7 Segment

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spi_7segment
The 7_segment board (depicted: the SPI version)

This is the documentation page for the 7_segment boards.

Overview

Assembly instructions

None: the board comes fully assembled.

Possible Configurations

External resources

Datasheets

Additional software

Related projects

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.

Programming

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.

Default operation

Future hardware enhancements

Future software enhancements

Changelog

1.0

  • Initial public release