Controlling an RC car with a TI-99

[Videogamecollector123]

So I made a post about this a while ago and thought I'd give a bit of an update. I actually got it working, as you can see in this quick video I made. I basically combined these two articles about arduino programs, one for frequency detection and another for controlling the car. I'll provide the complete code below, but it takes in the frequency from the Ti-99 audio and triggers the command to run the car forward. The audio from the Ti-99 is filtered through a circuit described in this article. Currently the code's only set up to make the car go forward, but the other directions can be added.

You'll also need this library for this code to work

#include <DigitalPin.h>

//sine wave freq detection with 38.5kHz sampling rate and interrupts

//by Amanda Ghassaei

//http://www.instructables.com/id/Arduino-Frequency-Detection/

//July 2012

/*

* This program is free software; you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation; either version 3 of the License, or

* (at your option) any later version.

*

*/

//create the forward object to make the car move

DigitalPin forward(;

DigitalPin backward(9);

//clipping indicator variables

boolean clipping = 0;

//data storage variables

byte newData = 0;

byte prevData = 0;

//freq variables

unsigned int timer = 0;//counts period of wave

unsigned int period;

int frequency;

void setup(){

Serial.begin(9600);

pinMode(13,OUTPUT);//led indicator pin

cli();//diable interrupts

//set up continuous sampling of analog pin 0

//clear ADCSRA and ADCSRB registers

ADCSRA = 0;

ADCSRB = 0;

ADMUX |= (1 << REFS0); //set reference voltage

ADMUX |= (1 << ADLAR); //left align the ADC value- so we can read highest 8 bits from ADCH register only

ADCSRA |= (1 << ADPS2) | (1 << ADPS0); //set ADC clock with 32 prescaler- 16mHz/32=500kHz

ADCSRA |= (1 << ADATE); //enabble auto trigger

ADCSRA |= (1 << ADIE); //enable interrupts when measurement complete

ADCSRA |= (1 << ADEN); //enable ADC

ADCSRA |= (1 << ADSC); //start ADC measurements

sei();//enable interrupts

}

ISR(ADC_vect) {//when new ADC value ready

prevData = newData;//store previous value

newData = ADCH;//get value from A0

if (prevData < 127 && newData >=127){//if increasing and crossing midpoint

period = timer;//get period

timer = 0;//reset timer

}

if (newData == 0 || newData == 1023){//if clipping

PORTB |= B00100000;//set pin 13 high- turn on clipping indicator led

clipping = 1;//currently clipping

}

timer++;//increment timer at rate of 38.5kHz

}

void loop(){

if (clipping){//if currently clipping

PORTB &= B11011111;//turn off clippng indicator led

clipping = 0;

}

frequency = 38462/period;//timer rate/period

//print results

Serial.print(frequency);

Serial.println(" hz");

if (frequency >= 105&& frequency <= 115) {

forward.on();

backward.off();

}

else

{

forward.off();

backward.off();

}

}

[RobertLM78]

I'd sure like to be able to watch the video - it's currently set to private.

[Videogamecollector123]

Sorry about that, should be fixed now. Guess the youtube app on my phone just uploads video's private as default.

Edited April 13, 2014 by Videogamecollector123

[RobertLM78]

Awesome! Reminds me of Vorticon's robot project .

[+Vorticon]

Very cool! Never thought of controlling an object with TI sounds This would make a great demo at the upcoming Chicago Faire in November.

Nice work.