Sam Grove / MPR121

A device driver for the Freescale MPR121 capactive touch IC. Not optimized for any particular system, just a starting point to get the chip up in running in no time. Changes to registers init() method will tailor the library for end system use.

Dependents:   Seeed_Grove_I2C_Touch_Example MPR121_HelloWorld mbed_petbottle_holder_shikake test_DEV-10508 ... more

Datasheet:

http://cache.freescale.com/files/sensors/doc/data_sheet/MPR121.pdf

Information

Must add pull-ups to the I2C bus!!

Diff: MPR121.cpp

Revision:
1:cee45334b36a
Parent:
0:42add775212a
Child:
2:4c0d4b90a3ed
--- a/MPR121.cpp	Thu Mar 07 19:25:08 2013 +0000
+++ b/MPR121.cpp	Thu Mar 07 23:57:27 2013 +0000
@@ -109,6 +109,10 @@
 {
     _button = 0;
     _button_has_changed = 0;
+    // enable the 12 electrodes - allow disable to put device into
+    //  lower current consumption mode
+    MPR121::writeRegister(ECR, 0x8f);
+    // and attach the interrupt handler
     _irq->fall(this, &MPR121::handler);
     
     return;
@@ -116,9 +120,14 @@
 
 void MPR121::disable(void)
 {
+    // detach the interrupt handler
     _irq->fall(NULL);
     _button = 0;
     _button_has_changed = 0;
+    //  put the device in low current consumption mode - dont re-init registers
+    MPR121::writeRegister(ECR, 0x0);
+    MPR121::writeRegister(AUTO_CFG0, 0x0); // REG 0x7B
+    MPR121::writeRegister(AUTO_CFG1, 0x0); // REG 0x7C
     
     return;
 }
@@ -134,7 +143,7 @@
     return _button;
 }
 
-void MPR121::registerDump(void)
+void MPR121::registerDump(void) const
 {
     uint8_t reg_val = 0;
     
@@ -168,7 +177,7 @@
     return;
 }
 
-void MPR121::writeRegister(uint8_t reg, uint8_t data)
+void MPR121::writeRegister(uint8_t const reg, uint8_t const data) const
 {
     char buf[2] = {reg, data};
     uint8_t result = 0;
@@ -185,7 +194,7 @@
     return;
 }
 
-uint8_t MPR121::readRegister(uint8_t reg)
+uint8_t MPR121::readRegister(uint8_t const reg) const
 {
     uint8_t result = 1, data = 0;