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by boyoh
Mon Nov 29, 2021 9:50 am
Forum: Troubleshooting
Topic: Trying to understand what I did with my GPIO...
Replies: 8
Views: 198

Re: Trying to understand what I did with my GPIO...

Hi All I am having two buzzer modules (with transistors etc.), active and passive. For long time i had an active buzzer connected. I was working fine. Active buzzer is sort of activated on low signal for some reason. Anyway... Today i was playing around with passive buzzer trying to get some differ...
by boyoh
Sat Nov 27, 2021 10:37 pm
Forum: Beginners
Topic: Trying to understand GPIO.
Replies: 7
Views: 407

Re: Trying to understand GPIO.

Olaw.jpg This is a fine example of learning to code Python .before learning Ohms Law and basic electronics. Python will tell a circuit how to work, but not build it for you or fault find, So it is back to basics for you A simple drawing of your buzzer circuit might help, to solve this problem for y...
by boyoh
Fri Nov 26, 2021 11:02 pm
Forum: Beginners
Topic: Trying to understand GPIO.
Replies: 7
Views: 407

Re: Trying to understand GPIO.

This is a fine example of learning to code Python .before learning Ohms Law and basic electronics. Python will tell a circuit how to work, but not build it for you or fault find, So it is back to basics for you A simple drawing of your buzzer circuit might help, to solve this problem for you. Regard...
by boyoh
Mon Nov 22, 2021 10:54 am
Forum: Beginners
Topic: Resister Values
Replies: 31
Views: 858

Re: Resister Values

Boyoh: Much as I admire your dedication to getting people to learn electronics, the third circuit in your notes is not safe. Winding the potentiometer to one end of the track will apply 12V directly to the transistor base -- which will result in smoke signals, but no amplification ever after. An ex...
by boyoh
Sun Nov 21, 2021 8:43 pm
Forum: Beginners
Topic: Resister Values
Replies: 31
Views: 858

Re: Resister Values

AlexMaghen wrote:
Sun Nov 21, 2021 1:08 pm
@BoyOh - 90 years?! Wow. Thanks for the advice and keep on engineering (and helping others) to at *least* age 120! :)

From BoyOh
This is part of an electronics learning curve, Build it on a breadboard, Then learn how it works.

Regards BoyOh
by boyoh
Sun Nov 21, 2021 12:01 pm
Forum: Beginners
Topic: Resister Values
Replies: 31
Views: 858

Re: Resister Values

A newbie getting his first of many RaspberryPis Is confronted by what to learn first Is It Python or Ohms Law Knowing very little about Electronics which of the two, will be of most use to him doing his first project. What good is Python to him, If he has no idea of how the project he has copied wor...
by boyoh
Fri Nov 19, 2021 11:02 am
Forum: Beginners
Topic: Resister Values
Replies: 31
Views: 858

Re: Resister Values

A basic course in electronics will be of great help to you, This will cover the use of resistors, as in Ohms Law.

Regards BoyOh
by boyoh
Thu Nov 18, 2021 11:18 am
Forum: Beginners
Topic: is there a multiple pi power system??
Replies: 7
Views: 263

Re: is there a multiple pi power system??

hi all im experimenting with raspberry pi servers but its becoming really annoying to do some things with my lots of pi's at once, like startup, shutdown and reboot, what i could do with is some sort of power system that when the master pi gives the command to startup, shutdown, or reboot it sends ...
by boyoh
Sun Nov 14, 2021 1:30 pm
Forum: Beginners
Topic: Use pico to send and recieve inputs?
Replies: 2
Views: 113

Re: Use pico to send and recieve inputs?

