This is an exercise in using Siemens # DLG 2416 2-character green LED displays with storage, selection, dimming, and decoding. Shift registers are used to interface to reduce pin count.
The design also a photocell for auto-dimming and a IR module for control with a TV remote. A Sony RM-V202 universal replacement remote control is used, set for Sony TV. Additional significant items are a LM34 to sense temperature and a real-time clock module using a Dallas DS-1307 IC, crystal and battery. It has eight display modes, which are shown in the photos. There are two for time and temperature, two to adjust time, two messages stored in EEPROM and two messages stored in the DS-1307. These latter can be changed using the external keyboard described elsewhere.
There are two Picaxe processors. A 14M handles the IR control and the keyboard. An 18X does the rest. Data is transferred between them by serial with a handshake. A switch selects keyboard or infrared mode.
The temperature sensor has an amplifier adjusted for accurate readout. It is located outside the box and thermally insulated.
The real-time clock was originally set with an ad-hoc program. Since its battery is supposed to be good for seven years, adjustment was provided only to increment or decrement by minutes to correct for drift, and by hours for daylight-saving time.
For more information go to my web site:
http://projects.worsleyassociates.com/LED_Display/
The design also a photocell for auto-dimming and a IR module for control with a TV remote. A Sony RM-V202 universal replacement remote control is used, set for Sony TV. Additional significant items are a LM34 to sense temperature and a real-time clock module using a Dallas DS-1307 IC, crystal and battery. It has eight display modes, which are shown in the photos. There are two for time and temperature, two to adjust time, two messages stored in EEPROM and two messages stored in the DS-1307. These latter can be changed using the external keyboard described elsewhere.
There are two Picaxe processors. A 14M handles the IR control and the keyboard. An 18X does the rest. Data is transferred between them by serial with a handshake. A switch selects keyboard or infrared mode.
The temperature sensor has an amplifier adjusted for accurate readout. It is located outside the box and thermally insulated.
The real-time clock was originally set with an ad-hoc program. Since its battery is supposed to be good for seven years, adjustment was provided only to increment or decrement by minutes to correct for drift, and by hours for daylight-saving time.
For more information go to my web site:
http://projects.worsleyassociates.com/LED_Display/