Hexiwear
Simple temperature and humidity program example for Hexiwear featuring UART
Fork of
HTU21D
by 
Alex Lipford
This project demonstrates the use of the HTU21D temperature and humidity sensor embedded in Hexiwear
Open a Hyperterminal tool on your computer and connect it to the "mbed Serial port (COMxx)" with Baud rate "9600bps"
Compile the project and copy the binary "Hexi_Humid_Temp_Example_HEXIWEAR.bin" in the DAP-LINK drive from your computer file explorer Press the K64F-RESET button on the docking station to start the program on your board
Every 500ms the value of the Temperature and Humidity will be displayed in the Hyperterminal window and the LED will blink Green
Revision 2:4fd07be6bad8, committed 2014-10-19
- Comitter:
- alipford3
- Date:
- Sun Oct 19 19:27:19 2014 +0000
- Parent:
- 1:d7568a103ef5
- Child:
- 3:caccf1879f14
- Commit message:
- An updated, basic library to interface with the HTU21D temperature and humidity sensor
Changed in this revision
| HTU21D/HTU21D.cpp | Show annotated file Show diff for this revision Revisions of this file |
| HTU21D/HTU21D.h | Show annotated file Show diff for this revision Revisions of this file |
--- a/HTU21D/HTU21D.cpp Sun Oct 19 18:24:53 2014 +0000
+++ b/HTU21D/HTU21D.cpp Sun Oct 19 19:27:19 2014 +0000
@@ -1,14 +1,14 @@
/**
- * @author Alan Lai & Nelson Diaz
- * The Georgia Institute of Technology
- * ECE 4180 Embeded Systems
+ * @author Alex Lipford
+ * Georgia Institute of Technology
+ * ECE 4180 Embeded Systems Design
* Professor Hamblen
- * 03/28/2014
+ * 10/19/2014
*
* @section LICENSE
* ----------------------------------------------------------------------------
* "THE BEER-WARE LICENSE" (Revision 42):
- * <alanhlai91@gmail.com> wrote this file. As long as you retain this notice you
+ * <alexlipford@gmail.com> wrote this file. As long as you retain this notice you
* can do whatever you want with this stuff. If we meet some day, and you think
* this stuff is worth it, you can buy me a beer in return.
* ----------------------------------------------------------------------------
@@ -45,11 +45,11 @@
tx[0] = TRIGGER_TEMP_MEASURE; // Triggers a temperature measure by feeding correct opcode.
i2c_->write((HTU21D_I2C_ADDRESS << 1) & 0xFE, tx, 1);
- wait_ms(50);
+ wait_ms(50); // Per datasheet, wait long enough for device to sample temperature
// Reads triggered measure
i2c_->read((HTU21D_I2C_ADDRESS << 1) | 0x01, rx, 2);
- wait_ms(50);
+ wait_ms(1);
// Algorithm from datasheet to compute temperature.
unsigned int rawTemperature = ((unsigned int) rx[0] << 8) | (unsigned int) rx[1];
@@ -86,7 +86,7 @@
tx[0] = TRIGGER_HUMD_MEASURE; // Triggers a humidity measure by feeding correct opcode.
i2c_->write((HTU21D_I2C_ADDRESS << 1) & 0xFE, tx, 1);
- wait_ms(1);
+ wait_ms(16); // Per datasheet, wait long enough for device to sample humidity
// Reads triggered measure
i2c_->read((HTU21D_I2C_ADDRESS << 1) | 0x01, rx, 2);
--- a/HTU21D/HTU21D.h Sun Oct 19 18:24:53 2014 +0000 +++ b/HTU21D/HTU21D.h Sun Oct 19 19:27:19 2014 +0000 @@ -1,14 +1,14 @@ /** - * @author Alan Lai & Nelson Diaz - * The Georgia Institute of Technology - * ECE 4180 Embeded Systems + * @author Alex Lipford + * Georgia Institute of Technology + * ECE 4180 Embeded Systems Design * Professor Hamblen - * 03/28/2014 + * 10/19/2014 * * @section LICENSE * ---------------------------------------------------------------------------- * "THE BEER-WARE LICENSE" (Revision 42): - * <alanhlai91@gmail.com> wrote this file. As long as you retain this notice you + * <alexlipford@gmail.com> wrote this file. As long as you retain this notice you * can do whatever you want with this stuff. If we meet some day, and you think * this stuff is worth it, you can buy me a beer in return. * ----------------------------------------------------------------------------