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by bgreat
Fri Feb 15, 2013 7:21 pm
Forum: Troubleshooting
Topic: How to make raspberry stable ?
Replies: 28
Views: 10303

Re: How to make raspberry stable ?

I would try replacing the power supply and micro-usb cable being used for the power. I find the Raspberry Pi to be very stable. I have three currently running 24/7. All three run overclocked with Raspbian Wheezy (Dec-2012) as the OS. My first Pi is a Rev. 1 256MB running as a headless server on wire...
by bgreat
Fri Feb 15, 2013 1:15 pm
Forum: Python
Topic: buttons and pcf8574 in python
Replies: 6
Views: 10330

Re: buttons and pcf8574 in python

You need to enable i2c support on the Raspberry Pi and install the python-smbus package. There are several threads and web pages that tell you how. Simple test: #!/usr/bin/env python import smbus import time # i2c address of PCF8574 PCF8574=0x20 # open the bus (0 -- original Pi, 1 -- Rev 2 Pi) b=smb...
by bgreat
Fri Feb 15, 2013 1:01 pm
Forum: Русский
Topic: Serial Console
Replies: 5
Views: 2724

Re: Serial Console

There is a thread that discusses eliminating the uart: "Uncompressing Linux..." message. The key was to use an uncompressed kernel image. Command summary from thread (as root): # dd if=kernel.img skip=1 bs=17836 | gzip -d >kernel_uncompressed.img The "bs" value may be different for you depending on ...
by bgreat
Fri Feb 15, 2013 2:38 am
Forum: Other projects
Topic: Problems with 2x16 LCD displays
Replies: 7
Views: 2595

Re: Problems with 2x16 LCD displays

Using an external supply for the display will work. But, you must connect the ground from the external supply to the Raspberry Pi ground. This provides the common reference for the signal levels.

Enjoy!
Bill
by bgreat
Thu Feb 14, 2013 1:26 pm
Forum: Python
Topic: pwm control from python
Replies: 6
Views: 2200

Re: pwm control from python

Just a couple of points 1 - I've never personally got wiringpi to work in python - but that's just me :) I have found WiringPi to work well for general GPIO and PWM from Python. My only problem was getting my head around the different pin numbering schemes (which is why my code has the detailed com...
by bgreat
Thu Feb 14, 2013 1:12 pm
Forum: General programming discussion
Topic: Configure any GPIO to work as I2C
Replies: 7
Views: 1622

Re: Configure any GPIO to work as I2C

Each GPIO pin can be programmed for a specific subset of the available alternate functions. You can refer to BCM2835 ARM Peripherals - Raspberry Pi for the detailed specifics.

Enjoy!
Bill
by bgreat
Thu Feb 14, 2013 12:53 am
Forum: Python
Topic: pwm control from python
Replies: 6
Views: 2200

Re: pwm control from python

WiringPi has everything you need for PWM control via Python. I use it with my Nokia SPI display to control the back light brightness. The thread on the forums has the code. Here is a quick excerpt for using the PWM: #!/usr/bin/env python import wiringpi #gpio's : LED = 1 # gpio pin 12 = wiringpi no....
by bgreat
Wed Feb 13, 2013 11:22 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Enable both I2C Busses
Replies: 58
Views: 32502

Re: Enable both I2C Busses

The only thing that comes to mind is pull-up resistors on the SDA0/SCLK0 lines. Since the P5 lines are not designated as I2C by default, you need to add your own resistors.

Enjoy!
Bill
by bgreat
Wed Feb 13, 2013 7:58 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Enable both I2C Busses
Replies: 58
Views: 32502

Re: Enable both I2C Busses

Here is my attempt to enable both I2C interfaces. It appears to work on my Raspberry Pi, but I do not have any I2C peripherals to test. i2c_p5.py: #!/usr/bin/env python # # W. Greathouse 13-Feb-2013 # # Enable I2C on P1 and P5 (Rev 2 boards only) # # ####### # For I2C configuration test import os im...
by bgreat
Wed Feb 13, 2013 5:19 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Enable both I2C Busses
Replies: 58
Views: 32502

Re: Enable both I2C Busses

You can look at my Python SPI reset code for the method. It is posted in the Nokia SPI display thread. If no one steps up, I'll post the Python code for the I2C configuration this evening when I get home. It should be possible to maintain use of both I2C buses, but you will lose the I2C bus on the S...
by bgreat
Wed Feb 13, 2013 4:46 pm
Forum: Beginners
Topic: 4 Bugs
Replies: 9
Views: 1669

Re: 4 Bugs

4) When I first turned the RPi on it asked whether I wanted ctrl-alt-del to end the X server. I said 'yes' and it doesn't. (ctrl-alt-left del opens task manager. ctrl-alt-numpad del does nothing.) I've had the X server hang while I was trying to solve problem 1) so this would have been useful. Is t...
by bgreat
Wed Feb 13, 2013 1:16 pm
Forum: Beginners
Topic: Frustrated with project
Replies: 12
Views: 2051

Re: Frustrated with project

I now understand why the loops are set to "False." Basically, the switch and the GPIO input are connected in parallel, so when the low-resistance switch is pressed, most of the current flows through it to ground instead of to the GPIO pin. Is that accurate? If so, I understand why it would play mus...
by bgreat
Wed Feb 13, 2013 12:58 pm
Forum: Beginners
Topic: Frustrated with project
Replies: 12
Views: 2051

Re: Frustrated with project

Post your code, dude! Chill! ;) The code is in the link from the first post. The code I posted for testing is the same code plus comments and the sound calls replaced with print statements. Of course, posting the actual code would allow confirmation of the indenting. I assume this is correct, since...
by bgreat
Wed Feb 13, 2013 12:51 pm
Forum: Русский
Topic: Serial Console
Replies: 5
Views: 2724

Re: Serial Console

:oops: Thanks. I debated on the stock answer because of the translation quality. But seeing as no answers were posted, I wanted to be sure he was aware of the set up required.

