06_i2c_tcn75

Revision 0:84ce5e2a89b1, committed 2015-11-25

Comitter:

icserny

Date:

Wed Nov 25 07:00:30 2015 +0000

Commit message:

First version

Changed in this revision

diff -r 000000000000 -r 84ce5e2a89b1 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Nov 25 07:00:30 2015 +0000
@@ -0,0 +1,42 @@
+/** 06_i2c_tcn75
+ * Read temperature from a TCN75 (or LM75) I2C thermometer
+ * I2C address: 1 0 0 1 A2 A2 A0
+ *
+ * Hardware requirements:
+ *  - FRDM-KL25Z board
+ *  - TCN75 (or LM75) thermometer
+ *
+ * Wiring scheme:
+ *
+ * TCN75         FRDM-25KLZ
+ * -------------------------
+ * 1. SDA        D14 (PTE0 alias I2C_SDA)
+ * 2. SCL        D15 (PTE1 alias I2C_SCL)
+ * 3. ALERT       -- (not used)
+ * 4. GND        GND
+ * 5. A2         GND
+ * 6. A1         GND
+ * 7. A0         GND
+ * 8. VCC        3V3
+ */
+
+#include "mbed.h"
+I2C i2c(I2C_SDA, I2C_SCL);        // Arduino compatible pins
+const int addr = 0x90;            // TCN75 adress: 0x48<<1
+
+int main()
+{
+    char cmd[2];                  // data buffer
+    printf("\r\nTCN75 I2C thermometer\r\n");
+    cmd[0] = 0x01;                // Pointer to CONFIG register
+    cmd[1] = 0x00;                // Data for CONFOG register (Normal operation, comparator mode)
+    i2c.write(addr, cmd, 2);      // Send Address/comman and two bytes
+    while (1) {
+        wait(1);
+        cmd[0] = 0x00;            // Pointer to TEMP register
+        i2c.write(addr, cmd, 1);  // Write adress/command byte, then register address
+        i2c.read(addr, cmd, 2);   // Read 2 bytes from TEMP register
+        float temp = cmd[0]<<8|cmd[1];
+        printf("Temperatue = %.2f C\r\n", temp/256);
+    }
+}

diff -r 000000000000 -r 84ce5e2a89b1 mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Wed Nov 25 07:00:30 2015 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/9296ab0bfc11
\ No newline at end of file