I believe this is an off-by-one-error:

https://github.com/adafruit/Adafruit_Python_CharLCD/blob/master/Adafruit_CharLCD/Adafruit_CharLCD.py#L177

Should be >= otherwise we can address rows 0, 1, or 2 on a 2 line display.

Hi,

here is my problem:
Raspberry Pi with Raspbian operating system

get the following error
lcd = LCD.Adafruit_CharLCD(lcd_rs, lcd_en, lcd_d4, lcd_d5, lcd_d6, lcd_d7, lcd_columns, lcd_rows, lcd_backlight)
File "build/bdist.linux-armv7l/egg/Adafruit_CharLCD/Adafruit_CharLCD.py", line 143, in init
File "build/bdist.linux-armv7l/egg/Adafruit_GPIO/GPIO.py", line 278, in setup
TypeError: argument 1 must be string, not int

i've defined the variables:
#LCD variables
lcd_rs= 18
lcd_en= 23
lcd_d4= 12
lcd_d5= 16
lcd_d6= 20
lcd_d7= 21
lcd_backlight= 4
lcd_columns= 16
lcd_rows= 2

and included the library
import Adafruit_CharLCD as LCD

Thank you for opening an issue on an Adafruit Python library repository. To
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  something isn't working as expected. In many cases the problem is a common issue
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  are meant for known defects in the code. If you don't know if there is a defect
  in the code then start with troubleshooting on the forum first.

• If following a tutorial or guide be sure you didn't miss a step. Carefully
  check all of the steps and commands to run have been followed. Consult the
  forum if you're unsure or have questions about steps in a guide/tutorial.

• For Python/Raspberry Pi projects check these very common issues to ensure they don't apply:

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    missing library can be installed with the pip tool, but check the tutorial/guide
    for the exact command.

  • Be sure you are supplying adequate power to the board. Check the specs of
    your board and power in an external power supply. In many cases just
    plugging a board into your computer is not enough to power it and other
    peripherals.

  • Double check all soldering joints and connections. Flakey connections
    cause many mysterious problems. See the guide to excellent soldering for examples of good solder joints.

If you're sure this issue is a defect in the code and checked the steps above
please fill in the following fields to provide enough troubleshooting information.
You may delete the guideline and text above to just leave the following details:

• Platform/operating system (i.e. Raspberry Pi with Raspbian operating system,
  Windows 32-bit, Windows 64-bit, Mac OSX 64-bit, etc.): INSERT PLATFORM/OPERATING
  SYSTEM HERE

• Python version (run python -version or python3 -version): INSERT PYTHON
  VERSION HERE

• Error message you are receiving, including any Python exception traces: INSERT
  ERROR MESAGE/EXCEPTION TRACES HERE*

• List the steps to reproduce the problem below (if possible attach code or commands
  to run): LIST REPRO STEPS BELOW

error: Download error for https://github.com/adafruit/Adafruit_Python_GPIO/tarball/master#egg=Adafruit-GPIO-0.4.0: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:661)

Hello! Please, help me with a some question. I need to disable cursor moving when using function
lcd.message(). If I use lcd.set_cursor() and after this use lcd.message(), cursor changes his position.
How I can disable this effect?

Hey, I'm coming here from this product page http://www.adafruit.com/products/1115

Then to https://learn.adafruit.com/character-lcd-with-raspberry-pi-or-beaglebone-black/usage

And finally I'm here. So this uses Python. I'm going to add this to a ruby project, so I feel like I should use the ruby equivalent to this library to minimize the number of languages involved. It seems as though the ruby equivalent doesn't exist yet though. Correct me if I'm wrong, but to get the ruby equivelent I'd more or less just need to do a lot of copy and pasting (and do minor syntax editing) from this repo and also this Adafruit_Python_GPIO library https://github.com/adafruit/Adafruit_Python_GPIO and then call it a day, right? It seems odd that I would be the first to do that, so maybe I'm missing something?? If any repo watchers know of other libraries involved in the i2c chip used in the LCD that I should know about, I'd love to hear about it, and maybe the extra link/info should go into one of the repos so others know.

When using the message-method repeatedly, only the second line of the LCD is updated.
An example script for reproducing the issue can be found here: https://gist.github.com/JanBe/8f8390484c13b7ab42a7

When executing the script, it would be expected to find the following output on the LCD:

New first line
New second line

However, the LCD reads:

First line
New second linef

As stated above, the first line is not updated. Additionally, the second line contains fragments from the sentence that was supposed to end up in the first line. The sentence was written to the end of the second line and then again overwritten by the updated second line:
Second line => Second lineNew f => New second linef

A workaround is to call clear() before subsequent uses of message, which however results in a small period of time between the two messages, in which the display is empty (and therefore looks like its flickering).

