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by pcmanbob
Fri Apr 19, 2019 3:16 pm
Forum: Automation, sensing and robotics
Topic: Looking for help with DHT11 humidity and temperature sensor
Replies: 12
Views: 326

Re: Looking for help with DHT11 humidity and temperature sensor

So assuming your sensor has a 10 pull up resistor fitter ( I cant see what's actually on your sensor pcb ) then the connection's look good, if you followed the instructions and changed the code to read gpio 17 , I don't see why its not working.
by pcmanbob
Thu Apr 18, 2019 7:10 pm
Forum: Python
Topic: placing 2-dim arrays into 3-dim sheets
Replies: 6
Views: 115

Re: placing 2-dim arrays into 3-dim sheets

As 99.9% of people here are just other pi users it my be that no one that has looked at your post has any idea on how to solve your problem.

It can take days for the right person to see your post, 24 hours is a very short time for that to occur.
by pcmanbob
Thu Apr 18, 2019 1:22 pm
Forum: Beginners
Topic: Using Sensor and Pi outside
Replies: 14
Views: 257

Re: Using Sensor and Pi outside

Glad you got your MCP3008 to work. I have no idea what sort of reading you should get from your sensor but don't forget you are measuring a 5v output from the sensor, its just that you are converting that 5v to 3.3v , I assume you did calibrate the potential divider circuit by connecting a 5v supply...
by pcmanbob
Thu Apr 18, 2019 12:02 pm
Forum: Automation, sensing and robotics
Topic: Robotics project PLEASE HELP!
Replies: 5
Views: 106

Re: Robotics project PLEASE HELP!

Looking at the schematic digram in the link posted you need to connect a 12VDC power supply to the indicated terminal to power the motors from, making sure to connect it the right way round. The 5v from the pi will only drive the electronics/control circuit and not the motors. https://i.imgur.com/v8...
by pcmanbob
Thu Apr 18, 2019 11:49 am
Forum: Troubleshooting
Topic: PI 3 keeps rebooting
Replies: 6
Views: 102

Re: PI 3 keeps rebooting

Hi. As with all problems relating to a pi continuously rebooting on start up, the first question always is, what are you using as a power supply ? It would also help to know exactly which model of pi you are using ? Might also help to explain exactly what you did to rotate your screen, including whi...
by pcmanbob
Thu Apr 18, 2019 11:32 am
Forum: General discussion
Topic: upgrading my vending machine to touch screen
Replies: 8
Views: 273

Re: upgrading my vending machine to touch screen

From the ViewSonic Online Support Center
ViewSonic does not currently have Linux drivers for any of our devices
So I am guessing no support for Linux or ARM processors out of the box.
by pcmanbob
Wed Apr 17, 2019 6:54 pm
Forum: General discussion
Topic: upgrading my vending machine to touch screen
Replies: 8
Views: 273

Re: upgrading my vending machine to touch screen

Yes you can connect a 24" hdmi monitor to a pi, but it's unlikely to be touch enabled.
by pcmanbob
Wed Apr 17, 2019 6:04 pm
Forum: Beginners
Topic: SCREEN
Replies: 13
Views: 252

Re: SCREEN

First off please don't shout ( using all capitals is considered as shouting on a forum ) it will not get you an answer any quicker. Secondly as you have not said were in the world you are how can anyone tell you what's available were you are. And lastly is Google broken were you are ? You are just a...
by pcmanbob
Wed Apr 17, 2019 12:23 pm
Forum: Troubleshooting
Topic: Controlling LED on GPIO3
Replies: 7
Views: 136

Re: Controlling LED on GPIO3

Have you not understood what people have been telling you , you can not drive a blue LED directly from a gpio pin with no limiting resistor , you will eventually damage you pi to the point were it will not work at all. I suspect what you are seeing is the pi failing after 40 min due to the excessive...
by pcmanbob
Wed Apr 17, 2019 12:11 pm
Forum: General discussion
Topic: Thunderbird Won't Accept E-mail Password
Replies: 2
Views: 75

Re: Thunderbird Won't Accept E-mail Password

Hi.

You have provided to little information for anyone to give you a meaningful replay.

We can see you pi so you need to tell us in detail what happens, saying it wont accept it tell us nothing.

Please explain in detail

what you're doing
what happens
what you expect to happen
by pcmanbob
Wed Apr 17, 2019 12:05 pm
Forum: General discussion
Topic: Connecting a tactile switch
Replies: 28
Views: 854

Re: Connecting a tactile switch

The switch will still work physically at the same speed it always has, changing resistor values wont change that, what you are probably seeing is that now you have the switch wired correctly your program needs to be adjusted to check the switch more often. Its the program that will define how fast i...
by pcmanbob
Tue Apr 16, 2019 10:16 am
Forum: Networking and servers
Topic: Anti Virus for FPS?
Replies: 1
Views: 65

Re: Anti Virus for FPS?

Hi.

