physicalcomputingblog-blog1

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Week 12 of Physical Computing

My little brother is hands down amazing. 

I’d sought out his help at the advise of mum to provide a second set of eyes to look over the circuitry, he’d only ever programmed in Python and C++ before, but he could figure out the booklet enough to spot something that I’d completely missed because I hadn’t identified it as wrong. 

The black line for the motor was plugged into the wrong part of the transistor. 

Causing the power coming in from the plug to completely bypass the need for a digital input, and sending all the power coming into the Arduino board right into the fan motor.

At some point after I’d knocked the wires for the motors out of the bread board, I’d accidentally put the black wire back into the board one row over, negating it completely from its intended role. 

Once that was remedied, we, plugged the board in, nothing happened, the fan didn’t spin up to full force instantly, then I uploaded the code, and proceeded to try not to cry, because again, nothing happened, until I pressed the button.

As shown in the video below, it worked, it worked perfectly!

It’s a bit different from how I’d originally planned to have this operate, but it worked!

And here’s the code that runs is all. 

So yeah, despite Corvid-19, and a horrible case of Gastroenteritis, I managed to finish in time! 

Sure it’s probably nowhere near as advanced as some of my coursemates, but I’m happy with what I’ve been able to pull off with what I’ve had available. 

Thank you for taking the time to read this all, - Katherine Marshall 349037

(I’m going to post the links to all the videos I’ve made during this in the document I’m going to submit to Turnitin.)

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Week 11 of Physical Computing

I haven’t been able to figure it out, I’ve been checking, and re-checking the code throughout the last week when I have the time, my other projects also need my attention so I haven’t been able to dedicate as much time as I’d like to fixing this problem. 

The fan still runs absurdly fast from the moment it’s plugged in, the button does nothing, and the seven segment display gave one pulse of all the segments lighting up once when I plugged it into the board, but I’d hardly count that a victory. 

I’ve messaged my professor asking if he’d be able to provide a second pair of eyes to this problem, hopefully we’ll be able to figure out what’s gone wrong. The deadline is coming in fast now and I’m starting to panic a bit, not gonna lie there, this has been way more stressful than I ever wanted it to be. 

-Intermission-

Alright, so the code I found on Arduino for the button was unnecessarily over complicated for what I needed to do, I’d ended up formatting it all rather shoddily in the process of trying to implement it into the rest of the code, sir was able to work through everything that needed to be remedied with me over a video call.

So the code should all be working now, sir said it should work just fine, we ended up making it so that, at the press of the button, the void loop containing the seven segment display count down, and the fan motor running will activate, run its course, and then stop again, waiting for the next input from the button. 

-Intermission-

The fan’s still running without hesitation, it’s not the code, it’s something in the actual physical circuitry that’s wrong. 

But I’ve taxed out my brain enough already today, so I’m going to stop here and try and figure out what’s gone wrong tomorrow. Hopefully I’ll discover what’s wrong once I’ve rested and had time to get some of this stress out of my head. 

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Week 10 of Physical Computing

Okay, so the code is written, but I’m not having much luck with getting it to work, I know there’s stuff that’s wrong with how I’ve laid it out, and I’ve probably shot myself in the foot a bit by just diving head first into this.

The phototransistor has been replaced by a button now, I was able to find a code example on Arduino’s website that is for a button that sends a signal that activates the rest of a code if pressed once, and then turns off the circuit after the button is pressed a second time.

Implementing said code has proven a bit on the tricky side, but it’s all been added now.

Now to give it a test run.

-Intermission-

I feel like I’m the butt of a joke… The fan, the moment I plugged in the board to test the button, the fan just shot up to maximum revolutions and didn’t stop until I unplugged the board again over four minutes later. 

Sods law, anything that can go wrong, will go wrong. It’s a saying my family lives by… and it’s gone and come to fruition at the worst of times. 

Maybe something in the code is causing it to bypass everything and just run infinitely?

