Go to advanced search

by pcmanbob
Tue Jun 22, 2021 7:03 am
Forum: Automation, sensing and robotics
Topic: Controlling 5V fan from GPIO pin with PWM
Replies: 12
Views: 507

Re: Controlling 5V fan from GPIO pin with PWM

What frequency did you set the pwm to ?

Try changing it to some thing else 50 or 100 are what people tend to use.
by pcmanbob
Mon Jun 21, 2021 10:20 am
Forum: Automation, sensing and robotics
Topic: Controlling 5V fan from GPIO pin with PWM
Replies: 12
Views: 507

Re: Controlling 5V fan from GPIO pin with PWM

killwater wrote:
Sun Jun 20, 2021 11:43 pm
Jsut one more question - can I use S8050 instead of 2n2222? Would 1k resistor still be sufficient?
The transistor will carry the load of the fan but you may have to lower the resistor value to obtain full voltage/current to the fan.
by pcmanbob
Sun Jun 20, 2021 5:06 pm
Forum: Beginners
Topic: DC Motor Control Options for a dozen, or more motors
Replies: 8
Views: 256

Re: DC Motor Control Options for a dozen, or more motors

Thank you @rpdom, this is the kind if tip I was looking for One direction is all that I need. I'll take a look at the ULN2801 Thanks again! I would recommend you use the ULN2803A with the pi, it will work directly with the gpio pins and has the correct 2.7K resistor built in for the input, to limit...
by pcmanbob
Sat Jun 19, 2021 10:48 am
Forum: General discussion
Topic: 3A+ Doesn't Like Channel 1 ?
Replies: 13
Views: 423

Re: 3A+ Doesn't Like Channel 1 ?

As you say app on phone wont show anything because its not an actual wifi signal , you would need actual radio wave detection kit to see other transmissions in the 2.4GHz frequency range. If it only happens a certain times of the day it might give you a clue, like around meal times might indicate a ...
by pcmanbob
Sat Jun 19, 2021 8:56 am
Forum: General discussion
Topic: 3A+ Doesn't Like Channel 1 ?
Replies: 13
Views: 423

Re: 3A+ Doesn't Like Channel 1 ?

May be its some local interference that's causing the problem , wireless door bells , wireless remotes, even micro waves. Also how far from the wifi access point is you pi , I have a pi zero that's out in my garage , when we get bad weather it often disconnects. never had a problem with a pi not con...
by pcmanbob
Sat Jun 19, 2021 8:49 am
Forum: General programming discussion
Topic: Playing audio in loop with breaks.
Replies: 4
Views: 162

Re: Playing audio in loop with breaks.

So which programming language are you using ?

what code have you got so far ?
by pcmanbob
Sat Jun 19, 2021 8:43 am
Forum: Other projects
Topic: PI Zero W - Hottub Controller - Help needed
Replies: 11
Views: 411

Re: PI Zero W - Hottub Controller - Help needed

The first thing I am going to tell you that your driver chip is not the greatest thing to interface with the pi. Because mosfets are what should be used. But its not impossible to get them working, but you need to use safety circuits to protect your pi. Here is a method of implementing a safety cir...
by pcmanbob
Fri Jun 18, 2021 6:52 pm
Forum: Python
Topic: Simple python code to read temp from DS18B20 sensor
Replies: 4
Views: 217

Re: Simple python code to read temp from DS18B20 sensor

Have you tried the examples on the w1thermsensor 2.0.0 page ?

https://pypi.org/project/w1thermsensor/

It covers one or multiple sensors.
by pcmanbob
Fri Jun 18, 2021 6:46 pm
Forum: Python
Topic: Reading GPIO Ping used on other script
Replies: 6
Views: 210

Re: Reading GPIO Ping used on other script

You can do what you want if you use RPi.GPIO . So here are 2 programs to demonstrate . Output code import RPi.GPIO as GPIO import time GPIO.setmode(GPIO.BCM) GPIO.setwarnings(False) GPIO.setup(8, GPIO.OUT) while True: GPIO.output(8, GPIO.HIGH) time.sleep(5) GPIO.output(8, GPIO.LOW) time.sleep(5) her...
by pcmanbob
Fri Jun 18, 2021 12:38 pm
Forum: Gaming
Topic: arcade controller question
Replies: 5
Views: 383

Re: arcade controller question

Having looked at this again you might be lucky if the information in the product description is correct . Compatible model Win8/Win7/Vista/XP/2000/98, Linux, MAC OS, Android.Raspberry Pi 1/2/3/3B Retropie Arcade DIY Projects,MAME DIY projects,USB MAME cabinet arcade DIY projects & PC controller ...
by pcmanbob
Fri Jun 18, 2021 12:34 pm
Forum: Automation, sensing and robotics
Topic: 5V Relay without transistor?
Replies: 15
Views: 661

Re: 5V Relay without transistor?

The only thing I see is a missing link between 5V and Vcc-JD , unless you still have the jumper on VCC & Vcc-JD.

I would advise you to solder a socket on your PCB and fit the ULN2803A after soldering , so you don't risk damaging the chip by over heating it while soldering.
by pcmanbob
Fri Jun 18, 2021 8:07 am
Forum: General discussion
Topic: stepper motor and l293d motor driver
Replies: 1
Views: 96

Re: stepper motor and l293d motor driver

Assuming you have the motor connected correctly and in the same way as I did, try this code import RPi.GPIO as GPIO import time # Variables delay = 0.5025 steps = 10 GPIO.setmode(GPIO.BCM) GPIO.setwarnings(False) # Enable pins for IN1-4 to control step sequence coil_A_1_pin = 23 coil_A_2_pin = 24 co...
by pcmanbob
Thu Jun 17, 2021 8:42 am
Forum: Gaming
Topic: arcade controller question
Replies: 5
Views: 383

Re: arcade controller question

Hi.

