1
\$\begingroup\$

I have a Terasic DE1, and have imported the maker's pinout file, which contains pin assignments for HEX digits. However, I noticed that each HEX digit has a dot next to it and I cannot find any pin assignments for those dots. I'm wondering if they are disabled or I can somehow map them myself. Can you help?

\$\endgroup\$
  • \$\begingroup\$ HEX is seldom used with decimals so the decimal points are often left unconnected as they are unused. They save on a driver transistor as you only have to multiplex the 7 segments. It might be possible to clone the segment drive circuit and connect it to the likely spare 8th bit in a port. Software libraries might need changing to get support. Perhaps you need to implement a decimal display routine from 0.001 to 9999. instead of 0000 to FFFF hex \$\endgroup\$ – KalleMP Oct 9 '16 at 20:09
2
\$\begingroup\$

From the "Using the 7-segment Displays" section of the user's manual for the DE1:

Note that the dot in each display is unconnected and cannot be used.

\$\endgroup\$
  • \$\begingroup\$ Well that's nice... I suppose you could tack a wire on to the relevant pin on the LED, and connect it to a spare I/O pin... \$\endgroup\$ – Brian Drummond Oct 9 '16 at 9:40

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.