That shouldn’t be happening, but it looks like I’m going have to do quite a bit of investigating to figure out what’s gone wrong. 

Can’t really make progress on getting the button to work until the fan’s fixed.

Oh and the seven segment display, which I've coded to run before the fan now, as a countdown to when the fan turns on, isn’t running at all either, so somethings gone wrong there.

Everything’s gone wrong, here’s hoping I’ll be able to figure this out. 

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Week 9 of Physical Computing

Alright, so, I’m fairly set on what I want to make now. 

I want to create a circuit, that is completed by a hand wave over a photo transistor. With the circuit completed, the fan motor will activate, run its course for a time, before the seven segment display begins a countdown to when the fan will stop running. 

Setting it all up wasn’t too hard, considering I’d left the seven segment display circuit, and the fan motor circuit all plugged in a ready to go from the last two weeks, never really felt like taking it all apart when I had a fairly good idea I’d be wanting to use them both in my final project. 

The only physical addition to make was to add the photo transistor to the bread board.  

Now, I just have to write up the code so the motor and countdown run after the phototransistor completes it’s circuit and sends the input pulse to trigger everything else. The picture above was taken before I started work on the code, when I ran the seven segment display’s code again because it was a lot of fun to watch it just tick up and down from zero to nine and back down to zero.

-Intermission -

Okay so slight hiccup, because of how many cables are above the phototransistor, there isn’t really room for my hand to pass over it close enough to cut the light enough for the phototransistor to pick up, there’s a clearance of about three/four inches between the phototransistor and where my hand can go without hitting any of the wires.

So, because the phototransistor is proving to be an unnecessary hassle, I’ve decided to replace it with a button switch instead.

I’ll do that once I figure out why the motor is being so spotty sometimes.

I’ve discovered that, after a couple times of running the fan motor to stress test it, more for my own reassurance that I’m not imagining the fact that it’s working, the motor will sometimes just stop running early. I’m suspecting a dodgy connection somewhere in the circuit. I’ll ask the professor about it during the 1-2-1 session later and see if we can figure out where the problem might be, very much hoping it isn’t the motor itself that might have a manufacturing fault to it. 

-Intermission- 

We got the culprit, the terminal connector has circular holes to put the wires into, but the tabs that screw down to hold the wires in place are flat, meaning there’s a gap left behind that the very thin ends of the wires can slip out of over time due to the vibrations caused by the motor.

I’ve opted to bypass the terminal connector and just push the motor wires directly into the bread board, it’s certainly more space efficient, the terminal connector, when plugged in covered over eight slots for the use of just two. 

As seen there, even with the terminal connector out of the picture, the fan now runs perfectly fine with the motors wires plugged directly into the bread board. 

I just have to be careful not to knock those two wires out, they’re quite fiddly and my finger nails are certainly not best suited to carefully picking them up to put them back into place.

Oh well, that’s what make-up tweezers are for right?

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Week 8 of Physical Computing

Did a couple more experiments to work up my confidence this week, and then set to work on trying to pull together an idea for the final project. With all the delays caused by me being sick, and Amazon being impossible to use, story of that mess at the end of this post, I’m well aware I’m well behind on this, so I had to make do with what I had to offer, which can be summed up as one Arduino supporting ‘Inventors Kit’. 

I’ve decided I want to make something that uses both the fan motor, and a seven segment display that came with the kit. Now it’s only one seven segment display so the most I can really do is say, have it count up from zero to nine, or count down from nine to zero. 

So, with the looming fact that I’m behind by three weeks looming over my head, I’m gonna dive right in and pray really hard this all works. 

-Intermission-

(After some help from the Professor) It works! Currently I have it so it counts up from zero to nine, then back down again to zero, before looping and starting the cycle all over again.

This was the longest code I’ve had to write in quite a long time, but I’m really happy that I managed to get it to work!

