MPR121 sometimes needs a little time to reply to I2C requests, so kee…

…p askin'
adafruit · Dec 27, 2014 · 6f33121 · 6f33121
1 parent f998062
commit 6f33121
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Showing 2 changed files with 4 additions and 3 deletions.
diff --git a/Adafruit_MPR121.cpp b/Adafruit_MPR121.cpp
@@ -90,7 +90,6 @@ uint16_t  Adafruit_MPR121::baselineData(uint8_t t) {
 
 uint16_t  Adafruit_MPR121::touched(void) {
   uint16_t t = readRegister16(MPR121_TOUCHSTATUS_L);
-
   return t & 0x0FFF;
 }
 
@@ -101,15 +100,15 @@ uint8_t Adafruit_MPR121::readRegister8(uint8_t reg) {
     Wire.beginTransmission(_i2caddr);
     Wire.write(reg);
     Wire.endTransmission(false);
-    Wire.requestFrom(_i2caddr, 1);
+    while (Wire.requestFrom(_i2caddr, 1) != 1);
     return ( Wire.read());
 }
 
 uint16_t Adafruit_MPR121::readRegister16(uint8_t reg) {
     Wire.beginTransmission(_i2caddr);
     Wire.write(reg);
     Wire.endTransmission(false);
-    Wire.requestFrom(_i2caddr, 2);
+    while (Wire.requestFrom(_i2caddr, 2) != 2);
     uint16_t v = Wire.read();
     v |=  ((uint16_t) Wire.read()) << 8;
     return v;

diff --git a/examples/MPR121test/MPR121test.ino b/examples/MPR121test/MPR121test.ino
@@ -27,6 +27,8 @@ uint16_t lasttouched = 0;
 uint16_t currtouched = 0;
 
 void setup() {
+  while (!Serial);        // needed to keep leonardo/micro from starting too fast!
+
   Serial.begin(9600);
   Serial.println("Adafruit MPR121 Capacitive Touch sensor test");