Question

I’m trying to start a connection from my Arduino Mega ADK to my Android but I keep getting the error below whenever I try to acc.powerOn()

Error: OSCOKIRQ failed to assert

This is the firmware that I’m trying to run:

#include <Wire.h>
#include <Servo.h>

#include <Max3421e.h>
#include <Usb.h>
#include <AndroidAccessory.h>

int led = 13;

int EnableMotors = 22;

int Motor1FW = 24;
int Motor1RW = 26;

int Motor2FW = 28;
int Motor2RW = 30;


AndroidAccessory acc("FRBB",
             "UgvBr",
             "DemoKit Arduino Board",
             "1.0",
             "http://www.android.com",
             "0000000012345678");



// the setup routine runs once when you press reset:
void setup() {

  // Setting Serial at 115200 bps
  Serial.begin(115200);

  // initialize the digital pin as an output.
  pinMode(led, OUTPUT);

  // Set up motor configs
  pinMode(EnableMotors, OUTPUT);
  pinMode(Motor1FW, OUTPUT);
  pinMode(Motor1RW, OUTPUT);
  pinMode(Motor2FW, OUTPUT);
  pinMode(Motor2RW, OUTPUT);

  // Powering the accessory
  acc.powerOn();             ///// <<<<<<<<<<< ERROR

}

// the loop routine runs over and over again forever:
void loop() {

  if(acc.isConnected()){

    digitalWrite(led, HIGH);   // turn the LED on (HIGH is the voltage level)
    digitalWrite(EnableMotors, HIGH);
    digitalWrite(Motor1FW, HIGH);
    digitalWrite(Motor2FW, HIGH);

    delay(2000);

    digitalWrite(led, LOW);   // turn the LED on (HIGH is the voltage level)
    digitalWrite(EnableMotors, LOW);
    digitalWrite(Motor1FW, LOW);
    digitalWrite(Motor2FW, LOW);

    delay(2000);
  }

}

I’ve been looking everywhere and I couldn’t find a solution to this problem yet. I also tried the DemoKit with Arduino.app on 1.0.1, but still the same issue. I’m developing it using Mac, but I don’t think that it is a problem.

For testing purposes, I uploaded a code to blink the LED, and it worked just fine.

Answer 1

Spent a good 8 hours having the exact same problem. Seems like the Max3421e.cpp is faulty. Try replacing:

boolean MAX3421E::reset()
{
  byte tmp = 0;
    regWr( rUSBCTL, bmCHIPRES );                        //Chip reset. This stops the oscillator
    regWr( rUSBCTL, 0x00 );                             //Remove the reset
    while(!(regRd( rUSBIRQ ) & bmOSCOKIRQ )) {          //wait until the PLL is stable
        tmp++;                                          //timeout after 256 attempts
        if( tmp == 0 ) {
            return( false );
        }
    }
    return( true );
}

with

boolean MAX3421E::reset()
{
    regWr( rUSBCTL, bmCHIPRES );                        //Chip reset. This stops the   oscillator
    regWr( rUSBCTL, 0x00 );                             //Remove the reset
    while(!(regRd(rUSBIRQ) & bmOSCOKIRQ)) ;
}

In Max3421e.cpp located in the USB_Host_Shield library (in your Arduino IDE library folder).
Basically the change does not allow an exit until the PLL is really stabilized.

Worked for me at least, good luck
(Original hints and more about the fix here: http://arduino.cc/forum/index.php?topic=68205.0)