Thank you for opening an issue on an Adafruit Python library repository. To
improve the speed of resolution please review the following guidelines and
common troubleshooting steps below before creating the issue:

• Do not use GitHub issues for troubleshooting projects and issues. Instead use
  the forums at http://forums.adafruit.com to ask questions and troubleshoot why
  something isn't working as expected. In many cases the problem is a common issue
  that you will more quickly receive help from the forum community. GitHub issues
  are meant for known defects in the code. If you don't know if there is a defect
  in the code then start with troubleshooting on the forum first.

• If following a tutorial or guide be sure you didn't miss a step. Carefully
  check all of the steps and commands to run have been followed. Consult the
  forum if you're unsure or have questions about steps in a guide/tutorial.

• For Python/Raspberry Pi projects check these very common issues to ensure they don't apply:

  • If you are receiving an ImportError: No module named... error then a
    library the code depends on is not installed. Check the tutorial/guide or
    README to ensure you have installed the necessary libraries. Usually the
    missing library can be installed with the pip tool, but check the tutorial/guide
    for the exact command.

  • Be sure you are supplying adequate power to the board. Check the specs of
    your board and power in an external power supply. In many cases just
    plugging a board into your computer is not enough to power it and other
    peripherals.

  • Double check all soldering joints and connections. Flakey connections
    cause many mysterious problems. See the guide to excellent soldering for examples of good solder joints.

If you're sure this issue is a defect in the code and checked the steps above
please fill in the following fields to provide enough troubleshooting information.
You may delete the guideline and text above to just leave the following details:

• Platform/operating system (i.e. Raspberry Pi with Raspbian operating system,
  Windows 32-bit, Windows 64-bit, Mac OSX 64-bit, etc.): INSERT PLATFORM/OPERATING
  SYSTEM HERE

• Python version (run python -version or python3 -version): INSERT PYTHON
  VERSION HERE

• Error message you are receiving, including any Python exception traces: INSERT
  ERROR MESAGE/EXCEPTION TRACES HERE*

• List the steps to reproduce the problem below (if possible attach code or commands
  to run): LIST REPRO STEPS BELOW

Hey,

is it possible to rotate the display view?

Thanks

Currently there seems to be a number of checks (and maybe other assumptions?) that require any program using this library to run as "root" user. This is extremely dangerous, especially if accepting user-input as it provides easy ways for an attacker to gain complete control over the operating system, possibly using it as an entry point to attack other devices and systems on the same network.

The library should instead allow you to make the calls as a non-root user and only generate an error message (or throw an exception which can be handled by the main application) if it encounters a problem. It is possible to configure permissions such that a non-root user has access to GPIO control and then the library would be able to run as that limited user safely confined to only the permissions the program requires.

In this example, you can see that my GPIO interface can be controlled by any user in the "gpio" group. This allows my various applications to run as unprivelaged users and the Linux kernel to enforce protections against potentially malicious activity (e.g. access user's personal files or change passwords) while still keeping full control of the GPIO interface to manipulate connected devices based on user-inputs.

$ ls -l /sys/class/gpio/
total 0
-rwxrwx--- 1 root gpio 4096 May 17 20:35 export
lrwxrwxrwx 1 root gpio 0 May 17 20:35 gpio12 -> ../../devices/platform/soc/3f200000.gpio/gpio/gpio12
lrwxrwxrwx 1 root gpio 0 May 15 21:09 gpio17 -> ../../devices/platform/soc/3f200000.gpio/gpio/gpio17
lrwxrwxrwx 1 root gpio 0 May 15 21:09 gpio18 -> ../../devices/platform/soc/3f200000.gpio/gpio/gpio18
lrwxrwxrwx 1 root gpio 0 May 15 21:09 gpio27 -> ../../devices/platform/soc/3f200000.gpio/gpio/gpio27
lrwxrwxrwx 1 root gpio 0 May 15 21:09 gpio4 -> ../../devices/platform/soc/3f200000.gpio/gpio/gpio4
lrwxrwxrwx 1 root gpio 0 May 17 20:35 gpio6 -> ../../devices/platform/soc/3f200000.gpio/gpio/gpio6
lrwxrwxrwx 1 root gpio 0 Dec 31 1969 gpiochip0 -> ../../devices/platform/soc/3f200000.gpio/gpio/gpiochip0
-rwxrwx--- 1 root gpio 4096 May 17 20:35 unexport

It may be if all the "is this root" checks are removed it would just work but I have not been successful in locating all the checks and understanding how the code works to fix this.
To check what groups a user is in you can use groups <username> and it will print the list of groups.
To add a user to the GPIO group, you can use the command sudo adduser <user> <group> where in raspbian would typically be "gpio" as shown in my directory listing.

