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by scotty101
Tue Feb 20, 2018 6:01 pm
Forum: General discussion
Topic: Showing a Pi can replace a standard computer
Replies: 7
Views: 218

Re: Showing a Pi can replace a standard computer

Check out MagPi Issue 59

It contains an article about someone replacing their 'normal computer' with a Pi, what limitations it had/what it did well.
by scotty101
Tue Feb 20, 2018 5:57 pm
Forum: Beginners
Topic: Running a Procedure from a tkinter button or an event
Replies: 14
Views: 309

Re: Running a Procedure from a tkinter button or an event

I'm sure I told you about that too in the example I provided before.

viewtopic.php?f=91&t=203759&p=1265081#p1265053
by scotty101
Tue Feb 20, 2018 12:32 pm
Forum: Python
Topic: Python issue: Getting a "cannot import name ttk" error
Replies: 2
Views: 46

Re: Python issue: Getting a "cannot import name ttk" error

Are you sure you are running python 2?

If you are using python 2, my advice would be to move to Python 3 unless you have a really good reason not to.

With python 3 you import the ttk 'extensions' using

Code: Select all

from tkinter import ttk
by scotty101
Mon Feb 19, 2018 9:14 pm
Forum: Advanced users
Topic: Is it posible to use a cluster in this way....
Replies: 5
Views: 121

Re: Is it posible to use a cluster in this way....

Clusters only work if the software has been developed to work across multiple devices.
Standard applications haven't been built to support this.
by scotty101
Mon Feb 19, 2018 4:29 pm
Forum: Other projects
Topic: 3x4 matrix combined with 16x2 LCD I2C Adafruit
Replies: 14
Views: 3533

Re: 3x4 matrix combined with 16x2 LCD I2C Adafruit

Then share the code you are running and post the exact error message that you are getting.

Do you perhaps have something else inside your python script called LCD?
by scotty101
Mon Feb 19, 2018 4:16 pm
Forum: Beginners
Topic: How can I link data from users to the Http page?
Replies: 3
Views: 65

Re: How can I link data from users to the Http page?

Perhaps you can explain your current setup. How is your sensor currently connected to the Pi and how is the data currently read and sent to cloudmqtt? Perhaps you could just have the same program/script that sends the data to cloudmqtt record data to a local database where it can be accessed by a se...
by scotty101
Mon Feb 19, 2018 3:07 pm
Forum: General discussion
Topic: First Time (Potential) User - Need Info
Replies: 4
Views: 109

Re: First Time (Potential) User - Need Info

There is no Pi model that has built in A/D converters. In all cases you would need external circuitry such as a plugin board (HAT). If you are a Noob, stick with the Raspberry Pi 3. Once you've used that and if you decide you need something smaller/less powerful, swap to something else. As for learn...
by scotty101
Mon Feb 19, 2018 2:59 pm
Forum: Other projects
Topic: 3x4 matrix combined with 16x2 LCD I2C Adafruit
Replies: 14
Views: 3533

Re: 3x4 matrix combined with 16x2 LCD I2C Adafruit

Try changing

Code: Select all

import Adafruit_CharLCD as LCDimport
to

Code: Select all

import Adafruit_CharLCD as LCD
Also have you installed the Adafruit LCD library?
by scotty101
Mon Feb 19, 2018 1:13 pm
Forum: Automation, sensing and robotics
Topic: line follow with obstacle
Replies: 17
Views: 373

Re: line follow with obstacle

That seems to be the common way to control the L298N (I've never used it before but have used similar) See http://howtomechatronics.com/tutorials/arduino/arduino-dc-motor-control-tutorial-l298n-pwm-h-bridge/ . The example Arduino code shows the PWM being applied to the ENA pin rather than the IN pin...
by scotty101
Mon Feb 19, 2018 9:40 am
Forum: Automation, sensing and robotics
Topic: line follow with obstacle
Replies: 17
Views: 373

Re: line follow with obstacle

I can't run your code since I don't have a pi and all the required parts but this looks incorrect SPD=input("speed?? enter 20/40/60/100") p1=GPIO.PWM(7,SPD) Using the input command you read in a string containing 20,40,60 or 100. You then pass that string to the GPIO.PWM method. This will probably f...
by scotty101
Fri Feb 16, 2018 8:19 pm
Forum: Other projects
Topic: RPI and IMU for automatic leveling of a camper
Replies: 2
Views: 97

Re: RPI and IMU for automatic leveling of a camper

Amazing project! Really well executed and brilliant use of a pi. You should be on the cover of the MagPi!
by scotty101
Fri Feb 16, 2018 2:27 pm
Forum: Beginners
Topic: Running a Procedure from a tkinter button or an event
Replies: 14
Views: 309

Re: Running a Procedure from a tkinter button or an event

Following on from Paeryn's comments about your gauges, I've dug out an old example of a tkinter gauge I created back. It updates the pointer''s coordinates rather than deleting or drawing over the top. Its not very neat but I may update this post with a cleaner example. Currently the gauge just move...
by scotty101
Fri Feb 16, 2018 9:49 am
Forum: Automation, sensing and robotics
Topic: Any easy way to sync two RPis?
Replies: 3
Views: 217

Re: Any easy way to sync two RPis?