How can I utilize a pico in order to recieve a signal from a door sensor , like the one that adafruit has, and send power to a linear actuator to move up and down. Can I do this all in python? My vision is when I open a door, the magnetic door sensor will activate the linear actuator to go down. Wh...
by boyoh
Wed Nov 10, 2021 4:24 pm
Forum: Beginners
Topic: Turning on relay remotely using raspberry Pi GPIO
Replies: 7
Views: 228

Re: Turning on relay remotely using raspberry Pi GPIO

If your relay is in some existing circuit , then you will need some sort of interface to be able to control this relay using a pi , we would need to know a lot more about this existing circuit because what you have said about " I always connect pin 5v with the ground pin " does not make s...
by boyoh
Fri Oct 29, 2021 4:57 pm
Forum: General
Topic: Measuring Speed of Light without moving parts
Replies: 32
Views: 1587

Re: Measuring Speed of Light without moving parts

that is SIGNAL RISE TIME. I often wonder if this is one of the problems that they have encountered i think the solution to that is to just change the distance if 1 meter gives you say 120 time-units, and 2 meters gives you 220 time-units, then you can see its 100 time-units/meter, with a 20 time-un...
by boyoh
Fri Oct 29, 2021 4:33 pm
Forum: General
Topic: Measuring Speed of Light without moving parts
Replies: 32
Views: 1587

Re: Measuring Speed of Light without moving parts

I might be totally wrong in the process of measuring speeds, there is one thing you cannot cancel out. that is SIGNAL RISE TIME. I often wonder if this is one of the problems that they have encountered on the CERN EXPERIMENT, Not much on it for a long time, This is only thought on my mind Am I right...
by boyoh
Tue Oct 19, 2021 10:09 am
Forum: General discussion
Topic: Do we love the 40-pin header? Is there something more desireable?
Replies: 33
Views: 1463

Re: Do we love the 40-pin header? Is there something more desireable?

This might help with an electronics learning curve. , Making the layout is also part of the learning All built using Vero Board, Good for learning, to solder, All Pi connections and also fitted Slotted Opto Isolators for voltage leveling and signal switching, Use jumper wires from the board to the B...
by boyoh
Sun Oct 17, 2021 11:44 am
Forum: Other projects
Topic: Resistance across the 5V GPIO pins of a Pi 4 during withdrawl of power?
Replies: 12
Views: 743

Re: Resistance across the 4V GPIO pins of a Pi 4 during withdrawl of power?

Many people are building Raspberry Pi-based devices that use USB powerbanks for power. Most of these powerbanks lose power for a fraction of a second when plugged in to charge, causing the Pi to reboot. There are a few complex solutions to this, but I'm hoping to put together a simple one. Does any...
by boyoh
Sat Oct 16, 2021 3:19 pm
Forum: Beginners
Topic: Li-Ion battery power for Raspberry Pi 4 advice needed
Replies: 11
Views: 471

Re: Li-Ion battery power for Raspberry Pi 4 advice needed

Okay, you can post your schematic if you want us to take a look at it. Seems to me, that since this is a school assignment, it should be his instructor that vets his design. From BoyOh It would be an advantage to know the age of the Poster, And what level his educations are at It is not fair to the...
by boyoh
Fri Oct 15, 2021 9:46 am
Forum: Beginners
Topic: Li-Ion battery power for Raspberry Pi 4 advice needed
Replies: 11
Views: 471

Re: Li-Ion battery power for Raspberry Pi 4 advice needed

Just a word of warning, if you intend to carry on with this project, using a high current output battery You must use some overcurrent protection for each parallel load of the battery ( Fuse ) The output impedance of your battery must be LOWER than the total impedance of the total parallel loads Reg...
by boyoh
Thu Oct 14, 2021 10:56 pm
Forum: Beginners
Topic: Li-Ion battery power for Raspberry Pi 4 advice needed
Replies: 11
Views: 471

Re: Li-Ion battery power for Raspberry Pi 4 advice needed

Hi everyone, I need to power a raspberry pi 4 with a single Li-Ion battery for a senior design project. The RPI4 will have usb peripherals and other peripherals as well. I know the rated voltage and current for the RPI4 is 5V and 3A, does a 3.7V 4500mAh battery and a boost converter sound like an e...
by boyoh
Thu Oct 14, 2021 11:43 am
Forum: Beginners
Topic: CURRENT CONCERN ON RASPBERRY PI 4
Replies: 8
Views: 458

