Hello,

I'm running arduIMU v.D and I cannot get the code to compile if I use either analogRead/Write features. I get the following:

core.a(wiring_analog.c.o):(.data.analog_reference+0x0): multiple definition of `analog_reference'
arduimu.cpp.o:(.data.analog_reference+0x0): first defined here

Something about the way arduimu works seems to break the analog features.It looks like I need to do some direct port manipulation to read analog pin 0-4 (the pins I desire to read). Does someone have some advice on an equivalent piece of code to directly replace:

         analogRead(A0);

The reason for me doing this is that I am attempting to make a motion-based transmitter for multicopters, pitch and roll controlled by motion, but I would still need to poll some pots for yaw and throttle.

Thanks,

Ted 

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Hmm, I am guessing that there is a fundamental issue I am not grasping. Are the analog pins already being used to read the onboard sensors? 

This works for me.

//Potentiometer Connections:
//Wiper to A0
//One End to ground, the other to 5v
//LED blink rate controlled by Potentiometer
void setup()
{
Serial.begin(38400); //Set Serial out baud rate
pinMode(13, OUTPUT); //Yellow LED is output
}

void loop()
{
int value;
value = analogRead(A0); //Get Analog Value 0 - 1024
Serial.println(value); //Display on serial monitor

digitalWrite(13, HIGH); //Yellow LED On
delay(value); //Delay in milliseconds
digitalWrite(13, LOW); //Yellow LED Off
delay(value);
}

are you also running arduimu code along with that? I can do it standalone, but not while arduimu code is running. I would assume the normal SDA and SCL pins (A4 and A5) are used up, but for some reason any call to analogwrite/read results in the above. There most be something buried in the code that I do not understand. 

If you are using this software version and using hardware version V3:

// Version 1.9 Support for ArduIMU V3 Hardware with MPU6000 and HMC5883 magnetometer 

Then you must have this statement uncommented:

#define BOARD_VERSION 3     // 1 For  new V3

The ArduIMU has 3 versions.  V1 and V2 used all analog channels to get analog values from the separate accel and gyros.  V3 uses the MPU-6000 3 axis accel & gyro which has internal A/Ds that do it for you, thus you have all the analog ports free. I suspect your code is initializing the A/Ds along with their interrupts and then trying to do so again.  I would suggest going into the code and blow away all the code in the #defines for V1 and V2.

The link  below will show you what ports are being used in V3 and which are available for you use.  Currently I am using A0 - A3 with no problems.

https://code.google.com/p/arduimu-v3-ahrs-improvements/source/brows...

Got it, Thanks! I went through and commented out all references to boards < 3 AND I commented out this section.

/*
volatile uint8_t MuxSel=0;
volatile uint8_t analog_reference = DEFAULT;
volatile uint16_t analog_buffer[8];
volatile uint8_t analog_count[8];
*/

I am now able to use analogRead/Write in my code. So I decided to go back to stock code and then just comment out what I show above and NOT comment out any of the defines for < board 3 and it compiles, which I suppose is expected. 

I tried just wrapping that snippet of code up like this

#if BOARD_VERSION < 3
volatile uint8_t MuxSel=0;
volatile uint8_t analog_reference = DEFAULT;
volatile uint16_t analog_buffer[8];
volatile uint8_t analog_count[8];
#endif

but when I set the board type 1 or 2 I get issues about declaring variables on compile (even without analogRead/Write in there). I suppose that is because it still compiles the "void Read_adc_raw(void)" despite not needing to. 

So I have a very workable solution now considering I have board ver 3. Thank you very much Al Toma. You rock. 

You are welcome. You stated that you are making a motion-based transmitter for multicopters. Does that mean you are creating a hand held unit utilizing the IMU to output roll pitch which will be transmitted to your multicopter via an RF link like X-bee? Sounds do-able but I would think having several pots or even a 2-axis joystick on the same unit would be a little tricky to control - tilting the whole platform at the same time moving several pots on it seems a bit tricky. Good Luck!

By the way, they don't sell V1 and V2 IMUs any more so you don't really need the code in you project.

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