As everything appears to be switch based you could certainly connect the switches directly to the gpio pins.

I am not sure about the USB controllers they may need a driver..
by pcmanbob
Wed Jun 16, 2021 7:06 pm
Forum: Other projects
Topic: PI Zero W - Hottub Controller - Help needed
Replies: 11
Views: 411

Re: PI Zero W - Hottub Controller - Help needed

As I said without more details about the relay board shown it's impossible to give exact advice, but if the board is using 12V I would suggest you use opto isolators between the pi gpio and the relay board.

Then you can totally isolated the pi 5V and ground from the relay board.
by pcmanbob
Wed Jun 16, 2021 7:01 pm
Forum: Python
Topic: Play sound Python
Replies: 1
Views: 164

Re: Play sound Python

Hi. You have not said what sensor you intend to use, so how can we point you at suitable code. I suggest you do a search for which ever sensor you intend to use and how to connect it to you pi most examples will probably include example code. If you do a web search like this you will find lots of ex...
by pcmanbob
Tue Jun 15, 2021 8:12 am
Forum: General discussion
Topic: wrong signals from limit switches when connected with pump
Replies: 2
Views: 141

Re: wrong signals from limit switches when connected with pump

Without knowing how you have all this wired up its going to be very difficult for use to workout whats going wrong . For a start I suggest you post a wiring diagram of the circuit as you think you have wired it and some pictures of the actual wiring/components. I might also be a good idea to include...
by pcmanbob
Mon Jun 14, 2021 2:49 pm
Forum: Automation, sensing and robotics
Topic: Controlling 5V fan from GPIO pin with PWM
Replies: 12
Views: 507

Re: Controlling 5V fan from GPIO pin with PWM

To control you fan you need to use a transistor like this.

Image

it assumes the 3rd wire is just for speed output.
by pcmanbob
Mon Jun 14, 2021 2:39 pm
Forum: General discussion
Topic: printout from python to txt ?
Replies: 32
Views: 822

Re: printout from python to txt ?

Try changing this line

Code: Select all

python3  /home/pi/BLE.py>/home/pi/logs/BLE.txt 2>&1 &
to this line

Code: Select all

python3  /home/pi/BLE.py >>/home/pi/logs/BLE.txt 2>&1 &
so that you append all output to the file and not over writing on each new entry.
by pcmanbob
Wed Jun 09, 2021 8:48 am
Forum: Python
Topic: LCD Configuration
Replies: 2
Views: 42403

Re: LCD Configuration

Hi. You have not provided enough information for anyone to be able to help you, we cant see your pi or what code you are running on it. you need to provide a lot more detail . I would start with a link to the tutorial your are trying to follow post the code you are running on your pi to drive/displa...
by pcmanbob
Wed Jun 09, 2021 8:42 am
Forum: Automation, sensing and robotics
Topic: 3 volt chip led with relay ?
Replies: 14
Views: 547

Re: 3 volt chip led with relay ?

And to add to what rpdom has posted .

If you wanted to drive the LED at 20mA @3V you could use a simple 2N2222 and a couple of resistors like this

Image
by pcmanbob
Wed Jun 09, 2021 8:34 am
Forum: Other projects
Topic: PI Zero W - Hottub Controller - Help needed
Replies: 11
Views: 411

Re: PI Zero W - Hottub Controller - Help needed

Sorry I was unclear the first picture is the board that I am replacing, that is the current control board that drives the relay board. the other 3 pictures are the relay board that i will be using. The original control board had a unl2003a but i am not using that, that was just to show what i am tr...
by pcmanbob
Tue Jun 08, 2021 10:25 pm
Forum: Automation, sensing and robotics
Topic: 3 volt chip led with relay ?
Replies: 14
Views: 547

Re: 3 volt chip led with relay ?

petercli wrote:
Tue Jun 08, 2021 10:08 pm
I want the led to turn off and on from python based on logic in the program.
Then as I asked in my previous post give us the details of the LED then we might be able to help you,

Without the information we have nothing to work with.
by pcmanbob
Tue Jun 08, 2021 10:03 pm
Forum: Other projects
Topic: PI Zero W - Hottub Controller - Help needed
Replies: 11
Views: 411

Re: PI Zero W - Hottub Controller - Help needed

So the unl2003a is already in the relay board in the hot tube controller ?

And you are trying to drive this using the gpio pins on your pi via the header you show in your first picture ?

Or are you replacing this board with a cheap relay board designed for use with the pi/Arduino ?
by pcmanbob
Tue Jun 08, 2021 9:56 pm
Forum: Automation, sensing and robotics
Topic: 3 volt chip led with relay ?
Replies: 14
Views: 547

Re: 3 volt chip led with relay ?

Is there some reason you want to use a relay to control an LED ?

Depending on the current the LED draws you could drive it directly with an npn or MOSFET transistor.

Do you have a link to the LED in question.
by pcmanbob
Tue Jun 08, 2021 8:21 pm
Forum: Other projects
Topic: PI Zero W - Hottub Controller - Help needed
Replies: 11
Views: 411

Re: PI Zero W - Hottub Controller - Help needed

Have you got a link to the relay board you are using ?

Then I can check your diagram as you will need a pi ground connection to the ULN2003A.

Go to advanced search