Untitled

Why not eh? (Note the very fitting choice of book ;p)

The code is quite clunky but it looks like this:

// --------------------------------------------------------------------------- //This is a sketch which develops the NewPing with the range sensor and the arduino tone function for an 'air keyboard' in the key of C, starting with C4. //(code is reasonably long and clunky until I figure out how to simplify it!) //pitches.h includes a library for tuned frequencies for the tone generator

#include <NewPing.h> #include <pitches.h>

#define TRIGGER_PIN  8  // Arduino pin tied to trigger pin on the ultrasonic sensor. #define ECHO_PIN     7  // Arduino pin tied to echo pin on the ultrasonic sensor. #define MAX_DISTANCE 500 // Maximum distance we want to ping for (in centimeters). Maximum sensor distance is rated at 400-500cm.

NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE); // NewPing setup of pins and maximum distance.

int note1 = NOTE_C4;

int note2 = NOTE_D4;

int note3 = NOTE_E4;

int note4 = NOTE_F4;

int note5 = NOTE_G4;

int note6 = NOTE_A4;

int note7 = NOTE_B4;

int note8 = NOTE_C5;

void setup() {  Serial.begin(115200); }

void loop(){ {  delay(50);                     // Wait 50ms between pings (about 20 pings/sec). 29ms should be the shortest delay between pings.  Serial.print("Ping: ");  Serial.print(sonar.ping_cm()); // Send ping, get distance in cm and print result (0 = outside set distance range)  Serial.println("cm"); }

Got a little bit further with the range sensor and tone - managed to sort out a compiling error by editing one of the libraries for ‘New.ping’ (so that I can actually use this library), and I’ve included the tone library for accurate pitched notes. Still trying to figure out why the ‘if’ and ‘else’ arguments don’t work as I’d like i.e. it’s not as simple as ‘put my hand here and this note plays, move it away and it stops. I’ve a feeling this is to do with the data received from the sensor and the frequency of received data. I’m still playing around with the delay to see if this helps.

One is that is you order components from overseas (i.e. China), then it may take months to arrive. The wireless modules I ordered have still not arrived since ordering them at the end of April...

The second is really just a small problem which I have yet to figure out a solution to. The ultrasonic range sensor seems to not like being powered by 9V battery, so I’m wondering how those robots get around the problem. A quick google search is probably all it will take but it’s something which I’ll need to figure out if I’m going to make a portable wireless device.

10/04/17

Task today was to extend the range sensors 'functionality' by adding two more LEDs that will light up at different ranges. In this instance, one which will light up at 0 - 10cm; the second at 10 - 50cm and the third at 50cm+. To do this I had to use my first 'and' argument, or '&&' in the arduino language. It took a little bit of verifying within the arduino console to figure out how I'd done it wrong originally, but I looked back over some of the examples in the ‘getting started with arduino’  book and it was fairly simple to fix. I needed to add the '&&' on it's own line and also be within the overall brackets of the original 'if' argument. Before this though I'd added two more LEDs as 'const int', but then forgotten to add them as outputs in the 'void_setup'; this was also easily rectifiable once my sluggish brain had realised what I'd done wrong! Anyway, the compiler now says everything is OK, but I will now move on to wire it all up and see if it works as expected...

Success!

The ranges seem to work and I’ve tested with a ruler. There does seem to be a little confusion with the 'pings' in that they seem to react a tad sporadically, though this is perhaps due to the arc of the pings and accuracy at distance generally - for example an object does not need to be directly in front of the sensor to get a reaction. I've added a delay in the code  to see if this helps. I'm also wondering if this surface which reflects the 'ping' has an effect - for example the indicating LED flashes seem much more consistent with a book than with my hand.   The ranges I've chosen at this stage are fairly arbitrary, if I was going to eventually create a device which would be installed in a corridor or a street for example, I’d want to set the range to be longer. Tests with me walking away from the sensor seem to yield readings up to 300cm or so; the maximum range is reported to be 400 - 500cm but I’ve yet to be able to get any readings from that far away. This may be something which could be improved upon by altering the behaviour of the sensor within the arduino code. I’m going to check with the original wiki.

Anyway, here is the test video:

Eventually, I’d like to build a device that can measure speed and communicate data wireless-ly, but let’s take things one step at a time.

One of the sensors which came with my arduino kit is an ‘ultrasonic range finder’, basically it sends out an ultrasonic ‘ping’ which then bounces back and tells you (via arduino) how far away objects passing in front of it are. This one has a maximum distance of five metres. 

