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Diffstat (limited to 'ext/I2CSlave.h')
| -rw-r--r-- | ext/I2CSlave.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/ext/I2CSlave.h b/ext/I2CSlave.h new file mode 100644 index 0000000..ddf9d5f --- /dev/null +++ b/ext/I2CSlave.h @@ -0,0 +1,154 @@ +/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef MBED_I2C_SLAVE_H
+#define MBED_I2C_SLAVE_H
+
+#include "platform.h"
+
+#if DEVICE_I2CSLAVE
+
+#include "i2c_api.h"
+
+namespace mbed {
+
+/** An I2C Slave, used for communicating with an I2C Master device
+ *
+ * Example:
+ * @code
+ * // Simple I2C responder
+ * #include <mbed.h>
+ *
+ * I2CSlave slave(p9, p10);
+ *
+ * int main() {
+ * char buf[10];
+ * char msg[] = "Slave!";
+ *
+ * slave.address(0xA0);
+ * while (1) {
+ * int i = slave.receive();
+ * switch (i) {
+ * case I2CSlave::ReadAddressed:
+ * slave.write(msg, strlen(msg) + 1); // Includes null char
+ * break;
+ * case I2CSlave::WriteGeneral:
+ * slave.read(buf, 10);
+ * printf("Read G: %s\n", buf);
+ * break;
+ * case I2CSlave::WriteAddressed:
+ * slave.read(buf, 10);
+ * printf("Read A: %s\n", buf);
+ * break;
+ * }
+ * for(int i = 0; i < 10; i++) buf[i] = 0; // Clear buffer
+ * }
+ * }
+ * @endcode
+ */
+class I2CSlave {
+
+public:
+ enum RxStatus {
+ NoData = 0,
+ ReadAddressed = 1,
+ WriteGeneral = 2,
+ WriteAddressed = 3
+ };
+
+ /** Create an I2C Slave interface, connected to the specified pins.
+ *
+ * @param sda I2C data line pin
+ * @param scl I2C clock line pin
+ */
+ I2CSlave(PinName sda, PinName scl);
+
+ /** Set the frequency of the I2C interface
+ *
+ * @param hz The bus frequency in hertz
+ */
+ void frequency(int hz);
+
+ /** Checks to see if this I2C Slave has been addressed.
+ *
+ * @returns
+ * A status indicating if the device has been addressed, and how
+ * - NoData - the slave has not been addressed
+ * - ReadAddressed - the master has requested a read from this slave
+ * - WriteAddressed - the master is writing to this slave
+ * - WriteGeneral - the master is writing to all slave
+ */
+ int receive(void);
+
+ /** Read from an I2C master.
+ *
+ * @param data pointer to the byte array to read data in to
+ * @param length maximum number of bytes to read
+ *
+ * @returns
+ * 0 on success,
+ * non-0 otherwise
+ */
+ int read(char *data, int length);
+
+ /** Read a single byte from an I2C master.
+ *
+ * @returns
+ * the byte read
+ */
+ int read(void);
+
+ /** Write to an I2C master.
+ *
+ * @param data pointer to the byte array to be transmitted
+ * @param length the number of bytes to transmite
+ *
+ * @returns
+ * 0 on success,
+ * non-0 otherwise
+ */
+ int write(const char *data, int length);
+
+ /** Write a single byte to an I2C master.
+ *
+ * @data the byte to write
+ *
+ * @returns
+ * '1' if an ACK was received,
+ * '0' otherwise
+ */
+ int write(int data);
+
+ /** Sets the I2C slave address.
+ *
+ * @param address The address to set for the slave (ignoring the least
+ * signifcant bit). If set to 0, the slave will only respond to the
+ * general call address.
+ */
+ void address(int address);
+
+ /** Reset the I2C slave back into the known ready receiving state.
+ */
+ void stop(void);
+
+protected:
+ i2c_t _i2c;
+};
+
+} // namespace mbed
+
+#endif
+
+#endif
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