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RE: In regarding of stem project

kmikemoo — Wed, 23 Mar 2022 02:56:09 GMT

Kumarharsh1 STEM = Science, Technology, Engineering and Mathematics It is an acronym or a general catch-all phrase for anything involving learning and science, technology, engineering and/or mathematics.

In regarding of stem project

Kumarharsh1 — Tue, 22 Mar 2022 01:45:56 GMT

Hello, I want to know about stem project, why it is useful and where it is useful and how ???

Creating square wave generators before buying a function generation/counter

scsiraidguru — Tue, 08 Feb 2022 17:02:11 GMT

I have been watching Karen's videos and find them interesting.

My Siglent SDS1104X-E 100 Mhz 4 channel Oscilloscope came.

1.) Using the built-in square wave to calibrate the 4 probes

This took a few days to get the probes as accurate as possible.   It took about 30-45 minutes per probe.

2.) Configuring a simple 1kHz square wave PWM with my Arduino

I connected up probe 1 of the scope to the output of the Arduino PWM pin to see how accurate the device was in a square wave PWM of 0, 64, 128, 192 and 255.   I wanted to see how much noise was on the Arduino using the 9V 1A power supply.   I need to dig in deeper to get the settings to get a PWM closer to 1kHz.

https://mc.scsiraidguru.com/?page_id=2338
I posted the readouts here.   Frequency was 975 Hz.   I will recreate the test and add the measurements from the scope.

3.) Configuring a simple 1kHz square wave PWM with my Raspberry Pi 4B

The Pi 4B set to

mc.scsiraidguru.com/

pwm = GPIO.PWM(ledPin, 1000) # Set Frequency to 1 KHz    This was 886-888 Hz
pwm = GPIO.PWM(ledPin, 1149) # Set Frequency to 1 KHz    This was 997 Hz to 1.003 KHz.

4.) Purchase a 3 channel bench power supply

The next item I am looking at is the Siglent SPD3303X-E 3 channel power supply. The frequency generator will have to wait.   I The test videos I saw on this power supply was very clean.

5.) Build square wave generators that are more accurate

I have been watching Karen's videos on 555 Timer and creating a 1 kHz, 10kHz, and 100 kHz square wave generator from scratch.   I have a nice selection of resistors, capacitors, and components to build with.    I thought this would be a great project to teach STEM with.    Any suggestions on getting a more accurate setup?

5.) Create a triangle wave generator

RE: Creating square wave generators before buying a function generation/counter

scsiraidguru — Sun, 20 Feb 2022 14:39:20 GMT

10 kHz square wave. I think this is fairly good specs.

Pin 5 : 10nF capacitor

Capacitor: 10nF
R2: 4.7k ohm + 2.2k ohm+ 100 ohm= 7k ohm
R1: 330 ohm

Frequency: 9.99kHz
Period: 100.141us

+ width: 49.4us
+ duty cycle: 49.34%

– width: 50.74us
– duty cycle: 50.66%

Still working on getting Eagle up and running with a 555 timer.

RE: Creating square wave generators before buying a function generation/counter

scsiraidguru — Sat, 12 Feb 2022 20:56:28 GMT

#include <Wire.h>

void setup() {
  Serial.begin(9600);
  Wire.begin(0x4);                // join i2c bus with address #4
    pinMode(6, OUTPUT);
}

void loop() {
  analogWrite(6, 128);
 
}

set timer 0 divisor to    64 for PWM frequency of   976.56 Hz (The DEFAULT)

The measurements of the scope matches.

RE: Creating square wave generators before buying a function generation/counter

scsiraidguru — Sat, 12 Feb 2022 20:51:56 GMT

RE: Creating square wave generators before buying a function generation/counter

shabaz — Fri, 11 Feb 2022 00:17:43 GMT

Hi, I missed responding to this:

Arduino code loop was to keep it constantly running and not one time run

Sure, I understand that, however the approach to do that can be different, and it may improve the timing (can't guarantee that, since I don't know the Arduino function in detail, I've not checked the source code nor the microcontroller datasheet). In any case it's not normal to set the PWM configuration repeatedly, if the configuration has not changed.

This would be a 'normal' approach (in slightly pseudocode):

setup()
{
  analogWrite(PWM_IO, 64);
}

loop()
{
  delay(1000);
}

That code will simply do nothing in the loop() function, and do it forever. Meanwhile, the PWM hardware inside the chip will keep doing its thing (unless later instructed otherwise), based on the configuration that was done in the setup function.

I don't use Arduino often enough to be sure if this code structure will work once the syntax is sorted, but I'm fairly sure (95%).

RE: Creating square wave generators before buying a function generation/counter

shabaz — Thu, 10 Feb 2022 23:37:32 GMT

I was looking for a book on all the 555 projects I can build

There's several used 555 projects books on Amazon etc., I don't think there are any new, since the 555 is quite a mature product. However the used books are sometimes pricey because they are out-of-print. The web link to the 555 projects mentioned earlier, is very good.