BB Green running Debian 8.4 Jessie
Python 3.4

I have a simple test program running that displays text on an RGB screen
it works fine on the same hardware running Debian 7.8 Wheezy

But after upgrading to Jessie, I cannot get any text on the screen and there are no errors in non PWM mode.
In PWM mode I do get an error in Adafruit GPIO "must start the PWM channel first"

Is this library supposed to work in Jessie which has some changes in Capemgr etc?

Bill

Tried an example code to display on a 16x2 LCD with a BBB butt got the following error;
root@beaglebone:/Project/PythonEyeDetection# nano lcd_display.py
root@beaglebone:/Project/PythonEyeDetection# nano lcd_display.py
root@beaglebone:~/Project/PythonEyeDetection# python lcd_display.py
Traceback (most recent call last):
File "lcd_display.py", line 5, in
import Adafruit_CharLCD as LCD
ImportError: No module named Adafruit_CharLCD

I then triedfollowing instructions to install it by pip but got the following result. It looks like BBB comes with preinstall Adafruit library but the older version which when i try to use pip it does not upgrade.

root@beaglebone:~/Project/PythonEyeDetection# pip install Adafruit_BBIO
Requirement already satisfied (use --upgrade to upgrade): Adafruit-BBIO in /usr/local/lib/python2.7/dist-packages
Cleaning up...

Wwhen i try to upgrade i get the following result but without it working;
root@beaglebone:/usr/local/lib/python2.7/dist-packages# pip install Adafruit_BBIO --upgrade
Requirement already up-to-date: Adafruit-BBIO in /usr/local/lib/python2.7/dist-packages
Cleaning up...

Hi,

Is there a reason why the create_char function definition belongs to class Adafruit_RGBCharLCD instead of its parent Adafruit_CharLCD?

It doesnt seem to be RGB specific but a key feature of HD44780

Just bought this product: http://www.adafruit.com/product/1110
It works like a charm but something is bugging me..
Right now it seems that the only possible way to detect button presses is by using is_pressed() on a busy waiting loop. Needless to say this is highly inefficient.
This request involves 2 projects (this one and Adafruit_GPIO). I've looked into both the code of this project and of Adafruit_GPIO, and it seems that the use of GPIO.RPiGPIOAdapter in the MCP (instead of GPIO.BaseGPIO) would be more appropriate in the case of using a RPi, because it supports the events features not included in the current code.

I've tried to do this myself but I don't quite understand the code in Adafruit_GPIO/MCP230xx.py since it's my first time playing around the gpio. I'm not quite sure if it's a valid request or if I should submit it on the Adafruit_GPIO project instead.

It seems that the delay for the clear functionality across CharLCDs is a tad bit too quick for at least one such device. Clearing the screen and immediately sending a message gives garbage on the screen (using an adafruit bought 16x2 character LCD display). This was resolved by increasing the delay time between the clear() and message() calls.

Please also reference this stack overflow thread and notice the comments. This seems like a delay-time issue even after user switched to this repo's version of the lib.

• Platform/operating system (i.e. Raspberry Pi with Raspbian operating system,
  Windows 32-bit, Windows 64-bit, Mac OSX 64-bit, etc.): Raspberry Pi with Raspbian operating system

• Python version (run python -version or python3 -version): python 2.7

• Error message you are receiving, including any Python exception traces: N/A

• List the steps to reproduce the problem below (if possible attach code or commands
  to run): LIST REPRO STEPS BELOW

1. Initialize Adafruit_CharLCD
2. Perform display clear
3. Immediately after send a message using the message class function (e.g. lcd.message("string"))

In the example "sudo python char_lcd_plate.py". Almost everything seems like it works ok, but during the button press example, if I press the up or down button the backlight turns off. It correctly shows the button I pressed but without the backlight. Then if I press any other button, then backlight then turns back on. Any suggestions as to what may be causing this ?

