font and bitmap ?les combined up to 16 Kbytes. This section co
vers uploading, downloading, deleting and
moving ?les, as well as getting the remaining space or wiping
the ?lesystem.
12.1.1 File Upload Protocol
In order to allow fonts and bitmaps to be uploaded to the on board ?ash memory Matrix Orbital has
developed a simple protocol that supports RS-232/TTL or I2C communications. In order to begin a ?le
transmission the ?rst step will be to provide the display mod
ule with the appropriate command bytes, mean-
ing the command pre?x, 0xFE, followed by the command number,
0x24 for a font ?le, or 0x5E for a bitmap
?le. This will begin the ?le transfer sequence. The next step
will be to request a reference identi?cation
number (ref ID) which will allow you to identify the ?le for fu
ture use. Reference ID numbers can be any
byte between 0x01 and 0xFF, however each ID must be unique.
The next part of uploading a font ?le is to provide the display
module with the two byte ?le size of the
data that you wish to transfer, LSB to MSB. The LSB must be transmitted ?rst followed by the MSB. After
receiving the MSB the display module will send a con?rm byte,
0x01, if the ?le ?ts and continue, or decline
byte, 0x08, and terminate the session.
Byte
Description
0x01
Con?rm: Will continue the ?le transfer.
0x08
Decline: Terminate the session.
The last part of uploading a font ?le is to upload the ?le data.
After transmitting each byte of the ?le the
module will echo the byte and wait for a con?rmation byte of 0x
01 until the ?le has completed uploading.
Below is an example of uploading the font ?le which we created
in
Section 5.1.2 on page 20.
Matrix Orbital GLK12232-25
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