I am attempting to drive a Matrix Orbital LCD0821 display using a 400kHz I2C bus.
I am using 10k Pull-up resistors on both SCL and SDA.
I have connected the display to an 18X and used the software i2c routines.
I have also connected the display to a 28X1 and used the hardware i2c routines.
In both cases, the display obeys every command I send it, with one critical flaw:
When write a character to the device after a command (all commands are 2 characters, prefixed with the value 254) I get an extra character in the display window - the custom bitmap stored in address $00 of the font table.
This happens with every printable character except $0D (which is a carriage return)
It also happens immediately after a clear-screen command - I get a $00 character in the top left corner before I display any characters.
Has anyone else encountered a similar problem with I2C connections to LCD displays? Has anyone had any luck getting this particular display to work with a PICAXE?
I have posted requests for help on MAtrix Orbital's forum as well, but any help would be appreciated.
I am using 10k Pull-up resistors on both SCL and SDA.
I have connected the display to an 18X and used the software i2c routines.
I have also connected the display to a 28X1 and used the hardware i2c routines.
In both cases, the display obeys every command I send it, with one critical flaw:
When write a character to the device after a command (all commands are 2 characters, prefixed with the value 254) I get an extra character in the display window - the custom bitmap stored in address $00 of the font table.
This happens with every printable character except $0D (which is a carriage return)
It also happens immediately after a clear-screen command - I get a $00 character in the top left corner before I display any characters.
Has anyone else encountered a similar problem with I2C connections to LCD displays? Has anyone had any luck getting this particular display to work with a PICAXE?
I have posted requests for help on MAtrix Orbital's forum as well, but any help would be appreciated.