Hey, I was trying to play around with LCD and installed this library. But when i write the command below in thonny and run it, it gives me this error;
ImportError: No module named 'Adafruit_CharLCD'

import time
import Adafruit_CharLCD as LCD

lcd_rs = 37
lcd_en = 35
lcd_d4 = 33
lcd_d5 = 31
lcd_d6 = 29
lcd_d7 = 23
lcd_backlight = 4

lcd_columns = 16
lcd_rows = 2

lcd = LCD.Adafruit_CharLCD(lcd_rs, lcd_en, lcd_d4, lcd_d5, lcd_d6, lcd_d7, lcd_columns, lcd_rows, lcd_backlight)

lcd.message('Hello\nworld!')
time.sleep(5.0)
lcd.clear()
text = raw_input("Type Something to be displayed: ")
lcd.message(text)

time.sleep(5.0)
lcd.clear()
lcd.message('Goodbye\nWorld!')

time.sleep(5.0)
lcd.clear()

i'm using python3
With Correct indentation.
Any help is greatly appreciated! Thank You

My screen doesn't show test, when i run the code it just turn the background light ON - GPIO 4- I'm not sure if something with the wires or the LCD itself is bad? is there is a way to test what's wrong?

Thanks
http://content.screencast.com/users/minagabriel/folders/Snagit/media/83d6748b-7219-4cfb-b3e7-f53c8f905112/2016-05-17_10-59-05.png

Add 'arch-armv61' as a Raspberry Pi platform in Platform.py.

Thank you for opening an issue on an Adafruit Python library repository. To
improve the speed of resolution please review the following guidelines and
common troubleshooting steps below before creating the issue:

• Do not use GitHub issues for troubleshooting projects and issues. Instead use
  the forums at http://forums.adafruit.com to ask questions and troubleshoot why
  something isn't working as expected. In many cases the problem is a common issue
  that you will more quickly receive help from the forum community. GitHub issues
  are meant for known defects in the code. If you don't know if there is a defect
  in the code then start with troubleshooting on the forum first.
• If following a tutorial or guide be sure you didn't miss a step. Carefully
  check all of the steps and commands to run have been followed. Consult the
  forum if you're unsure or have questions about steps in a guide/tutorial.
• For Python/Raspberry Pi projects check these very common issues to ensure they don't apply:
  • If you are receiving an ImportError: No module named... error then a
    library the code depends on is not installed. Check the tutorial/guide or
    README to ensure you have installed the necessary libraries. Usually the
    missing library can be installed with the pip tool, but check the tutorial/guide
    for the exact command.
  • Be sure you are supplying adequate power to the board. Check the specs of
    your board and power in an external power supply. In many cases just
    plugging a board into your computer is not enough to power it and other
    peripherals.
  • Double check all soldering joints and connections. Flakey connections
    cause many mysterious problems. See the guide to excellent soldering for examples of good solder joints.

If you're sure this issue is a defect in the code and checked the steps above
please fill in the following fields to provide enough troubleshooting information.
You may delete the guideline and text above to just leave the following details:

• Platform/operating system (i.e. Raspberry Pi with Raspbian operating system,
  Windows 32-bit, Windows 64-bit, Mac OSX 64-bit, etc.): INSERT PLATFORM/OPERATING
  SYSTEM HERE
• Python version (run python -version or python3 -version): INSERT PYTHON
  VERSION HERE
• Error message you are receiving, including any Python exception traces: INSERT
  ERROR MESAGE/EXCEPTION TRACES HERE*
• List the steps to reproduce the problem below (if possible attach code or commands
  to run): LIST REPRO STEPS BELOW

I'm using Raspberry pi B+ model and Adafruit 16x2 character LCD plus keypad for raspberry pi
I made all the steps in the guidelines when I write the final step sudo python cahr_lcd_plat.py the terminal gives me this error:

Traceback (most recent call last): File "char_lcd_plate.py", line 9, in lcd = LCD.Adafruit_charLCDPlate() File "build/bdist.linux-armv6l/egg/Adafruit_CharLCD/Adafruit_CharLCD.py", line 432, in init File "build/bdist.linux-armv6l/egg/Adafruit_GPIO/MCP230xx.py", line 150, in init File "build/bdist.linux-armv6l/egg/Adafruit_GPIO/MCP230xx.py", line 46, in init File "build/bdist.linux-armv6l/egg/Adafruit_GPIO/MCP230xx.py", line 130, in write_iodir File "build/bdist.linux-armv6l/egg/Adafruit_GPIO/I2C.py", line 95, in writelist IOError: [Errno 5] Input/output error

anyone can help me please? I2C operates on smbus[1]

Thanks

I really like the library you made here but these 2 functions aren't working and I'm wondering if there is a way to fix this. My LCD screen is 16x2 but with only 16 pin (LED backlight).
I followed the tutorial on https://learn.adafruit.com/character-lcd-with-raspberry-pi-or-beaglebone-black/wiring except for pin 16 connected to the 5V.

• I'm using RPI 2 B with Jessie
• Python 2.7.9
• No message/traces, I'm using char_lcd.py and nothing happen when I call lcd.set_backlight(0). Same result if I replace it with lcd.enable_display(0)

I hope you can help me!
Art'