Original
Fork of PCA9547 by
PCA9547.cpp@7:995f209b8707, 2014-08-12 (annotated)
- Committer:
- okano
- Date:
- Tue Aug 12 22:40:35 2014 +0000
- Revision:
- 7:995f209b8707
- Parent:
- 4:3c0af4c37587
- Child:
- 8:c716fb3ccb8d
sample of different I2C frequency for each devices
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
okano | 3:7e884a7805b1 | 1 | /** |
okano | 3:7e884a7805b1 | 2 | * PCA9547 library |
okano | 1:47f2cf4c6619 | 3 | * |
okano | 3:7e884a7805b1 | 4 | * @author Tedd OKANO |
okano | 3:7e884a7805b1 | 5 | * @version 0.1 |
okano | 3:7e884a7805b1 | 6 | * @date July-2014 |
okano | 3:7e884a7805b1 | 7 | * |
okano | 3:7e884a7805b1 | 8 | * PCA9547: an I2C bus multiplexer control library |
okano | 1:47f2cf4c6619 | 9 | * |
okano | 3:7e884a7805b1 | 10 | * PCA9547 is an I2C multiplexer which enables to select 1:8 multiplexed I2C bus. |
okano | 3:7e884a7805b1 | 11 | * The multiplexer is useful for deviding I2C bus to avoiding slave address conflict and separating capacitive loads. |
okano | 1:47f2cf4c6619 | 12 | * |
okano | 4:3c0af4c37587 | 13 | * For more information about PCA9547: |
okano | 3:7e884a7805b1 | 14 | * http://www.nxp.com/documents/data_sheet/PCA9547.pdf |
okano | 3:7e884a7805b1 | 15 | * |
okano | 1:47f2cf4c6619 | 16 | */ |
okano | 3:7e884a7805b1 | 17 | |
okano | 0:662ab6a5aa97 | 18 | #include "PCA9547.h" |
okano | 0:662ab6a5aa97 | 19 | |
okano | 0:662ab6a5aa97 | 20 | PCA9547::PCA9547( PinName sda, PinName scl, char i2c_address ) : i2c( sda, scl ), _i2c_addr( i2c_address ) |
okano | 0:662ab6a5aa97 | 21 | { |
okano | 0:662ab6a5aa97 | 22 | // do nothing. |
okano | 0:662ab6a5aa97 | 23 | // leave it in default state. |
okano | 7:995f209b8707 | 24 | |
okano | 7:995f209b8707 | 25 | // FOR TEST PURPOSE |
okano | 7:995f209b8707 | 26 | // THIS DEVICE USES DIFFERENT I2C FREQUENCY |
okano | 7:995f209b8707 | 27 | i2c.frequency( 400 * 1000 ); |
okano | 0:662ab6a5aa97 | 28 | } |
okano | 0:662ab6a5aa97 | 29 | |
okano | 0:662ab6a5aa97 | 30 | PCA9547::~PCA9547() |
okano | 0:662ab6a5aa97 | 31 | { |
okano | 0:662ab6a5aa97 | 32 | |
okano | 0:662ab6a5aa97 | 33 | } |
okano | 0:662ab6a5aa97 | 34 | |
okano | 0:662ab6a5aa97 | 35 | void PCA9547::select( char channel ) |
okano | 0:662ab6a5aa97 | 36 | { |
okano | 0:662ab6a5aa97 | 37 | char data = 0x08 | channel; |
okano | 0:662ab6a5aa97 | 38 | |
okano | 2:c3459a955c8c | 39 | i2c.write( _i2c_addr, &data, 1 ); |
okano | 0:662ab6a5aa97 | 40 | } |
okano | 2:c3459a955c8c | 41 | |
okano | 2:c3459a955c8c | 42 | void PCA9547::disable( void ) |
okano | 2:c3459a955c8c | 43 | { |
okano | 2:c3459a955c8c | 44 | char data = 0x00; |
okano | 2:c3459a955c8c | 45 | |
okano | 2:c3459a955c8c | 46 | i2c.write( _i2c_addr, &data, 1 ); |
okano | 2:c3459a955c8c | 47 | } |