58
votes
Accepted
Can I use Raspberry Pi in commercial production?
You can embed the Raspberry Pi in any end-product you want.
For mass production, the Compute Module may be a better choice. The Compute Module is a Raspberry Pi in a more flexible form factor, ...
- 66.3k
29
votes
Accepted
Why are some GPIO pins HIGH when the Raspberry Pi boots up?
At powerup the GPIOs are pulled either high or low through the internal resistors. Whether the pull is high or low for a particular GPIO is detailed on page 102 of BCM2835 ARM Peripherals.
As the ...
- 66.3k
26
votes
Can I use Raspberry Pi in commercial production?
and I quote from Raspberry Pi's blog
If, like Brian, you’re making a product which requires a Raspberry Pi to run, we don’t ask you to buy special permission or licences from us to use it. All we ...
- 889
20
votes
gpio library on windows while developing
If you are just looking to test the whole code and not worry about the actual pins (as windows machines don't have GPIO), then you can fake it.
First, in your main python source directory, create a ...
- 331
16
votes
Can I use Raspberry Pi in commercial production?
It depends how you define "mass" in "mass production". If you're talking hundreds, the Pi is probably a good choice. If you're talking thousands, there might be "better" solutions available through ...
- 1,651
15
votes
Accepted
GPIO: Warning Channel already in use
This code helped me get rid of the warning (the "finally" part at the end):
import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BCM) # Broadcom pin-numbering scheme
GPIO.setup(6, GPIO.OUT) # ...
- 326
13
votes
Accepted
Plug a 5 V fan to GPIO 1 and 2
The diagram does not show pin numbers. Neither can I find anything on the diagram labelled 1.
The diagram does appear to correctly label the ground and 5V pins.
You can power a 5V fan by connecting ...
- 66.3k
13
votes
Can we use other GPIO pins as I2C
The whole point of I2C is it is a bus. You can therefore connect multiple I2C devices to the same GPIO provided they have different I2C device addresses.
If the devices share an address which can't ...
- 66.3k
12
votes
Why are some GPIO pins HIGH when the Raspberry Pi boots up?
When the Raspberry Pi boots the GPIO lines are reset to the chip default, then the OS is loaded and resets them to the OS default. There is no way to "remember" the settings across a reboot. See also ...
- 906
11
votes
How to correctly install the python RPi.GPIO library
Assuming you have pip, the python package index installer, which is installed on the latest versions of Raspbian by default
You can use:
sudo pip install RPi.GPIO for Python 2
and
sudo pip-3.2 ...
- 161
11
votes
Accepted
How fast can GPIO pins toggle?
There are some benchmarks from Henner Zeller's repository on GitHub which claimed that directly outputting data to the GPIO could achieve up to 65.8 MHz on a Raspberry Pi 3 (not B+, mind, but I ...
- 6,158
11
votes
gpiozero Button.when_pressed
It is possible to use parameters with callback functions. See e.g. Documentation for button.when_pressed
This can be set to a function which accepts no (mandatory) parameters,
or a Python ...
- 3,302
10
votes
Accepted
What hardware do I need to turn Raspberry Pi into a TV remote controller?
I have tried this one, it connects into the USB port, can record and play back the IR codes, supported by LiRC. I have even tried to plug it into my Android phone and it works there as well.
- 11.4k
10
votes
What hardware do I need to turn Raspberry Pi into a TV remote controller?
As an alternative to Infrared, you could use HDMI, if your TV has HDMI 2.0, it will support some kind of CEC (Consumer Electronics Control) implemenatation
Each TV brand calls this something else, ...
- 17.1k
10
votes
Accepted
Where are the uarts on the raspberry pi 4?
The preliminary Pi4 datasheet shows there are 6 UARTs.
UART GPIO
0 14/15
1 14/15
2 0/1
3 4/5
4 8/9
5 12/13
Given that UART 0/1 are both connected to the same GPIO you can only use ...
