Nathan Yonkee
/
Nucleo_i2c_master
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Revision 0:94dbc6f9a730, committed 2017-04-21
- Comitter:
- tulanthoar
- Date:
- Fri Apr 21 19:49:23 2017 +0000
- Child:
- 1:9cdd4df37645
- Commit message:
- copy of i2c master example
Changed in this revision
| main.cpp | Show annotated file Show diff for this revision Revisions of this file |
| mbed.bld | Show annotated file Show diff for this revision Revisions of this file |
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Fri Apr 21 19:49:23 2017 +0000
@@ -0,0 +1,71 @@
+#include "mbed.h"
+
+#define LM75_REG_TEMP (0x00) // Temperature Register
+#define LM75_REG_CONF (0x01) // Configuration Register
+#define LM75_ADDR (0x90) // LM75 address
+
+I2C i2c(I2C_SDA, I2C_SCL);
+
+DigitalOut myled(LED1);
+
+Serial pc(SERIAL_TX, SERIAL_RX);
+
+volatile char TempCelsiusDisplay[] = "+abc.d C";
+
+int main()
+{
+
+ char data_write[2];
+ char data_read[2];
+
+ /* Configure the Temperature sensor device STLM75:
+ - Thermostat mode Interrupt
+ - Fault tolerance: 0
+ */
+ data_write[0] = LM75_REG_CONF;
+ data_write[1] = 0x02;
+ int status = i2c.write(LM75_ADDR, data_write, 2, 0);
+ if (status != 0) { // Error
+ while (1) {
+ myled = !myled;
+ wait(0.2);
+ }
+ }
+
+ while (1) {
+ // Read temperature register
+ data_write[0] = LM75_REG_TEMP;
+ i2c.write(LM75_ADDR, data_write, 1, 1); // no stop
+ i2c.read(LM75_ADDR, data_read, 2, 0);
+
+ // Calculate temperature value in Celcius
+ int tempval = (int)((int)data_read[0] << 8) | data_read[1];
+ tempval >>= 7;
+ if (tempval <= 256) {
+ TempCelsiusDisplay[0] = '+';
+ } else {
+ TempCelsiusDisplay[0] = '-';
+ tempval = 512 - tempval;
+ }
+
+ // Decimal part (0.5°C precision)
+ if (tempval & 0x01) {
+ TempCelsiusDisplay[5] = 0x05 + 0x30;
+ } else {
+ TempCelsiusDisplay[5] = 0x00 + 0x30;
+ }
+
+ // Integer part
+ tempval >>= 1;
+ TempCelsiusDisplay[1] = (tempval / 100) + 0x30;
+ TempCelsiusDisplay[2] = ((tempval % 100) / 10) + 0x30;
+ TempCelsiusDisplay[3] = ((tempval % 100) % 10) + 0x30;
+
+ // Display result
+ pc.printf("temp = %s\n", TempCelsiusDisplay);
+ myled = !myled;
+ wait(1.0);
+ }
+
+}
+
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Fri Apr 21 19:49:23 2017 +0000 @@ -0,0 +1,1 @@ +https://mbed.org/users/mbed_official/code/mbed/builds/97feb9bacc10 \ No newline at end of file