I had no idea really how to set this thing up, but a quick google search of the sensor led me to an ‘instructables’ page here (again, testament to the wonderfully helpful and sharing nature of the open source community). I can see that I’ll probably be turning to this site for advice quite a lot!

So, new arduino library installed, sensor set up on the bread board, run some of the example code and viola! The sensor is telling my serial port how far away my hand is. 

What next then? Well, I’m thinking about my initial idea, so ideally I want to tell the arduino to do stuff based on how far away something is. As is often the case I’m finding,  probably to get and LED to light up is a good first step!

But how do I do this? Well, by this point I’ve been introduced to ‘if’ and ‘else’ arguments withing the programming language of arduino, so maybe it could just be as simple as telling the arduino, ‘if the sensor detects something at thirty centimetres or less then light up this LED, or else switch the LED off’.

Turns out it was as simple as that, it just took a while to find exactly white previous identifier in the code I wanted to if to refer to.

In the end it looked like this: 

void loop(){ {  delay(50);                     // Wait 50ms between pings (about 20 pings/sec). 29ms should be the shortest delay between pings.  Serial.print("Ping: ");  Serial.print(sonar.ping_cm()); // Send ping, get distance in cm and print result (0 = outside set distance range)  Serial.println("cm"); }

if (sonar.ping_cm() <= 30){  analogWrite(LED, i);  Serial.println("too close!"); } else {  analogWrite(LED, i - 100);}    }

The bit that I wrote is in bold. Hurrah! My first successful ‘if’ argument. Even with the cheeky addition of sending a message to the serial monitor.

This is how the finished thing looked:

Of course, I had to double check that it was all working how I’d told it to, so out came the ruler:

 Quite hard to see in this picture, but over 30cm, no light!

Now we’re ‘too close’ and the LED is lighting up and the buzzer is buzzing. Lovely. All being confirmed by the data coming into the serial monitor:

What next then? Well, two things, I think. firstly, to add some complexity I need to figure out how to get arduino to do different things based on multiple ‘if’ arguments; for example get a red LED to turn on at 30cm, a yellow one to turn on at 40cm and a green one to turn on at 50cm. Or even take the communication further and see if I can get arduino to talk to MAX or a Pure Data programme...the possibilities! (I will also need to learn how to use these programmes, of course)

I first heard about arduino through my brother - he had done a module on it during his Ba and some friends of his had built an arduino powered MIDI foot switch as part of their final project. That was a few years ago but it had always been something which had intrigued me - what is this magical device and how can I, as an artist, make use of it? 

On a bit of a whim, I’d started having a go at learning Python through code academy, but being the sophisticated programming language that it is, it seemed that I’d need to invest a lot of time learning the very basics before getting anywhere, also I was feeling impatient - I wanted to make stuff, I just wasn’t sure what yet. I’d been having ideas about using sensors to gather data which could then be translated into light/sound/something, but using such a complex language to achieve this seemed a long way off.

It was then that I remembered about arduino, I had a look at the website and some of the projects that had been built with it and felt very excited - here was a device aimed specifically at makers, musicians and artists - essentially exactly what I’d been looking for. 

So this is the first time I’ve used a blog possibly since the first year of my Ba, back in 2008. My how the best part of a decade goes fast! Anyway, before going on to making a website proper, I figured I would start writing a blog to document my ‘artistic’ endeavours, and seeing as the new direction I am taking as an artist is concerned much more with the digital and open-source world, it seems to make sense to share my progress/ experiments/ thoughts/ discoveries etc., even if it is just to blog-echo-chamber for the time being...

Background

Since graduating with a Ba in Fine Art in Cardiff in 2010 I have maintained an artistic practice on and off with varying degrees of productivity. I stuck around in Cardiff in my native Wales for a few years after graduating, supporting myself with a painfully low paid bar job (such is the destiny of many a creative graduate), but I was lucky enough to get involved with a local artist led studio space, B I T, formed by a lovely (and far better organised) set of chaps who had graduated just a year after me fro the (now infamous?) Cardiff School of Art & Design. Sadly it looks as though B I T has since dissolved but through them I was able to secure a cheap studio space where I could continue making paintings after a fairly lengthy hiatus; as well as being able to participate in their various DIY artist talks and group exhibitions. 

At the time I was working mainly with analogue photography and oil painting, making semi-figurative/abstract creations. However, in 2014, having only been with the studio for less than a year, I decided I’d had enough of Cardiff and decided on a whim one sunny earlier August afternoon to bugger off to London, encouraged in now small part by the nudging-s of a fellow Welshman and friend who had been living in New Cross for a few years.