Would it make the most sense to use the TX/RX (14/15)? Tx -> Rx Rx -> Tx Gnd -> Gnd The quickest would be a single GPIO pin that changes state to signal to take the photograph. Using the serial port will result in a slightly longer delay between the command being sent, received and processed by the...
by scotty101
Thu Feb 15, 2018 9:28 pm
Forum: Beginners
Topic: Running a Procedure from a tkinter button or an event
Replies: 14
Views: 309

Re: Running a Procedure from a tkinter button or an event

The issue is that a GPIO callback event passes the channel of the GPIO pin as an argument to the callback function. Summary: GPIO Callback passes 1 parameter Now the tkinter button press callback does not pass any arguments Summary: Tkinter 0 parameters My proposed solution is that you have the GPIO...
by scotty101
Thu Feb 15, 2018 5:03 pm
Forum: Troubleshooting
Topic: Reviving two PIs by doing nothing for 2 months
Replies: 10
Views: 388

Re: Reviving two PIs by doing nothing for 2 months

pcmanbob wrote:
Thu Feb 15, 2018 4:19 pm
scotty101 wrote:
Thu Feb 15, 2018 4:16 pm
Sounds like the polyfuses have had time to reset.
Problem with that statement is the Pi Zero W and Pi Zero don't have poly-fuses.
Good point, well made!
by scotty101
Thu Feb 15, 2018 4:23 pm
Forum: General discussion
Topic: Questions about Pi3 , Node-Red and MQTT
Replies: 9
Views: 368

Re: Questions about Pi3 , Node-Red and MQTT

Is it possible to connect many ds18b20 sensors? As there is only 1-wire GPIO as far I know.
Yes. You can connect multiple ds18b20 sensors to the same GPIO. They will appear on the Pi with different addresses.
by scotty101
Thu Feb 15, 2018 4:20 pm
Forum: Troubleshooting
Topic: Python don't work with GPIO Pins
Replies: 2
Views: 74

Re: Python don't work with GPIO Pins

With a script just containing the below text, what error message do you get. Please reply with the exact error message. import RPI.GPIO as GPIO Some other question too; How do you run your scripts? Which version of python are you using? Which OS are you using? Is it a standard Raspbian installation?
by scotty101
Thu Feb 15, 2018 4:16 pm
Forum: Troubleshooting
Topic: Reviving two PIs by doing nothing for 2 months
Replies: 10
Views: 388

Re: Reviving two PIs by doing nothing for 2 months

Sounds like the polyfuses have had time to reset.
by scotty101
Thu Feb 15, 2018 11:53 am
Forum: Beginners
Topic: Running a Procedure from a tkinter button or an event
Replies: 14
Views: 309

Re: Running a Procedure from a tkinter button or an event

Share your code or a small working example of it that demonstrates your problem.
I'll then be able to help.
by scotty101
Thu Feb 15, 2018 11:49 am
Forum: General discussion
Topic: Pi Zero W as Controller
Replies: 4
Views: 181

Re: Pi Zero W as Controller

This sounds like a perfect scenario for MQTT. You have a single Pi acting as the central server (or broker) which all the other pi's communicate with. With MQTT each device can publish and subscribe to certain messages. For example you could have each node send out its temperature, the message might...
by scotty101
Thu Feb 15, 2018 11:37 am
Forum: Automation, sensing and robotics
Topic: Controling 6 homemade solenoids
Replies: 5
Views: 221

Re: Controling 6 homemade solenoids

Build your solenoids first. Once you have connect them to a power supply and a multimeter to see how much current they draw. Once you have those figures you can select a suitable driver. Personally, I think I'd go for a traditional relay switch rather than a darlington transistor IC. Greater isolati...
by scotty101
Wed Feb 14, 2018 4:49 pm
Forum: General discussion
Topic: MPEG2 patent expiration
Replies: 1
Views: 183

Re: MPEG2 patent expiration

There is already a topic related to this

See viewtopic.php?f=67&t=201449
by scotty101
Wed Feb 14, 2018 4:44 pm
Forum: Beginners
Topic: Can anyone here help a beginner with PHP
Replies: 3
Views: 143

Re: Can anyone here help a beginner with PHP

What instructions did you follow to install a webserver and PHP?

Your results suggest that PHP hasn't been configured to work with the webserver (Apache?)
by scotty101
Wed Feb 14, 2018 3:22 pm
Forum: Troubleshooting
Topic: How to load modules into Python 3
Replies: 3
Views: 85

Re: How to load modules into Python 3

Why do you need to find them in the site-packages folder?

If a pip3 installation has been successful you should just be able to use `import mymodulename` from in your python script to use the module.
by scotty101
Wed Feb 14, 2018 3:16 pm
Forum: Beginners
Topic: Running a .NET app
Replies: 1
Views: 63

Re: Running a .NET app

Create a systemd service to start your application on boot.

https://www.raspberrypi.org/documentati ... systemd.md

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