Connect a MCU6050 the the scamp

[Jan Kromhout]

Using the code below, I'm trying to connect an MCU6050 to the Scamp3.
At first, the code seems to work. The I2C clock speed is reduced.
But after reading the sensor a few times, the program hangs, or the I2C is broken.
With the test program, I call the MCU, delete the result, and print a dot.
But after calling the program about 15 times, the program stops.

I've also written test code for the Arduino Uno, and it runs perfectly, without
the system hanging.

Include also the basic procedure arduino to read the MCU6050.

My question is, am I doing something wrong?

--MCU6050
marker --MCU6050

$68 constant MCU6050 

150 $2de ! \ Verlaag de kloksnelheid I2C


: read8 ( reg -- value )
    start                   \ start I2C transmissie
    MCU6050 write drop      \ stuur schrijf commando 
    send drop               \ stuur register adres 
    repstart                \ herstart voor lees operatie
    MCU6050 read drop       \ stuur lees commando 
    receive                 \ ontvang byte van slave
    nack                    \ stuur NACK (laatste byte)
    stop                    \ stop I2C transmissie
;

: read16 ( reg -- value )
    start                   \ start I2C transmissie
    MCU6050 write drop      \ schrijf 
    send drop               \ schrijf reg
    repstart
    MCU6050 read drop       \ lees
    receive ack             \ eerste byte (hoge byte)
    receive nack            \ tweede byte (lage byte)
    stop
    swap                    \ get hige byte
    8 lshift +              \ (hoge_byte << 8) + lage_byte
;

: write8 ( reg value -- )
    start                   \ start I2C transmissie
    MCU6050 write drop      \ schrijf naar MPU adres (leaves ACK)
    swap                    \ breng reg naar top ( value reg )
    send drop               \ stuur register adres
    send drop               \ verstuur hoge byte van value
    stop
;

: init6050 ( -- )
    150 $2de !      \ change clk speed I2C
    $6b 0 write8    \ schrijf 0 naar power management register
    $19 7 write8    \ sample rate = 1kHz/(1+7) = 125Hz 
    $1b 0 write8    \ ±2g range 
    $0b 0 write8    \ ±250°/s range
;

: readAll ( reg -- val0 val1 val2 )
    start                   \ start I2C transmissie
    MCU6050 write drop      \ schrijf naar MPU adres (leaves ACK)
    send drop               \ schrijf reg
    repstart
    MCU6050 read drop
    receive ack             \ eerste byte (hoge byte)
    receive ack             \ tweede byte (lage byte)
    swap                    \ get high byte
    8 lshift +              \ (high_byte << 8) + low-byte
    receive ack             \ eerste byte (hoge byte)
    receive ack             \ tweede byte (lage byte)
    swap                    \ get high byte
    8 lshift +              \ (high_byte << 8) + low-byte
    receive ack             \ eerste byte (hoge byte)
    receive nack            \ tweede byte (lage byte)
    swap                    \ get high byte
    8 lshift +              \ (high_byte << 8) + low-byte
    stop
;

: .6050
    cr
    $3b readAll  5 u.r 5 u.r 5 u.r  cr 
    $43 readAll  5 u.r 5 u.r 5 u.r  cr  
;


: CLS
    27 emit ." [2J" \ Clear entire screen
;

: HOME ( -- )  
    27 emit ." [H"  \ Move cursor to home (1,1)
;

: CLR ( -- )
    CLS HOME        \ Clear screen and go home
;


: test6050
    init6050
    200 ms
    begin
        \ CLR
        $3b readAll drop drop drop ." . "
        500 ms
    key? until
;

Arduino:

void getRawData(){
  Wire.beginTransmission(MPU);
  Wire.write(0x3b); // Start with register 0x3B (ACCEL_XOUT_H)
  Wire.endTransmission(true);
  Wire.requestFrom(MPU, 6, true);
  AccX = (Wire.read() << 8 | Wire.read()); // X-axis value
  AccY = (Wire.read() << 8 | Wire.read()); // Y-axis value
  AccZ = (Wire.read() << 8 | Wire.read()); // Z-axis value
  Wire.endTransmission(true);

  Wire.beginTransmission(MPU);
  Wire.write(0x43);
  Wire.endTransmission(true);
  Wire.requestFrom(MPU, 6, true);
  GyroX = Wire.read() << 8 | Wire.read();
  GyroY = Wire.read() << 8 | Wire.read();
  GyroZ = Wire.read() << 8 | Wire.read();
  Wire.endTransmission(true);
}

[Mikael Nordman]

Is your data stack balanced? Does it grow or shrink?

[Jan Kromhout]

I have checked every word en the stack behavior is as it should. In my test program the stack is in balance!

[Jan Kromhout]

I have checked every word en the stack behavior is as it should. In my test program the stack is in balance!