PIC16F877 Nokia 3310 LCD Display IR Remote RC5 Control

The screen used in the remote control circuit is the nokia 3310 lcd microcontroller, the pic16f877 rc5 protocol can be used, and detailed frequency information about other control systems is given. In addition to the printed circuit eagle pcb and schematic files, source CCS C codes are also available 011_28.c, 16F877_mb.h, nokia_3310_mb.c, ir_read_mb.c, 24256_mb.c

PIC16F877 infrared remote control

NEC-SIRCS-JAPAN-RC5-SAMSUNG compatible, multi-protocol infrared remote control. Replaces up to 6 existing remotes with one remote. With manual learning function, LED display and/or LCD. 2V6-3V2, low power (sleep function) More protocols will be added later if needed (DENON, DAEWOO, MOTOROLA, RECS80.)

The main component is of course the PIC16LF877-04/L processor. The 8K program ROM contains all the inputs, outputs, timings, etc. works. There are six modes: SLEEP, IDLE, TRANSMISSION, RECEIVE, BACKUP & RESTORE.

There are two displays available: LED and/or LCD. So you can freely choose which one suits you best. Naturally, the Nokia LCD gives us much more detail, as we’ll see later.

Components: PIC16LF877-04/L (4Mhz PLCC Package), 24LC256 EEPROM (low power), 74HC148 encoder (SMD), optional Nokia 3310 graphic LCD (LPH-7779), IR LED, 5 optional LEDs, TSOP34836 IR receiver (low voltage ) )

Power consumption is only a few microamps in sleep mode!!

The circuit works with two AAA batteries (HR03). These can be rechargeable types. The voltage can drop to 2.5V. Battery life is several months (although NI-Mh batteries lose 1% of their power every day!)

Sleep mode is automatically activated after 20 seconds of inactivity (no buttons are pressed in standby mode.)

All user data is stored in the 24LC256 i²c EEPROM. It contains 32768 bytes (8 pages of 4096 bytes). That’s enough! Pages 0 to 5 (0x0xxx to 0x5xxx) each contain data from six devices (Aux, TV, Hifi, CD, DVD, Video) that we can use. Page 6 is not used, page 7 keeps all configuration data (for example which key is assigned to “PROGRAM” or “DVD” device…)

Up to 32 keys (4 columns by 8 rows) are supported. We have six fixed DEVICE SELECT keys (Aux, TV, Hifi, CD, DVD, Video), 1 fixed PROGRAM key, 1 fixed ENTER key. These eight hard keys need to be programmed on first boot (LCD shows “key init” “Program key?”, LEDs show “01000”) See more below. There is a maximum of 24 free COMMAND keys for each of the six devices. Not every free command switch contains protocols, this way we can mix protocols on every device page.

RB4..7 are the outputs of the four key columns. RB1..3 are the inputs from the 8-bit HC148 encoder.

While in sleep mode, pressing one of the keys on the key matrix wakes up the processor. HC148 to PIC interrupt INT/RB0, GS output goes low every time a key is pressed.

Also nice: the last device selected is stored in the EEPROM. Thus, the circuit will keep all settings and data safe even if power is not supplied. You can even make a full backup or restore of all data 😉

The IR receiver TSOP34836 (the output drops when an IR burst of about 36KHz is detected) only works in program mode. The receiver only gets 0.7 mA, but it’s still worth disabling it when not needed. More details on protocols and waveforms below.

There is of course an IR LED for IR transmission. Powered by a BC639. When enabled, it sends a burst of 37.1 kHz generated by the processor.

However, as you guessed, everything else is program code.

Source: www.techdesign.be PIC16F877 Nokia 3310 LCD Display IR Remote RC5 Control alternative link: