TOP Contributors

  1. MIKROE (2784 codes)
  2. Alcides Ramos (404 codes)
  3. Shawon Shahryiar (307 codes)
  4. jm_palomino (132 codes)
  5. Bugz Bensce (97 codes)
  6. S P (73 codes)
  7. dany (71 codes)
  8. MikroBUS.NET Team (35 codes)
  9. NART SCHINACKOW (34 codes)
  10. Armstrong Subero (27 codes)

Most Downloaded

  1. Timer Calculator (141067 times)
  2. FAT32 Library (73612 times)
  3. Network Ethernet Library (58399 times)
  4. USB Device Library (48562 times)
  5. Network WiFi Library (44182 times)
  6. FT800 Library (43754 times)
  7. GSM click (30609 times)
  8. mikroSDK (29382 times)
  9. PID Library (27245 times)
  10. microSD click (27003 times)
Libstock prefers package manager

Package Manager

We strongly encourage users to use Package manager for sharing their code on Libstock website, because it boosts your efficiency and leaves the end user with no room for error. [more info]

< Back
Library

Keypad_I2c

Rating:

10

Author: dany

Last Updated: 2016-02-18

Package Version: 1.0.0.0

Category: Other Codes

Downloaded: 4296 times

Followed by: 1 user

License: MIT license  

Library for a 4x4 keypad connected to the PIC via an PCF8574 I2c expander (Two I2c lines in stead of 8 I/O pins). This saves a lot of PIC I/O pins.
Permits also small PIC's (with low pin count) to control a keypad.

No Abuse Reported

Do you want to subscribe in order to receive notifications regarding "Keypad_I2c" changes.

Do you want to unsubscribe in order to stop receiving notifications regarding "Keypad_I2c" changes.

Do you want to report abuse regarding "Keypad_I2c".

  • Information
  • Comments (3)

Library Blog

"Keypad_I2c" is a library to connect an 4x4 keypad via I2c to the PIC, using a PCF8574 expander. It uses the PCF8574 library.

In contradiction with the 4x4 keypad library from mE (connection via 8 I/O pins to the PIC), this version does not require pull down resistors (the internal ones of the PCF8574 are used in stead).

The functionality is the same as that of the mE (parallel connections) library, plus one addition: the function Keypad_I2c_PCF8574_Key_Status. It returns 16 bits (one word) with the status of all keys in the keypad: Key1 = bit 0; Key2 = bit 1;...; Key16 = bit 15. A bit with the value "1" is pressed, "0" is not pressed.

Have fun!

----------------------------------------------------------------------------------------------------------------------------------------------

2013-03-18: original version.

Connection diagram

Connection diagram

Connection Diagram for a 4x4 keypad. If there are less keypad columns or rows, then the free PCF8574 line(s) should be left unconnected.

View full image

-----------------------------------------------------------------------------------------------------------------------------------------------
2013-03-19: added the function Keypad_I2c_PCF8574_Key_Status.
It returns 16 bits (one word) with the status of all keys in the keypad:
Key1 = bit 0; Key2 = bit 1;...; Key16 = bit 15.
A bit with the value "1" is pressed, "0" is not pressed

-----------------------------------------------------------------------------------------------------------------------------------------------

2013-03-21: removed an omission in the example for the Keypad_I2c library: the call to "Soft_I2c_Init" was forgotten (still, it worked!).

---------------------------------------------------------------------------------------------------------------------------------------------
2013-03-25: Replaced the mikroBasic package files. The target compiler in them was still mikroPascal. Sorry for the inconvenience.

----------------------------------------------------------------------------------------------------------------------------------------

2014-03-13: The mikroBasic files and zip files have been updated. All mB sources are present now (not tested if compilable though).


2015-01-26: Replaced the mB files: all mB files are compilable now (which e.g. means that all "with" statements are dealt with). I could however not link and test the libraries (no mB licence).

ALSO FROM THIS AUTHOR

USB MSD Host Library

5

Library for making an USB host capable of reading and writing sectors from/to USB memory sticks (&quot;USB drives&quot; or &quot;pen drives&quot;).To read/write actual files from/to the USB memory stick you need still e.g. a Fat16 or Fat32 library (see example).

[Learn More]

TFTP HTTP pic based file server for FAT32 sd/mmc cards

5

This is a small TFTP fileserver, using an mmc/sd card for file storage. "Small" means the software does not have an error/retry/timeout mechanism. Also file download via HTTP is implemented (URL = 192.168.123.90). This project uses the Ethernet libraries v3.5 by Yo2Lio.

[Learn More]

PS2 Keyboard Read and write

5

Returns the native PS2 scan codes, no translation (except for some special scan codes, see the source file for the details). Capable of writing to the keyboard (e.g. giving commands to the keyboard).

[Learn More]