Back in January of 2015, I wanted of use a PING)) ultrasonic sensor to measure distance and send it to the Atari using the 850 - RS232 ports.  I initially thought that  I could move my hand in front of the sensor and the resulting change in desistance could be used to change the frequency of the sound command.  This might have worked if the SIO port could be used to make sound .AND. transmit data to the 850 interface at the same time. It doesn't. So, I forgot about the sound and just got the distance data to the Atari and wrote up the blog entry.

 

 

Now that the Arduino Uno to PORTA shield (AU2PORTA) is at my disposal,  I can bypass the SIO port and receive the data through the Joystick ports to control the sound frequency. The Arduino reads the sensor data, scales it from 0 to 255, and sets the joystick pins. The Atari simply PEEKs the memory for PORTA and sets the SOUND command.

 

 

 

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Hardware setup -

 

 

1. Plug the AU2PORTA shield into the Arduino UNO.
2. Connect the PING)) sensor to the Shield.

         

          PING)) -------  Arduino

          GND                   GND

           5V                       5V

           SIG                      D2

3. Plug the AU2PORTA joystick cables into the correct Atari joystick port. 

 

 

 

Arduino UNO program -

 

/* This Arduino program receives data from a PING))sensor.

 Then scales the reading to an 8 bit number. That number is

 send to the Atari Joystick ports using the AU2PORTA shield.

 

Pitch data is also sent to the Arduino IDE serial monitor for troubleshooting.

 

PING))code example used to read sensor (Examples/06.Sensors/Ping)

 

 Kevin Packard   January 2019     

*/

 

// Atari PORTA(54016) mapped to pins on arduino

int porta0 = 4;

int porta1 = 5;

int porta2 = 6;

int porta3 = 7;

int porta4 = 8;

int porta5 = 9;

int porta6 = 10;

int porta7 = 11;

int trig1 = 3;

const int pingPin = 2; PING)) //sensor data pin

 

byte pitch = 0;

byte lastPitch = 0;

byte zero = 0;

 

void setPorta(byte byteToMap){

  // Sets digital pins to transfer data to Atari joystick ports(PORTA)

  // When digital port high, joystick pin shorted to ground or logic 0

  if (byteToMap & B00000001){digitalWrite(porta0,HIGH);}

    else {digitalWrite(porta0,LOW);}

  if (byteToMap & B00000010){digitalWrite(porta1,HIGH);}

    else {digitalWrite(porta1,LOW);}

  if (byteToMap & B00000100){digitalWrite(porta2,HIGH);}

    else {digitalWrite(porta2,LOW);}

  if (byteToMap & B00001000){digitalWrite(porta3,HIGH);}

    else {digitalWrite(porta3,LOW);}

  if (byteToMap & B00010000){digitalWrite(porta4,HIGH);}

    else {digitalWrite(porta4,LOW);}

  if (byteToMap & B00100000){digitalWrite(porta5,HIGH);}

    else {digitalWrite(porta5,LOW);}

  if (byteToMap & B01000000){digitalWrite(porta6,HIGH);}

    else {digitalWrite(porta6,LOW);}

  if (byteToMap & B10000000){digitalWrite(porta7,HIGH);}

    else {digitalWrite(porta7,LOW);}

}

 

void setup() {

  pinMode(porta0,OUTPUT);

  pinMode(porta1,OUTPUT);

  pinMode(porta2,OUTPUT);

  pinMode(porta3,OUTPUT);

  pinMode(porta4,OUTPUT);

  pinMode(porta5,OUTPUT);

  pinMode(porta6,OUTPUT);

  pinMode(porta7,OUTPUT);

  pinMode(trig1,OUTPUT);

  setPorta(zero);

  Serial.begin(9600);//

}

 

void loop() {

 

  long duration;                  // from Ping example

  pinMode(pingPin, OUTPUT);

  digitalWrite(pingPin, LOW);

  delayMicroseconds(2);

  digitalWrite(pingPin, HIGH);

  delayMicroseconds(5);

  digitalWrite(pingPin, LOW);

  pinMode(pingPin, INPUT);

  duration = pulseIn(pingPin, HIGH);  //

 

  if(duration < 200 || duration >3500){duration = 200;} // duration 200 us note off

 

  pitch = map(duration,200,3500,0,255); // Scale duration for Atari pitch setting

  if(pitch != lastPitch){               // look for pitch change from last setting

    digitalWrite(trig1,HIGH);           // let atari know not to read pitch while port is being set

    setPorta(pitch);                    // set pins with pitch data

    digitalWrite(trig1,LOW);            // let atari know data ok to read

    lastPitch = pitch;                  // store latest pitch

    Serial.print(pitch);                // display pitch in Serial Monitor window(if connected)

    Serial.println();

    }

   delay(100);                          // delay for PING)) and atari to sync.

   }// End of Listing

 

 

Atari BASIC code example -

 

100 IF STRIG(0)=0 THEN 100

200 PITCH=PEEK(54016)

210 IF PITCH=255 THEN VOLUME=0

220 IF PITCH<>255 THEN VOLUME=10

300 IF PITCH=LASTPITCH THEN 100

400 SOUND 0,PITCH,10,VOLUME

500 LASTPITCH=PITCH

510 ? PITCH

600 GOTO 100

 

 

While the programs are running, you should be able to move your hand (or other sound reflective object) closer and further from the PING)) sensor to hear a change in pitch.