I think is useful to say that the gpio_in_pin=XX,gpio_out_pin=YY part of the /etc/modules can be double checked with
dmesg | grep lirc
which results in something like
[ 3.437499] lirc_dev: IR Remote Control driver registered, major 244
[ 5.472916] lirc_rpi: module is from the staging directory, the quality is unknown, you have been warned.
[ 6.621156] lirc_rpi: auto-detected active high receiver on GPIO pin 22
[ 6.622515] lirc_rpi lirc_rpi: lirc_dev: driver lirc_rpi registered at minor = 0
[ 6.622528] lirc_rpi: driver registered!
for /etc/modules containing
lirc_dev
lirc_rpi gpio_in_pin=23 gpio_out_pin=22
I bought a Raspberry Pi 3 Model B, a microstack baseboard and a microstack GPS.
I followed the instructions written in the official documentation but I can't connect to the GPS.
Basically, the GPS led flashes so it means it has find a gps fix, but I can't see any data from the PI.
For example, if I try
cat /dev/ttyAMA0
I get always nothing. I already used raspi-config to disable kernel serial and to enable i2c and spi.
Also if I try
stty -F /dev/ttyAMA0 ispeed 4800 && cat </dev/ttyAMA0"
I get an error.
Anyone has any advice, please?
Or maybe these modules are not compatible with Pi 3?
Thanks a lot!
It's hard telling what has been done, or not done. The 'official' documentation from Microstack provides two methods of setting up the serial port. It then continues with
Automatically Starting gpsd
To automatically start the gps service when the Raspberry Pi® boots, reconfigure the GPS
daemon by typing into a terminal
sudo dpkg-reconfigure gpsd
● Choose <yes> when asked if you want to start gpsd automatically.
● Choose <no> when asked “should gpsd handle attached USB GPS
receivers automatically” .
● When asked which “Device the GPS receiver is attached to” , enter
/dev/ttyAMA0 .
● Accept the defaults for other options.
If you have configured your serial port as per instructions and configured gpsd to automagically start and pick up the device you have just setup, ...then, since the gpsd is handling the device (right?), the device will be busy and the command cat /dev/ttyAMA0 should return cat: /dev/ttyAMA0: Device or resource busy...but, it did not.
Either the serial is not configured as per instructions, or the gpsd is not running and picking up the device, or both.
The goal is not to cat your gps data, but the cat not returning an error indicates something is amiss.
Typically, it's just a typo. But it can be from skipping a step in the process, or mixing instructions from various sources so that the left hand doesn't know what the right hand has done.
Try:
sudo killall gpsd if it returns gpsd: no process found that answers one question.
If it returns with no error, follow it up with cat /dev/ttyAMA0. If it returns nothing, the direction you should look is your serial port configuration.
If sudo dpkg-reconfigure gpsd is not allowing you to reconfigure (I thought it was just me) you can modify the configuration of gpsd by using your favourite editor, e.g. sudo nano /etc/default/gpsd and entering something like:
# Default settings for the gpsd init script and the hotplug wrapper.
# Start the gpsd daemon automatically at boot time
START_DAEMON="true"
# Use USB hotplugging to add new USB devices automatically to the daemon
USBAUTO="false"
# Devices gpsd should collect to at boot time.
# They need to be read/writeable, either by user gpsd or the group dialout.
DEVICES="/dev/ttyAMA0"
# Other options you want to pass to gpsd
GPSD_OPTIONS="-n -G"
You may find the -n and -G useful. Save and restart.
I finally found a solution:
On the Pi 3, there are more steps to use serial, you have to disable the BT.
Edit config file:
sudo nano /boot/config.txt
Add this at the bottom:
dtoverlay=pi3-disable-bt-overlay
Then run this:
sudo systemctl disable hciuart
This article was very usefull for me
http://spellfoundry.com/2016/05/29/configuring-gpio-serial-port-raspbian-jessie-including-pi-3/#comment-67160
and i recommand you to read it
Now on RPI3 the Serial port
ttyAMA0 is used by BlueTooth
ttySO refers to the GPIO
The Alias Serial0 refers to the GPIO both on RPI2 and RPI3.
So :
after a reinstallation of Jessie with a recent version to be sure all is clean
as usual
$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo raspi-config
go to Advanced options : Would you like a login shell to be accessible over serial? response "yes" (not as in the microstack datasheet )
$ sudo apt-get install python3-microstacknode
To install the gpsd standard tools
$ sudo apt-get install gpsd gpsd-clients python-gps
edit GPSD by
$ sudo nano /etc/default/gpsd
and put the options :
START_DAEMON="true"
USBAUTO="false"
DEVICES="/dev/serial0"
GPSD_OPTIONS="-n -G"
equally
$ sudo nano /boot/cmdline.txt
remove
console=serial0,115200
and save
$ sudo nano /boot/config.txt
you must have at the end
enable_uart=1
Disable the console by
$ sudo systemctl stop serial-getty#ttyS0.service
$ sudo systemctl disable serial-getty#ttyS0.service
i have equally done $ sudo chmod 775 ../../dev/ttySO ( i dont know if it is really necessary )
and obviously a reboot
and miracle the gps works with
cgps -s
NB: you must have a fix on the GPS ( the red led flashes )
jpherrenknecht