I will direct you to this thread viewtopic.php?t=230440

I would also suggest you read this document on the raspberrypi.org site https://www.raspberrypi.org/documentati ... ecurity.md

I hope it helps.
by pcmanbob
Tue Apr 16, 2019 10:09 am
Forum: Automation, sensing and robotics
Topic: Voltage Datalogger (please help out a noob)
Replies: 4
Views: 153

Re: Voltage Datalogger (please help out a noob)

Hi. Seeing as one of you first statements is " pretty clueless, electrically illiterate " I would suggest this is not a project you should be attempting. Working with mains AC voltage is Dangerous, given the chance it will kill you or someone else and burn down your house. Designing/building any dev...
by pcmanbob
Tue Apr 16, 2019 9:34 am
Forum: Python
Topic: How to Auto-Execute Python file on Startup using Raspberry Pi 3
Replies: 24
Views: 933

Re: How to Auto-Execute Python file on Startup using Raspberry Pi 3

c2carey wrote:
Mon Apr 15, 2019 11:26 pm
pcmanbob, your post has:

@ python /home/pi/MyScript.py

I think that it should be

@reboot python /home/pi/MyScript.py

I am so thankful for your information!!!
Correct, was just a typo corrected now.
by pcmanbob
Mon Apr 15, 2019 5:11 pm
Forum: Beginners
Topic: Using Sensor and Pi outside
Replies: 14
Views: 257

Re: Using Sensor and Pi outside

All this discussion about I2C is all well and good but the MCP3008 uses SPI as I pointed out several posts ago, so I2C comments are totally irrelevant.

SPI pins are 3.3V only so MCP3008 is limited to Vdd of 3.3V so can't measure an input of 5V.
by pcmanbob
Mon Apr 15, 2019 1:51 pm
Forum: Beginners
Topic: Using Sensor and Pi outside
Replies: 14
Views: 257

Re: Using Sensor and Pi outside

The reason I said 0-3.3v only was because in all the posts I have seen on this forum and on the examples on the web its always been stressed 3.3v max when connecting MCP3008 to pi gpio. Dougie have you actually tried it with vref at 5v and connected it to a pi ? Edit.... Dougie after reading your po...
by pcmanbob
Mon Apr 15, 2019 12:47 pm
Forum: Beginners
Topic: Using Sensor and Pi outside
Replies: 14
Views: 257

Re: Using Sensor and Pi outside

So assuming you have you MCP3008 connected up correctly the following code will read channel 0 and output the result as the voltage, once every second. #!/usr/bin/python import spidev import RPi.GPIO as GPIO import time import sys spi = spidev.SpiDev() # create spi object spi.open(0, 0) # open spi p...
by pcmanbob
Mon Apr 15, 2019 10:00 am
Forum: General discussion
Topic: upgrading my vending machine to touch screen
Replies: 8
Views: 273

Re: upgrading my vending machine to touch screen

1. so we are facing problems some times the programs get stuck into the start screen some times we cant swipe the items is it harware issue or software the software developer says i havent design the harddware its a hardware issue and hardware guys who programmed aurduino says its a software issue ...
by pcmanbob
Mon Apr 15, 2019 9:44 am
Forum: Raspbian
Topic: Raspberry Pi stops logging data
Replies: 1
Views: 34

Re: Raspberry Pi stops logging data

Hi. With so little information its hard to say what the cause might be. For example what does " the pi just turned off." actually mean , did it power off , the OS freeze , your program stopped running , you need to be more specific. One point I did notice is that you are running your program via a r...
by pcmanbob
Mon Apr 15, 2019 9:20 am
Forum: Advanced users
Topic: Relay Breakout Module with Opto-Isolation is uln2003a needed?
Replies: 2
Views: 64

Re: Relay Breakout Module with Opto-Isolation is uln2003a needed?

The reason people use a ULN2003A or a ULN2803A to drive relay boards is because the relay boards use 5v for the control circuit and active low, which means the pi gpio being 3.3v can turn the relays on but not off. see here : https://www.raspberrypi.org/forums/viewtopic.php?f=91&t=83372&p=1225448#p1...
by pcmanbob
Sun Apr 14, 2019 4:50 pm
Forum: General discussion
Topic: Connecting a tactile switch
Replies: 28
Views: 854

Re: Connecting a tactile switch

So you are still using a pull down circuit, I thought you said you had switched to a pull up circuit for your button ? https://i.imgur.com/0SDVlAJ.jpg So your are currently using the circuit on the right, did you actually try using the circuit on the left or did you just change the software pull-up/...
by pcmanbob
Sun Apr 14, 2019 3:13 pm
Forum: General discussion
Topic: Connecting a tactile switch
Replies: 28
Views: 854

Re: Connecting a tactile switch

You could try LAN cable as that has twisted pairs which might help, you could even try using several pairs to reduce the resistance over the length of cable being used.
by pcmanbob
Sun Apr 14, 2019 12:34 pm
Forum: Troubleshooting
Topic: Google Drive and Raspberry pi
Replies: 1
Views: 53

Re: Google Drive and Raspberry pi

Seeing as you have supplied no information about the problem what so ever, its very likely that no one will be able to help you.

One thing I can say is that if the same files can't be download on another pc either its likely its not a pi problem, but more likely a google drive problem.
by pcmanbob
Sat Apr 13, 2019 10:54 pm
Forum: Beginners
Topic: Ultrasonic sensor and 2 leds on a bread board
Replies: 5
Views: 132

Re: Ultrasonic sensor and 2 leds on a bread board

TO give a correct answerer to your connections, it would be better To draw your circuit out, and post it, Photos on breadboards can Be very confusing. Regards BoyOh The problem with a diagram is it won't show the sort of error that the pictures show here, were the resistor and wire are indifferent ...
by pcmanbob
Sat Apr 13, 2019 8:41 pm
Forum: General discussion
Topic: Connecting a tactile switch
Replies: 28
Views: 854

Re: Connecting a tactile switch

Looking back at the code you posted , on every call of the function you reset the gpio and set the input pin up again. That's not the way to do it, put the setmode line and the gpio.input line at the start of your program after the imports, you might have to define self before then as well. You only...

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