I have a paperback 555 project book by E.A. Parr, it is (was) great, but the web link content is (from my perspective) better.

Many electronics books will have a section on the 555, sometimes focussed on how to use the 555, rather than projects, depending on the book. There's a thread on good electronics books here, and most will refer to the 555 for at least a few paragraphs if not more:

/members-area/personalblogs/b/john-wiltrout-s-blog/posts/i-want-to-do-electronics-where-do-i-start

RE: Creating square wave generators before buying a function generation/counter

scsiraidguru — Thu, 10 Feb 2022 14:35:11 GMT

A side project is getting LT Spice to simulate the 555 timer and my circuit accurately. During my B.EE, we put the circuit on page. Solved it with math. Then, we put it into Spice and compared the results. Last thing was acutally build it measing each component with a multimeter and recalculating everything with real values. How can I get LT Spice to better simulate a NE555?

RE: Creating square wave generators before buying a function generation/counter

scsiraidguru — Thu, 10 Feb 2022 00:07:28 GMT

The kit I bought has NE555 chips to start out with. TLC555CPWR from Digikey are $0.95. Maybe I will get some next time.

RE: Creating square wave generators before buying a function generation/counter

dougw — Wed, 09 Feb 2022 22:18:35 GMT

You can lookup several ways to make a 555 circuit that will get very close to 50% duty cycle. One simple way is to use a CMOS 555 and connect the output to the timing cap with a resistor.

RE: Creating square wave generators before buying a function generation/counter

scsiraidguru — Wed, 09 Feb 2022 21:07:30 GMT

I upgraded the scope firmware and also found the LED lights in the basement were throwing off noise that was causing the probe calibration to jump.   I put the scope into alternative mode so the end was on left side and beginning of the square wave was on the right side and was able to match them up more accurately.    I am considering a Tripp Lite Line Conditioner and put in 20A circuits to isolate the Siglent hardware from the soldering iron and other noisy components.   I worked with a Siglent engineer on getting it smoother.   The scope has some error too.   On one channel I should get 1 gigasample per second. I think with the 1 kHz frequency, that won't be much error.   It will be interesting once I get to 100 kHz frequency.   I think a lot of the scope issue was not being familiar with how to use it.

Arduino code loop was to keep it constantly running and not one time run. I am planning on revisiting the Arduino and Pi solutions for PWM.

I will have to check into your divider by 2 logic gate solution. It would be interesting to build.   The next purchase is the Siglent 3 channel power supply.   The Siglent frequency generator is month down the line.   My son's tuition for preschool is coming up in a few months.   So my EE budget is the least priority.

555 timer won't give a perfect 50% square wave.   I worked out the math for a 1 kHz frequency but the time high is 512 ms and time low is 488 ms.   This isn't that bad considering the error of 12 ms.   I played around with the common components that I have in capacitors and resistors.   Building it will be the test.   I will use my multimeter to get accurate readings on the components and redo the math.   I was hoping for 505 ms and 495 ms with 1 kHz frequency.    The new components are the sizes in between I was missing in caps and resistors. So can use the multimeter to get the components closer to the actual math values.

Scope is accurate. The resistors and capacitors are 5%-10% variance. So a 220 ohm resistor is usually 214-222 ohm.   So what is accurate on paper in the math isn't what the component is in reality.

I was looking for a book on all the 555 projects I can build.   I have a good selection of op-amps and components from this months purchase to play with.   I wanted a decent scope to start out with. All the reviews said this was a good choice.

RE: Creating square wave generators before buying a function generation/counter

shabaz — Wed, 09 Feb 2022 20:26:41 GMT

Hi,

I had a few miscellaneous comments:

(1) There's something unusual in the code, there is a loop containing analogWrite, and it will repeatedly try to execute it forever.

This may or may not be benign, and may even contribute to measured discrepancy or even jitter. It is down to the implementation of that analogWrite function, I have not checked, but it would be good to either check it before doing this, or (better) just do it in the setup() function, because that will be a more normal use of it. Often, functions can misbehave if used beyond what they were likely designed and tested for.

(2) The measurements from 'scopes are not necessarily accurate always. Despite it being (say) a 100 MHz 'scope, doesn't mean it is sampling with that granularity always, and it will also have it's own clock error too.

(3) The probe compensation should take less than a minute per probe and per channel, even if doing it manually. If it's not automated, then the probe should have a trimming tool adjustment.

(4) Not sure what you mean by a more accurate square wave, because the '555 output will almost certainly be less accurate than from the 'scope; the frequency will drift with temperature, and it's not a square wave anyway... I think from memory the 555 cannot generate a 50% duty cycle precisely due to the charge or discharge cycle having to use the same resistor (along with another), I have not checked in ages. One workaround for that is to do a divide-by-2 using logic gates, from the output of the 555 or whatever.

