From a9050e6dc5c04efe2b2731ac5370dcf3554b839c Mon Sep 17 00:00:00 2001
From: Stephen Birarda <commit@birarda.com>
Date: Wed, 27 Feb 2013 14:45:14 -0800
Subject: [PATCH] read from magnetometer on SDA, SLC
---
hardware/head_hand/head_hand.pde | 50 ++++++++++++++++++++++++++++----
1 file changed, 44 insertions(+), 6 deletions(-)
diff --git a/hardware/head_hand/head_hand.pde b/hardware/head_hand/head_hand.pde
index 844f352e56..920f1428ef 100644
--- a/hardware/head_hand/head_hand.pde
+++ b/hardware/head_hand/head_hand.pde
@@ -5,6 +5,8 @@
//
// PIN WIRING: Connect input sensors to the channels in following manner
//
+// SDA: Magnetomer SDA
+// SDL: Magnetomer SDL
// AIN 10: Yaw Gyro (shaking your head 'no')
// AIN 16: Pitch Gyro (nodding your head 'yes')
// AIN 17: Roll Gyro (looking quizzical, tilting your head)
@@ -12,11 +14,16 @@
// AIN 19: Up/Down acceleration (sitting up/ducking in front of your monitor)
// AIN 20: Forward/Back acceleration (Toward or away from your monitor)
+// include HardWire for I2C communication to Magnetomer
+#include <HardWire.h>
+
#define NUM_CHANNELS 6
#define MSECS_PER_SAMPLE 10
#define LED_PIN 12
+const int COMPASS_ADDRESS = 0x42 >> 1;
+
int inputPins[NUM_CHANNELS] = {10,16,17,18,19,20};
int LED = 0;
@@ -26,8 +33,12 @@ unsigned int time;
int measured[NUM_CHANNELS];
float accumulate[NUM_CHANNELS];
+bool readFromMag = false;
+
int sampleCount = 0;
+HardWire Wire(1, I2C_FAST_MODE);
+
void setup()
{
int i;
@@ -36,6 +47,7 @@ void setup()
measured[i] = analogRead(inputPins[i]);
accumulate[i] = measured[i];
}
+ Wire.begin();
pinMode(BOARD_LED_PIN, OUTPUT);
pinMode(LED_PIN,OUTPUT);
time = millis();
@@ -44,11 +56,22 @@ void setup()
void loop()
{
int i;
+ int compassReading;
+ bool magTransmit = false;
sampleCount++;
for (i = 0; i < NUM_CHANNELS; i++) {
accumulate[i] += analogRead(inputPins[i]);
}
+
+ if (readFromMag && magTransmit == false) {
+ // get current absolute magnetometer value
+ Wire.beginTransmission(COMPASS_ADDRESS);
+ Wire.send('A');
+ Wire.endTransmission();
+ magTransmit = true;
+ }
+
if ((millis() - time) >= MSECS_PER_SAMPLE) {
samplesSent++;
time = millis();
@@ -58,7 +81,7 @@ void loop()
SerialUSB.print(" ");
accumulate[i] = 0;
}
-
+
if ((samplesSent % 100 == 0) && (samplesSent % 150 == 0)) {
LED = !LED;
digitalWrite(LED_PIN, LED);
@@ -72,10 +95,25 @@ void loop()
else
SerialUSB.print("0");
- SerialUSB.println("");
+ SerialUSB.print(" ");
sampleCount = 0;
+
+ if (readFromMag) {
+ // send the absolute value from the magnetomer
+ Wire.requestFrom(COMPASS_ADDRESS, 2);
+
+ if (2 <= Wire.available()) {
+ compassReading = Wire.receive();
+ compassReading = compassReading << 8;
+ compassReading += Wire.receive();
+ compassReading /= 10;
+ SerialUSB.print(compassReading);
+ }
+ }
+
+ SerialUSB.println("");
+
+ // reset the magnetomerTransmit to false to prep it in next loop
+ magTransmit = false;
}
-}
-
-
-
+}
\ No newline at end of file