Nano VM

I wrote a I2C library for the Raspberry Pi. It's done via WiringPi library.

I wrote an example how to read out a MPU 6050 accellerometer + gyro. So this would be a good start to learn how to use my I2C library.

The new source code is available on my Nano VM GitHub repo.

Here is the short example program:

//	i2clib.nanoc
//
//	reads i2c port with shared library
//	Stefan Pietzonke 2017

func main ()
	lint null = 0; lint one = 1;
	qint _fd = 0;
	
	lint _dll;
	
	lint _setup;
	lint _writereg8;
	lint _readreg8;
	
	string dllname[256] = "libi2c.so";
	string i2csetup[256] = "i2c_setup";
	string i2cwritereg8[256] = "i2c_writereg8";
	string i2creadreg8[256] = "i2c_readreg8";
	
	int gyroskop_xout;
	int gyroskop_yout;
	int gyroskop_zout;
	
	int accel_xout;
	int accel_yout;
	int accel_zout;
	
	#NESTED_CODE_ON;
	
//	open libi2c.so library in nanovm/lib directory
	lopen (_dll, dllname);	

//	set function handles
	lfunc (_dll, _setup, i2csetup);
	lfunc (_dll, _writereg8, i2cwritereg8);
	lfunc (_dll, _readreg8, i2creadreg8);
	
//	init module MPU 6050
	#ATOMIC;
	pushtostack (&68);
	
	lcall (_dll, _setup);
	get (_fd, >);
	#ATOMIC_END;
	
//	print "_fd: ", _fd; printn one;
	
//	setup MPU 6050
	#ATOMIC;
	pushtostack> (_fd, &6B, 0);
	
	lcall (_dll, _writereg8);
	#ATOMIC_END;
	
	@read_word_2c (_fd, &43);
	get (gyroskop_xout);
	
	@read_word_2c (_fd, &45);
	get (gyroskop_yout);

	@read_word_2c (_fd, &47);
	get (gyroskop_zout);
	

	@read_word_2c (_fd, &3B);
	get (accel_xout);
	
	@read_word_2c (_fd, &3D);
	get (accel_yout);

	@read_word_2c (_fd, &3F);
	get (accel_zout);
	
	
	print "gyroskop"; printn one;
	print "x: ", gyroskop_xout; printn one;
	print "y: ", gyroskop_yout; printn one;
	print "z: ", gyroskop_zout; printn one;
	printn one;
	
	print "accelleration"; printn one;
	print "x: ", accel_xout; printn one;
	print "y: ", accel_yout; printn one;
	print "z: ", accel_zout; printn one;
	printn one;
	printn one;
	
	exit null;
funcend

func read_word_i2c (qint fd, int reg)
	int h;
	int l;
	int value;
	
	#NESTED_CODE_ON;
	
//	print "fd: ", fd; printn 1;
	
	#ATOMIC;
	pushtostack (reg, fd);
	
	lcall (_dll, _readreg8);
	get (h, >);
	#ATOMIC_END;
	
	reg = ++;
	#ATOMIC;
	pushtostack (reg, fd);
	
	lcall (_dll, _readreg8);
	get (l, >);
	#ATOMIC_END;
	
	value = h << 8 + l;
	return (value);
funcend

func read_word_2c (qint fd, int reg)
	int val;
	int f;
	int ret;
	
	@read_word_i2c (fd, reg);
	get (val);
	
	f = val >= &8000;
	if f;
		ret = 65535 - val + 1;
		ret = 0 - ret;
	else;
		ret = val;
	endif;
	
	return (ret);
funcend
	
lab pushtostack;
#ASSEMB
	rts;
#ASSEMB_END

I released a portable version of my Nano VM on GitHub. Nano can now be copied on a USB stick and run from there. There is no installation required.

The binaries for Linux and Windows are in the bin directory. On Linux there are shell scripts which run the VM. This was needed because there is no Linux "execute" permission on a FAT32 file system. There is a README file in the archive.

Nano VM portable version

The archive is at the bottom. The README file in the archive is in English. There are binaries for Android also in the archive.