(5) STEM with 555 is a great idea.. for instance using it to generate sound effects and so on. Combining more than one 555 allows you to do siren-type effects, etc. There's a very good website with 50 projects entirely related to 555: http://talkingelectronics.com/projects/50%20-%20555%20Circuits/50%20-%20555%20Circuits.html?iframe=true&width=100%&height=100%

My code include fast calculation and response and saving data so as a controller arduino is capable or have to use it along with Matlab simulink

nikhilchotai — Sun, 20 Nov 2016 14:37:56 GMT

As i am controlling solenoid operated pneumatic valve along with pressure sensor and using rotary encoder as my code include calculation part, Now along with control part i want to save data or record data also so what will be better to use arduino only or have to use arduino with MATLAB simulink

domotic aplications for rasperry

Former Member — Sun, 19 Jun 2016 23:34:14 GMT

I would like to know if someone designed appplications for domotic

Quick talk on last year's design challenge

Workshopshed — Wed, 03 Feb 2016 10:43:50 GMT

I've been invited to talk to the London Arduino meetup, about the Enchanted Cottage project where I took a traditional weather house and filled it full of electronics and 3D printed mechanical parts. The plan is to talk about how I went about the design challenge and leave any technical questions for the informal session afterwards.

It's on February 17th in the City of London.

[View:/resized-image/__size/291x320/__key/communityserver-discussions-components-files/202/1581.contentimage_5F00_66619.jpg:291:320]

http://www.meetup.com/LondonArduino/events/228396793/

Also talking with

• Michael Margolis - Create a connected project with the ESP8266 module

• John Nussey - Developing a connected product: the story of the Ding Smart Doorbell

RE: Quick talk on last year's design challenge

Workshopshed — Thu, 18 Feb 2016 17:56:21 GMT

Thanks Clem, the house went down well with the ladies who attended 5381.contentimage_1.png

RE: Quick talk on last year's design challenge

Workshopshed — Thu, 18 Feb 2016 17:55:58 GMT

An overview of the evening with some of the other projects and talks

https://storify.com/londonarduino/connected-products-london-arduino-meetup

RE: Quick talk on last year's design challenge

clem57 — Thu, 18 Feb 2016 16:28:11 GMT

I still think this is the best of the projects on E14. Sorry the others are good but not as cute!

Clem

RE: Quick talk on last year's design challenge

Workshopshed — Thu, 18 Feb 2016 14:36:37 GMT

{gallery} Photos from the evening
7853.contentimage_180797.jpg Getting ready: The Enchanted Cottage survived the trip
3644.contentimage_180798.jpg Intro: Explaining the design challenge
5710.contentimage_180799.jpg How it works: A bit about how the cottage mechanism and electronics work
1581.contentimage_180800.jpg Live Demo: The internet part was mocked up so we got different weather each time
3666.contentimage_180801.jpg Show and Tell: After the talk the attendees had a chance to see the cottage close up

{gallery} Photos from the evening

7853.contentimage_180797.jpg

Getting ready: The Enchanted Cottage survived the trip

3644.contentimage_180798.jpg

Intro: Explaining the design challenge

5710.contentimage_180799.jpg

How it works: A bit about how the cottage mechanism and electronics work

1581.contentimage_180800.jpg

Live Demo: The internet part was mocked up so we got different weather each time

3666.contentimage_180801.jpg

Show and Tell: After the talk the attendees had a chance to see the cottage close up

Video of the talk https://skillsmatter.com/skillscasts/7540-miniature-iot-enabled-cottage-winning-project-design-challenge-element14#video

and slides https://drive.google.com/file/d/0ByAK8iN19l4OZWx1U3lQOElsLUU/view?usp=sharing

The https://twitter.com/AtmelAtmel SAMA5D4 Xplained Ultra was won by Brian https://twitter.com/BrianLinuxing who correctly provided an explanation of the "Yocto Project" and he looks forward to getting Linux to run on the board and cross compiling applications.

RE: Quick talk on last year's design challenge

Workshopshed — Thu, 04 Feb 2016 06:56:49 GMT

I am not sure that usually happens but I'll check with the organiser.

RE: Quick talk on last year's design challenge

mconners — Wed, 03 Feb 2016 21:33:55 GMT

Yeah, that would be nice.

Mike

RE: Quick talk on last year's design challenge

Jan Cumps — Wed, 03 Feb 2016 21:32:35 GMT

Are they going to film your talk and youtubise it?

RE: Quick talk on last year's design challenge

clem57 — Wed, 03 Feb 2016 14:53:51 GMT

Quite the celebrity you are. But you deserve it. Let us know what is on the mind o the people there.

Ty,

Clem

RE: Quick talk on last year's design challenge

Workshopshed — Wed, 03 Feb 2016 12:00:28 GMT

The new Hans and Matilda are getting ready 38608.contentimage_1.png

Hans and Matilda's trip to the USA