My next challenge is to save signed integers to an I2c memory chip. They will only range from say -300 to +900 so will be saving as two bytes (high and low) as if a 16bit integer, not the incoming MMBasic 64bit.

For example -

Dim as integer Xmin,Dhi,Dlo
Xmin=-298
...
...
I2c write &h50,0,4,1,0,Dhi,Dlo

I'm already writing small positive MMBasic 64bit integers as single bytes as MMBasic converts/truncates to 8bit in the i2c command itself.

Wondering what the fastest and most efficient way would be to do this ?

bin2str$ was designed for specifically this
Edited 2026-04-15 03:23 by matherp

  matherp said  

bin2str$ was designed for specifically this

I'll have a play sir....

A kind of "hack"  according to C, which relies on the Pico using an ARM with a little-endian format:

  matherp said  

bin2str$ was designed for specifically this

First attempt results in "Error : Argument Count"

a$=Bin2Str$(INT16,xmin,BIG)
I2C2 write &h50,0,4,1,0,a$

Hence writing 4 bytes... '1','0','2byte string' ??

  bfwolf said  

A kind of "hack"  according to C, which relies on the Pico using an ARM with a little-endian format:

Dim XminAddr As integer
XminAddr = PEEK(VARADDR Xmin)
Dlo = PEEK(BYTE XminAddr)
Dhi = PEEK(BYTE (XminAddr+1))

Interesting 😎

  Quote  

First attempt results in "Error : Argument Count"

a$=Bin2Str$(INT16,xmin,BIG)
I2C2 write &h50,0,4,1,0,a$

When writing a string to a 24Cxx EEPROM the 2 address bytes need to be added to the start of the data.
So perhaps try:-


Currently you are trying to write a mix of integer bytes and a string which I2C WRITE doesn't accept.
Edited 2026-04-15 11:04 by phil99