nRF52 I2CSlave Implementation

drivers/I2CSlave.h

@@ -34,39 +34,95 @@ namespace mbed {
  *
  * @note Synchronization level: Not protected
  *
- * Example Simple I2C responder:
+ * Example Simple I2C slave and master (requires two Mbed-boards):
  * @code
  * #include <mbed.h>
+ * #include <mbed_wait_api.h>
+ * #include <string.h>
  *
- * const int SLAVE_ADDRESS = 0xA0;
- * const char message[] = "Slave!";
+ * #define BUILD_I2C_SLAVE 1 // Build for slave or master of this example
+ *
+ * #define SLAVE_ADDR 0xA0
+ * #define BUFFER_SIZE 6
+ *
+ * #if BUILD_I2C_SLAVE
+ *
+ * // Slave side of the example
+ *
+ * #if !DEVICE_I2CSLAVE
+ * #error [NOT_SUPPORTED] I2C Slave is not supported
+ * #endif
  *
  * I2CSlave slave(I2C_SDA, I2C_SCL);
  *
  * int main() {
- *     slave.address(SLAVE_ADDRESS);
+ *
+ *     char buf[BUFFER_SIZE] = "ABCDE";
+ *
+ *     slave.address(SLAVE_ADDR);
  *     while (1) {
- *         int operation = slave.receive();
- *         switch (operation) {
+ *         int i = slave.receive();
+ *         switch (i) {
  *             case I2CSlave::ReadAddressed:
- *                 int status = slave.write(message, sizeof(message));
- *                 if (status == 0) {
- *                     printf("Written message: %s\n", message);
- *                 } else {
- *                     printf("Failed to write message.\n");
- *                 }
+ *                 // Write back the buffer from the master
+ *                 slave.write(buf, BUFFER_SIZE);
+ *                 printf("Written to master (addressed): %s\n", buf);
  *                 break;
+ *
  *             case I2CSlave::WriteGeneral:
- *                 int byte_read = slave.read();
- *                 printf("Read General: %c (%d)\n", byte_read, byte_read);
+ *                 slave.read(buf, BUFFER_SIZE);
+ *                 printf("Read from master (general): %s\n", buf);
  *                 break;
+ *
  *             case I2CSlave::WriteAddressed:
- *                 int byte_read = slave.read();
- *                 printf("Read Addressed: %c (%d)\n", byte_read, byte_read);
+ *                 slave.read(buf, BUFFER_SIZE);
+ *                 printf("Read from master (addressed): %s\n", buf);
  *                 break;
  *         }
  *     }
  * }
+ *
+ * #else
+ *
+ * // Master side of the example
+ *
+ * I2C master(I2C_SDA, I2C_SCL);
+ *
+ * static const char* to_send[] = { "abcde", "12345", "EFGHI" };
+ *
+ * int main() {
+ *     char buf[BUFFER_SIZE];
+ *     int send_index = 0;
+ *
+ *     while (1) {
+ *         strcpy(buf, to_send[send_index]);
+ *
+ *         // Write the new message to the slave
+ *         if (master.write(SLAVE_ADDR, buf, BUFFER_SIZE)) {
+ *             printf("Failed to write to slave!\n");
+ *         } else {
+ *             printf("Written to slave: %s\n", buf);
+ *         }
+ *
+ *         // Read what the slave has (should be identical)
+ *         if (master.read(SLAVE_ADDR, buf, BUFFER_SIZE)) {
+ *             printf("Failed to read from slave!\n");
+ *         } else {
+ *             printf("Read from slave: %s\n", buf);
+ *         }
+ *
+ *         // Change the message we're writing to the slave
+ *         send_index++;
+ *         if (send_index > 2) {
+ *             send_index = 0;
+ *         }
+ *
+ *         wait_us(500000); // Wait 0.5s
+ *     }
+ * }
+ *
+ * #endif
+ *
  * @endcode
  */
 class I2CSlave {

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/TARGET_MCU_NRF52832/config/sdk_config.h

@@ -3908,20 +3908,20 @@
 // <e> NRFX_TWIS_ENABLED - nrfx_twis - TWIS peripheral driver
 //==========================================================
 #ifndef NRFX_TWIS_ENABLED
-#define NRFX_TWIS_ENABLED 0
+#define NRFX_TWIS_ENABLED 1
 #endif
 // <q> NRFX_TWIS0_ENABLED  - Enable TWIS0 instance
 
 
 #ifndef NRFX_TWIS0_ENABLED
-#define NRFX_TWIS0_ENABLED 0
+#define NRFX_TWIS0_ENABLED 1
 #endif
 
 // <q> NRFX_TWIS1_ENABLED  - Enable TWIS1 instance
 
 
 #ifndef NRFX_TWIS1_ENABLED
-#define NRFX_TWIS1_ENABLED 0
+#define NRFX_TWIS1_ENABLED 1
 #endif
 
 // <q> NRFX_TWIS_ASSUME_INIT_AFTER_RESET_ONLY  - Assume that any instance would be initialized only once

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/TARGET_MCU_NRF52840/config/sdk_config.h

@@ -3908,20 +3908,20 @@
 // <e> NRFX_TWIS_ENABLED - nrfx_twis - TWIS peripheral driver
 //==========================================================
 #ifndef NRFX_TWIS_ENABLED
-#define NRFX_TWIS_ENABLED 0
+#define NRFX_TWIS_ENABLED 1
 #endif
 // <q> NRFX_TWIS0_ENABLED  - Enable TWIS0 instance
 
 
 #ifndef NRFX_TWIS0_ENABLED
-#define NRFX_TWIS0_ENABLED 0
+#define NRFX_TWIS0_ENABLED 1
 #endif
 
 // <q> NRFX_TWIS1_ENABLED  - Enable TWIS1 instance
 
 
 #ifndef NRFX_TWIS1_ENABLED
-#define NRFX_TWIS1_ENABLED 0
+#define NRFX_TWIS1_ENABLED 1
 #endif
 
 // <q> NRFX_TWIS_ASSUME_INIT_AFTER_RESET_ONLY  - Assume that any instance would be initialized only once