Re: CURRENT CONCERN ON RASPBERRY PI 4

This is a project that can be solved by using Ohms Law. That is if you understand the basics of electrical/electronics and apply it to your project. . As a team leader, you must understand all this. to complete this project. Ohms Law The strength of a current ( AMPS) Is directly proportional to the ...
by boyoh
Wed Oct 06, 2021 1:59 pm
Forum: Beginners
Topic: Outdoor System Advise
Replies: 10
Views: 608

Re: Outdoor System Advise

Thanks BoyOh Agreed, is on me to make it and thats the bit I am looking forward to the most. I have been producing experiential content for years but never actually developed a system myself, so in that respect it is exciting new territory. >S From BoyOh An example of your experiential content will...
by boyoh
Tue Oct 05, 2021 10:39 am
Forum: Beginners
Topic: Outdoor System Advise
Replies: 10
Views: 608

Re: Outdoor System Advise

Well you have proved to the forum you are very capable of writing about your project and talking about it but lack the ability, of understanding the electronics to carry it out, The forum will give you advice but not design it for you (Just remember if you go to the bank for a loan,, Plead Poverty )...
by boyoh
Sun Oct 03, 2021 9:59 pm
Forum: Beginners
Topic: Automatic Pill Dispenser
Replies: 5
Views: 433

Re: Automatic Pill Dispenser

I have a 7" HDMI touch screen that I would like to use.\ [7inch HDMI Display-B - LCD wiki](http://www.lcdwiki.com/7inch_HDMI_Display-B) I have a LoLin NodeMcu V3 esp32 bored. How can I use both? Can I replace EV15R70A - AVR-IoT WA (ATmega4808, WiFi, AWS) with a LoLin NodeMcu V3 esp32 bored.? c...
by boyoh
Fri Oct 01, 2021 10:35 am
Forum: Python
Topic: py project which works as in plc in continuous cycle
Replies: 4
Views: 480

Re: py project which works as in plc in continuous cycle

If your intention is to use the Pi in a PLC mode, there is a lot of rules to stick to. The PLC is very much used in industrial applications, If this is your intention, all your coding ( Ladder Diagram ) must be ( FAIL TO SAFE ) whether you are doing your project in Sequential or Combinational Logic....
by boyoh
Mon Sep 27, 2021 4:00 pm
Forum: Beginners
Topic: [Solved] Is there any current limitation while powering the Pi by GPIO?
Replies: 13
Views: 646

Re: Is there any current limitation while powering the Pi by GPIO?

What you are doing is Parraleling separate loads off one power supply, There is no problem with this, What rules you must stick to is the total load placed on the main power supply, must not exceed its maximum current output ( Impedance ) As a precaution, I would have some OVER CURRENT protection fe...
by boyoh
Thu Sep 16, 2021 12:47 pm
Forum: Beginners
Topic: Using a PI to receive a signal once the door bell is pushed
Replies: 10
Views: 445

Re: Using a PI to receive a signal once the door bell is pushed

nordpol wrote:
Wed Sep 15, 2021 4:17 pm
Thanks!
This circuit using Opto Isolators might be of use on this project. Very good at voltage leveling

and Isolation. Just keep it in mind .

Regards BoyOh
by boyoh
Mon Sep 13, 2021 7:44 pm
Forum: Beginners
Topic: Stupid questions about resistors and the Freenove Tutorial kit
Replies: 6
Views: 502

Re: Stupid questions about resistors and the Freenove Tutorial kit

You lack a very basic understanding of Electronics. Your learning curve must be at the very bottom. An understanding of building circuits,, must start with learning and applying OHMS LAW. So some good books are needed ( OHMS LAW ) The strength of a CURRENT ( amps ) Is directly proportional to the pr...

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