| ??? 05/12/06 16:10 Read: times |
#116105 - Interfacing a Bi-colour LED |
I'm sorry if this seems a really simple and obvious question, but I'm gonna destroy a rain forrest with my scribblings of schematics...
How can I use a standard port pin (not P0) of an Atmel family 8051 to drive a bi-colour led? i.e. low = one colour, high = another colour. The complication is I have a third state for the LED, off! The on/off signal comes from an opto isolator (CNY17-2, and when the issolated 12v source is on the LED's is on, in the colour determined by the 8051 port. I realise i need a combination of transistors and pull-ups, but I can't design a simple system to do the job. It's twisting my mellon.... Any help would be appreciated - Woody |
| Topic | Author | Date |
| Interfacing a Bi-colour LED | 01/01/70 00:00 | |
| a link to the bi-color LED datasheet | 01/01/70 00:00 | |
| Datasheet!! | 01/01/70 00:00 | |
| LED info | 01/01/70 00:00 | |
| He is right, the Vf max for the LEDs you | 01/01/70 00:00 | |
| More info on H bridge? | 01/01/70 00:00 | |
| that is what a H bridge usually is used | 01/01/70 00:00 | |
| be careful, but roll-yer-own | 01/01/70 00:00 | |
| Why no use a DPDT 5VDC relay? | 01/01/70 00:00 | |
| LED go poof | 01/01/70 00:00 | |
| Port pin go POOF! | 01/01/70 00:00 | |
| ?` | 01/01/70 00:00 | |
| Two inverters | 01/01/70 00:00 | |
| darn | 01/01/70 00:00 | |
| YES! | 01/01/70 00:00 | |
| Third color possible? | 01/01/70 00:00 | |
| Very nice however | 01/01/70 00:00 | |
| Two NAND's? | 01/01/70 00:00 | |
| how many LEDs | 01/01/70 00:00 | |
| a slight problem | 01/01/70 00:00 | |
| dynamic refresh | 01/01/70 00:00 | |
sure, but | 01/01/70 00:00 |