- 66.3k
9
votes
Webserver & GPIO python script (No access to /dev/mem. Try running as root!)
You don't so much need root access as permission to access the gpio device. Raspbian has a user group 'gpio' to enable this. By default the 'pi' user is in the gpio group and can access GPIOs. If you ...
- 481
9
votes
Is there any built in LED connected with GPIO pin?
Yes, it is possible to control the built-in leds. Green LED is easier.
According to here, though it is probably Pi 3 specific, since it didn't work for my Pi 4:
In the terminal:
sudo echo 1 > ...
- 1,574
8
votes
Toggling a GPIO pin set as output
Although stated elsewhere, you CAN read an output by just inputting the same GPIO pin and get the value returned you just set out before:
GPIO.setup(LED_red, GPIO.OUT) #set Pin LED_red as aoutput
...
- 81
8
votes
Importing RPi.GPIO
To answer your main question, no there is nothing syntactically wrong with writing:
import RPi.GPIO as g
g.setmode(GPIO.BCM)
#etc...
However, I would seriously evaluate what you are trying to do if ...
- 578
8
votes
Accepted
Is there documentation for RPi.GPIO
The official documentation is http://sourceforge.net/p/raspberry-gpio-python/wiki/Examples/
It doesn't seem to have a traditional API style of documentation.
- 66.3k
8
votes
Accepted
Can you connect multiple GPIO pins, to one ground pin?
Setting aside the ill-phrased part of the question (connecting multiple GPIO pins (which to my knowledge are 3 volts), to one ground pin) - which indeed short circuits the GPIO pins if they are set to ...
- 15.5k
8
votes
I can't get three LED lights to turn off and on in an order
You need to set the pin as an output before you use it.
To do that add the following line:
GPIO.setup(red, GPIO.OUT)
below the matching lines for green and yellow:
GPIO.setup(yellow, GPIO.OUT) ...
- 34k
8
votes
Debouncing buttons with RPi.GPIO -- too many events detected?
As @joan points out, the bouncetime parameter in RPi.GPIO does almost exactly the wrong thing: it means when your switch bounces, you'll get the very first event, but that may not actually be ...
- 646
8
votes
Accepted
Error installing RPi.GPIO in virtual environment
It looks like the latest release does not support Python 3.9 but the alpha releases do: https://www.piwheels.org/project/RPi.GPIO/
You can install the alpha version with:
pip install rpi-gpio --pre
- 2,361
7
votes
RPi.GPIO not found in virtual environment
The problem is that you don't have the GPIO module installed in your virtual environment. To correct this, run the following from within your virtual environment:
for Python 2
pip install RPi.GPIO
...
- 34k
7
votes
Accepted
Is the gpio readall command compatible with RPi 4?
As far as I am aware it should work provided you download and install the latest version of wiringPi.
http://wiringpi.com/wiringpi-updated-to-2-52-for-the-raspberry-pi-4b/
cd /tmp
wget https://...
- 66.3k
7
votes
Is there any built in LED connected with GPIO pin?
though it is probably Pi 3 specific, since it didn't work for my Pi 4
It works on the 4 as well, you just need to set the right trigger. The instructions that you provided are not applicable to the 4 ...
- 71
7
votes
Install GPIO problem
You can't install RPi.GPIO on Windows. If you want to mock GPIO calls on a PC, try gpiozero which has a mock pin interface: https://gpiozero.readthedocs.io/en/stable/api_pins.html
- 2,361
6
votes
How to correctly install the python RPi.GPIO library
Another potential cause could be because the RPi.GPIO library has C bindings and therefore need to have python-dev installed in order to compile correctly when installing.
Make sure you've got the ...
- 161
6
votes
how to turn on and off an led with only a tactile button
You can also use interrupts, which are quite useful in many other settings as well. This way, you can have your script do other things while you play with the button and the LED.
import RPi.GPIO as ...
- 161
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