I’ll admit when I first tested it out, I discovered I’d muffed the nine and six’s binary, but those were easy enough to fix. Nine was missing the center light and six ended up as a zero with the top missing. 

Like the week before, I made a little circuit diagram to help me understand how I’d set up the seven segment so I wouldn’t have to get turned around by all the overlapping wires I now had covering a good chunk of my breadboard and Arduino. 

And now for the amazon story.

Back in October, I tried to buy a replacement charger for my laptop, after the old one got broken while I was having to move seats on a train from London Paddington to Bath. So, knowing my laptop wasn’t going to get another charge any time soon, and with it already at 40% battery, I set up an account on Amazon, and hunted down a replacement charger that would work for my laptops model, it’s a ASUS so their replacement chargers are a bit harder to get than say, an Apple laptops. 

I spend the £40 odd pounds, Amazon confirms that the order has been received.

And then Amazon locked my brand new account for ‘suspicious activity’. 

A notification on the page said they had sent an email to me to get the account unlocked, but no email ever appeared, in my inbox, spam folder, on anywhere else in my Gmail. 

So I tried to contact their support number.

Unfortunately I was wearing headphones at the time, and the ungodly blast of white noise that I was subjected to before the line went dead was very unpleasant. 

I can confirm, after trying to get by account unlocked again, in a time where I would definitely benefit from being able to purchase equipment that might be able to bolster the tiny amount I have available, that the white noise followed by the line going dead, is still the state that Amazons contact us support number results in. 

I’ve looked into other websites that offer parts I’m interested in, such as male to female jumper cables, but they only seem to provide the parts to the Continental United States unless I wanted to pay an exorbitant international shipping fee pushing three times the cost of the original items I wanted. 

At this point I can’t really afford to have any more time wasted, so I’m just going to crack on a see what I can make with just the kit I’ve got, a chimera of different experiments is probably what it’s going to end up being. 

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Week 7 of Physical Computing

The kit finally arrived this morning, just an hour before the days lecture, still unpacking the kit and trying to figure out what all the components are and do as the lecture progresses. 

The kit and tutorial book, which I have a feeling is going to be a life saver. 

First order of business, figure out how things work by trying out some of the experiments in the leaflet that came with the kit. 

First experiment is simple enough, but a good place to start after three weeks of not being able to do much at all. 

(Forgot to get a picture of the LED actually lighting up. And ignore the fan motor, that’s for a later.)

A simple button experiment, wherein, at the press of a button, an LED will light up, and then promptly turn back off when pressure on the button is removed.

Second experiment I tried out was one that used both a photo transistor sensor and analog inputs. 

A photo transistor is a transistor that reacts to light by changing how well it conducts electricity, the more photons that hit the photo transistor, the better it is able to conduct electricity. 

With this experiment the photo transistor acts as the switch that breaks of completes the circuit, if enough light hits it, it will finish the circuit and cause the little light on the side of the inputs on the Arduino board to light up. 

Here’s the code I wrote following the instructions in the leaflet. The original recommended percentage of scale for the light level was 200, but upon uploading it to the board, I found that the amount of light that needed to be produced to break the circuit, I could really only produce with the flash of my phone camera, which was rather beneficial to showing it off. 

With the flash

Without the flash

Final experiment of the week, getting the fan motor going with the help of a transistor. 

To quote the booklet on transistors -

‘The output pins on most microprocessors can only supply a small amount of current, not enough for a power hungry device such as a motor. The Arduino is no exception to this. A transistor can be used to solve this problem. A transistor is like a gate for electricity, a small amount of current can be used to open the gate to let a lot of current flow through to power hungry components. ‘

One of the other components that this circuit requires is a terminal connector, which acts as an anchoring point for the red and black wires that come out of the motor. By having the motor wires screwed into place inside the terminal connector, and the connector in turn plugged into the bread board, the much smaller wires won’t have the issue of being knockout of place, breaking the circuits connections and caused the motor to cease it’s function until the wires are put back in place. 