Enjoy!
Bill
by bgreat
Tue Feb 12, 2013 7:06 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Invert GPIO RxD pin (solved)
Replies: 26
Views: 17349

Re: Invert GPIO RxD pin (solved)

Unless the meter was actually outputting RS-232 levels where >= +3v is logic 0, <= -3v is logic 1.

Enjoy!
Bill
by bgreat
Tue Feb 12, 2013 1:52 pm
Forum: Python
Topic: Nokia Pi LCD
Replies: 253
Views: 112121

Re: Nokia Pi LCD

Grandpa's Rule! :D

Enjoy!
Bill
by bgreat
Tue Feb 12, 2013 1:47 pm
Forum: Beginners
Topic: Frustrated with project
Replies: 12
Views: 2051

Re: Frustrated with project

And here is a simple drawing of the connections that are being used for the test. This may be easier to follow than the photo if you are unfamiliar with schematics and wiring. buttons.png When the buttons are unpressed, the resistors pull the corresponding GPIO pin to 3.3v (True) level. When the but...
by bgreat
Tue Feb 12, 2013 1:18 pm
Forum: Beginners
Topic: Frustrated with project
Replies: 12
Views: 2051

Re: Frustrated with project

To verify your buttons are working, try this as a first program. Once it is working, then change the print lines to play the sounds. #!/usr/bin/env python from time import sleep import os import RPi.GPIO as GPIO # Three buttons are connected to the BCM GPIO as follows button1 = 23 button2 = 24 butto...
by bgreat
Tue Feb 12, 2013 1:04 pm
Forum: Русский
Topic: Serial Console
Replies: 5
Views: 2724

Re: Serial Console

Здравствуй, Чтобы отключить последовательный порт в сообщениях Raspian Wheezy: 1. Отключение входа на редактирование "/etc/inittab" Изменить: T0:23:respawn:/sbin/getty -L ttyAMA0 115200 vt100 To: #T0:23:respawn:/sbin/getty -L ttyAMA0 115200 vt100 2. Отключить загрузку сообщений от редактирования "/b...
by bgreat
Sun Feb 10, 2013 8:56 pm
Forum: General discussion
Topic: How to connect to a network printer?
Replies: 2
Views: 1010

Re: How to connect to a network printer?

The Raspberry Pi Wheezy distribution (and possibly others) does support CUPS for printing. If you are unfamiliar with CUPS, then this article appears to be a reasonable introduction for using CUPS on the Raspberry Pi: Linux printing using CUPS (Raspberry Pi).

Enjoy!
Bill
by bgreat
Sun Feb 10, 2013 8:50 pm
Forum: Other projects
Topic: Controlling GPIO in using GPIO out
Replies: 3
Views: 1329

Re: Controlling GPIO in using GPIO out

You need to read the input value before testing... GPIO.output(22, True) print ("Output high") time.sleep(1) input_value = GPIO.input(12) if input_value == True: print ("Input high") else: print ("Input low") The "=" does not assign a functionality to input_value, it executes the "GPIO.input(12)" fu...
by bgreat
Sun Feb 10, 2013 1:44 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Enable both I2C Busses
Replies: 58
Views: 32502

Re: Enable both I2C Busses

Just be aware that it was intended the P5 connection would be on the bottom so as not to interfere with P1. Your soldering will be on the top in this case. With the 2.54 mm spacing for the header, this is "easy" soldering, so you should not be overly concerned if you have reasonable skill with a low...
by bgreat
Sun Feb 10, 2013 1:28 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: uart: "Uncompressing Linux..."
Replies: 12
Views: 6298

Re: uart: "Uncompressing Linux..."

If you mean CTS/RTS, they are available on P5. Though I do not see what that has to do with using differential signalling. I believe the intended reference was for RS-485 multidrop signalling where the RTS line may be used to for controlling the transmitter state. RTS0 is also available on P1 (alte...
by bgreat
Sun Feb 10, 2013 1:18 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Enable both I2C Busses
Replies: 58
Views: 32502

Re: Enable both I2C Busses

I2C bus 0 is available as an alternate function of GPIO 28 and GPIO 29 pins available on the P5 connector for the Rev 2 Raspberry Pi boards. I2C bus 1 is available on the P1 connector for Rev 2 Raspberry Pi boards. By default no connector is installed for P5 -- you can install your own 8 pin header....
by bgreat
Sat Feb 09, 2013 10:12 pm
Forum: Automation, sensing and robotics
Topic: GPIO LED showing network connection
Replies: 3
Views: 2608

Re: GPIO LED showing network connection

Here is a simple C application that will print the current state of an interface. You can enter the interface name as an argument, otherwise it defaults to eth0. if_flags.c: /********************************************************************/ /* Simple network interface status application */ /* Op...

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