7 Segment

The 7_segment board (depicted: the SPI version)

This is the documentation page for the 7_segment boards.

Assembly instructions

None: the board comes fully assembled.

Pinout

For the SPI connector see: SPI_connector_pinout. For the I2C connector see: I2C_connector_pinout.

LEDs

There are no LEDs, except for the display of course.

Jumper settings

See solder jumpers on how to change the solder jumper.

By changing the solder jumper SJ1, you can make the connector SPI1 (nearest the board edge) into an ICSP programming connector for the attiny48 on the board.

The software

Write ports

Some ports just set a single value. So writing more than one byte to such a port is redundant. Other ports are logically a stream of bytes. So writing more than one byte is encouraged.

The 7_segment board supports several read ports:

port	function
0x10	Write a bitmap to the display (see #bitmap) (4 bytes)
0x11	Write a hexadecimal number to the display (4 bytes)
0x12	write 0x01 to store the current display as startup display. Write 0x00 to return to the default.
0x20 .. 0x23	Write a bitmap to only 1 character
0x30 .. 0x33	Write a hexadecimal numer to only 1 character
0x40	Write a value other then 0x00 to light the bottom dot, 0x00 turns it off.
0x41	Write a value other then 0x00 to light the upper dot, 0x00 turns it off.
0x42	Write a value other then 0x00 to light both dots, 0x00 turns them off.
0xf0	change address.

Read ports

The 7_segment board supports several read ports:

port	function
0x01	identification string. (terminated with 0).
0x02	read eeprom (serial number).
0x10	Return the entire bitmap (see #bitmap) (4 bytes)
0x20 .. 0x23	Return the bitmap of 1 character

Bitmap

It is possible to tell the module to not show a hexadecimal digit, but to display a user-defined digit.
The most significant bit in this bitmap controls segment A, and the least significant bit controls one of the dots. The lower dot is controlled by digit 2, and the upper dot by digit 3.

Changelog

1.0

• Initial public release