This is the code I wrote up to operate the fan motor. It’s set up so that the motor will loop in it’s activation and deactivation cycle from the moment the arduino board is plugged in until it’s unplugged again. The ‘OutputValue’ is in reference to how much power is going into the motor, the above code has the motors output value increased from 0 to 255, it’s maximum, over the course of 50 milliseconds. Then after 500 milliseconds, it reverses and drops from 255 to 0. I’ve discovered that this little fan motor is rather potent, and produces a nice cool breeze

Once I was sure everything was working, I decided to take the time to try my hand at some circuit diagrams of the experiments I’d run this week, and after a few test drawings in a note pad, I was fairly confident that the below are accurate to the experiments I ran.

Apologies if the motor circuit diagram is a bit saturated, it was rather late when I took the picture and the low lighting in my room meant I had to use the flash.

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Week 6 of Physical Computing

Brought up my concern that I had no physical computing equipment of any sort at home during my first online lecture, as I had left the box I was given in Bath, the professor informed as to where I could purchase an arduino kit and have it delivered to home, it wouldn’t be the same as the stuff I had in Bath in all likely hood, but it’s gonna have to do because I can’t exactly go all the way to bath now for a box of physical computing equipment. 

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Week 5 of Physical Computing

Went home to for the weekend to visit family (Did not take the equipment with me because there wasn’t room for it in my rucksack along with all the personal stuff I had packed for the weekend visit, also didn’t want something getting damaged on the way and having to pay for it.), came down with a 10 day case of Gastroenteritis (bacterial infection of the gut version), missing the last in person lectures of the year as Bath Spa announced it would be putting all of it’s lessons online from the week after because of Coronavirus. Writing this post in past tense because I was not well enough to write this one at the time. 

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Week 4 of Physical Computing

This is a code I wrote that powered a small step motor, it was supposed to rotate in one direction, then the other, but instead the motor would only turn clockwise, pause for a moment, then continue it’s clockwork rotation, I plan to trying and figure out the issue with the code on Monday when I pick up my equipment again, having decided to leave the case in Bath while I took the train from Bath to London, and then on to my home in Kent.

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Week 3 of Physical Computing

This week we worked with resistance sensors, by the end of the lecture I was able to write this code line that allowed for the control of the rate in which a LED would flash on and off, the lowest time difference being 20 milliseconds, and the highest being 1,000 milliseconds, which equates to one second. The rate of which was controlled by a small resistor, which when turned, would increase or decrease the sensorValue, which in turn controlled the rate in which the LED activated.

The other part of the lecture was us witnessing one of the professors own creations, a machine able to translate the hard lines of an image into a rough rendering on paper using a number of servos that acted independently to alter the position of a single point between them.

Caught the LED mid flash

It was a rather bright LED I ended up using, burned some blurry spots into my retina for my troubles. 

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Week 2 of Physical Computing

Joined the module, I was provided with the basic set and had my first crack at physical computing with a simple ‘Blink’ function.

The small LED light is programmed to turn on and off once every 1000 milliseconds.

The code being used. - 

// the setup function runs once when you press reset or power the board

void setup() {

  // initialize digital pin LED_BUILTIN as an output.

  pinMode(13);

}

// the loop function runs over and over again forever

void loop() {

  digitalWrite(13);   // turn the LED on (HIGH is the voltage level)

  delay(1000);                       // wait for a second

  digitalWrite(13);    // turn the LED off by making the voltage LOW

  delay(1000);                       // wait for a second

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Week 1 of Physical Computing

I haven’t joined the module yet, I opted to switch to Physical Computing after discovering that the description of the module I’d picked for this term hadn’t specified the module requirements needed for it, which I had none of.  Lee suggested I take Physical Computing instead because it was much more suited to my learning style, and didn’t have requirements of previous modules.