Tag Archives: programming

Jul 17

DS Programming – Messing with basic sound

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The second program I made was to test some basic sound functionality. I basically have the DS play a sinewave. The panning can be influenced by moving left or right on the touchscreen, the frequency by moving up or down. Hit the A button to toggle sound on/off. Using the L and R shoulder buttons you can change the dutycycle of the wave.

As always, here’s the code if you would like to give it a try:

#include <stdio.h>
#include <nds.h>
#include <nds/ndstypes.h>
 
int sound = 0;
int sndStatus = 0;
touchPosition TouchStructure;
u16 Pressed;
u16 Held;
u16 Released;
const int FREQ_MUL = 100;
const int VOLUME = 64;
//---------------------------------------------------------------------------------
int main(void) {
//---------------------------------------------------------------------------------
	int xPos = 120;
	int yPos = 40;
	int span = 64;
	int duty = 50;
	consoleDemoInit();
	soundEnable();
	sound = soundPlayPSG(duty,yPos * FREQ_MUL,VOLUME,span);	
	soundPause(sound);
	while(1) 
	{
		swiWaitForVBlank();
 
		scanKeys();
		Pressed = keysDown();
		Held = keysHeld();
		Released = keysUp();
 
		touchRead(&TouchStructure);
		if(TouchStructure.px > 0)
		{
			xPos = TouchStructure.px;
			span = div32(xPos, 2);
			soundSetPan(sound, span);
			iprintf("xPos: %d - pan: %d\n", xPos, span);
		}
		if(TouchStructure.py > 0)
		{
			yPos = TouchStructure.py;
			iprintf("yPos: %d\n", yPos);
		}
 
		if(KEY_A & Pressed && sndStatus == 0)
		{
			soundResume(sound);
			sndStatus = 1;
			iprintf("Sound On\n");
		}
		else if(KEY_A & Pressed && sndStatus == 1)
		{
			soundPause(sound);
			sndStatus = 0;
			iprintf("Sound OFF\n");
		}
 
		soundSetFreq(sound, yPos * FREQ_MUL);
 
		if(KEY_L & Pressed)
			if(duty >= 5)
				duty -= 5;
		if(KEY_R & Pressed)
			if(duty <= 95)
				duty += 5;
 
		soundSetWaveDuty(sound, duty);
 
		if(KEY_B & Pressed)
			iprintf("Freq is %d, pan is %d, duty is%d\n", yPos, span, duty);		
	}
}

Note that for the panning variable I used span, initially I used ‘pan’ but for some reason that didn’t work as pan was always 0 whatever I did with it. I also wasn’t really sure how to have the A button toggle the sound, I didn’t find a function that grabs the status whether the sound is on or off so I added my own variable to keep track of it.

Also notice my FREQ_MUL, as I did with the panning conversion, I added a multiplier since I’m using the y-values of the touching on the screen. Since the screen is only about 200 pixels in height it would be no fun to just have frequencies ranging from 1 to 200 Hz.

It’s really amazing how easy it is to make basic applications that work on the DS thanks to libnds and DevKitPRO. I wonder if it has surpassed the official Nintendo SDK in usefulness after all these years of improving it. It really is a sad thing all of these official SDKs aren’t available for the masses.

The next thing I’m going to give a try is something with graphics. NightFox’s graphics library seems to be quite nice for beginning developers. Thanks to the Grit application converting bitmap files into supported files that the NDS can display is a breeze.

Jul 16

Nintendo DS Programming

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I was just learning some C++ syntax the other day and figured I should give Nintendo DS programming a go since I’ve got a flashcard and it’s always fun to see your result on an actual device instead of an emulator.

I started out with a guide on GBAtemp which, although pretty limited at the moment, gives you enough info to get some basics done. User input checking (both touchscreen and buttons) and displaying a simple message is always a fun way to get started with things. Here’s the code I wrote:

#include <nds.h>
#include <stdio.h>
 
u16 Pressed;
u16 Held;
u16 Released;
 
touchPosition TouchStructure;
//---------------------------------------------------------------------------------
int main(void) {
//---------------------------------------------------------------------------------
	consoleDemoInit();
	iprintf("Hello World!\n\n");
	while(1) 
	{
		scanKeys();
		Pressed = keysDown();
		Held = keysHeld();
		Released = keysUp();
 
		touchRead(&TouchStructure);
		int xPos = TouchStructure.px;
		int yPos = TouchStructure.py;
		if(xPos > 0 || yPos > 0)
			iprintf("Position of touch is (%d, %d)\n", xPos, yPos);
 
		if(KEY_A & Pressed)
			iprintf("You pressed the A button!\n");
 
		swiWaitForVBlank();
	}
 
}

This code snippet will display a classic Hello World along with some info whether you pushed the A button or tapped the touchscreen somewhere.

It’s not much but I’ve just got started with it, let’s see how far I get!

Mar 02

Another password idea

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As I was biking to my C programming class this morning this suddenly popped into my head: “what if you just use an easy to remember programming statement as a password for an account?”.

Of course, this only works if you have a couple of statements you regularly use (which aren’t 100% textbook examples) but still, an interesting idea. Basically, an example for a gmail account password could be:

for(inti=0;i<gmail;i++)

I’d love to see a brute force attack getting this password. In the end, even a novice programmer knows such a simple statement as a for loop, and a whole lot of variations are possible as well. If you’re not too keen on those password programs and can’t remember something like ‘KfjE@JZ9I$47lo’ this is yet another way to make sure your password is pretty strong and easy to remember and customize for each website.

If you have clever ways to come up with a password, feel free to let me know in the comments.