I²C between ATTiny85 (8MHz) and Arduino Uno

Question

I keep receiving the following error in myATTiny85-Slave code below:

sketch_mar12a.ino: In function 'void setup()':

sketch_mar12a:19: error: 'class USI_TWI_S' has no member named 'onRequest'

I have downloaded TinyWireS and TinyWireS.h clearly has a public function onRequest. I opened the .ZIP file (downloaded from https://github.com/rambo/TinyWire) and drag-dropped TinyWireS folder into the Arduino libraries folder. This is how I install ALL libraries.

I am using Arduino 1.0.6

What am I doing wrong?

ATTiny85-Slave Code:

#include "TinyWireS.h" // wrapper class for I2C slave routines
#define I2C_SLAVE_ADDR 0x26 // i2c slave address (38)
byte t=10;
void setup()
{ 
 TinyWireS.begin(I2C_SLAVE_ADDR); // init I2C Slave mode
 TinyWireS.onRequest(requestEvent);
}
void loop()
{
}
void requestEvent()
{ 
 TinyWireS.send(t);
}

Arduino Uno-Master Code:

 #include <Wire.h>
 #define I2C_SLAVE_ADDR 0x26 // i2c slave address (38)
 void setup() 
 {
 Wire.begin();
 Serial.begin(9600);
 }
 void loop() 
 {
 byte num;
 // read 1 byte, from address 0x26
 Wire.requestFrom(I2C_SLAVE_ADDR, 1);
 while(Wire.available()) {
 num = Wire.read();
 }
 
 Serial.print("num = ");
 Serial.println(num,DEC);
 }

• Gerben: How did you install the library?
• lucidgold: I opened the .ZIP file (downloaded from github.com/rambo/TinyWire) and drag-dropped TinyWireS folder into the Arduino libraries folder. This is how I install ALL libraries.
• diy_bloke: you may need to include: TinyWireS_stop_check(); in your loop

Answer 1

I was able to compile your code "ATTiny85-Slave Code" without problems.

You can try to extract the contents of the ZIP archive (i.e. the library) directly to the directory where your sketch is stored. #include "TinyWireS.h" should then pick up that version.

You should also switch on verbose output for the compilation to have a look at the directory in which the code is compiled. Here you would find (at least in my older Arduino IDE version) copies of the included files. (/tmp/build... on Linux systems.) You can then make sure the proper version of the files is used.

You can also search your drives for other copies of TinyWireS.h.

• lucidgold: Which version of Arduino IDE are you using? What board did you select?
• fuenfundachtzig: I am using Arduino IDE 1.0. It compiles with any board selection... Note that I did not install the Tiny hardware specs, but did a small hack in usiTwiSlace.c, declaring all missing symbols as ints.