Compass to OOPic Example

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Introduction
Circuit Schematic
Source Code

Introduction

In this example, an OOPic module uses a Devantech Compass Module to gain orientation information. The OOPic reads a 1-byte, 255-step compass reading representing one full revolution in headings from the compass module.

The compass module is connected to the OOPic via the OOPic's built-in I2C bus. You will also need a LED and a 330ohm resistor for this example. To make the connections, do the following steps in the order:

Connect pin1 (5v) to pin22 (+5v) on the OOPic 40 way connector.
Connect pin2 (SCL) to pin3 (LSCL) on the OOPic 40 way connector.
Connect pin3 (SDA to pin1 (LSDA) on the OOPic 40 way connector.
Connect pin9 (0v) to pin2 (GND) on the OOPic 40 way connector. Leave the other pins unconnected for now.
Connect the LED cathode (shorter leg) to pin 24 on the OOPic.
Connect the LED anode (longer leg) to the 330R resistor.
Connect the other end of the 330R resistor to pin28 (I/O 30) on the OOPic.

Contents

Circuit Schematic

Contents

Source Code

' compass-2.osc ' CMPS01 Compass -> OOPic Example Code ' ' This reads compass register 1, an 8 bit value representing the bearing ' as a 0 - 255 value. ' To read the value in degrees, change the Bearing from oByte to oWord ' and the .Location to 2, and the .Width to cv16bit ' Registers 2,3 are 0 - 3599 representing 0 - 359.9 degrees ' Dim Compass As New oI2C ' Create the compass objects Dim Led As New oDio1 ' Dim Bearing as new oByte ' Somewhere to store the reading Sub main() Setup ' Setup the LED and compass Do Compass.Location = 1 ' Address of single byte bearing Compass.Width = cv8bit ' Compass Data is 1-byte wide. Bearing = Compass.Value ' Get it If( (Bearing<5) Or (Bearing>250) ) Then Led = 1 Else ' Light the Led if within 5 degrees of north Led = 0 End If Loop End Sub Sub Setup() Compass.Node = 96 ' Decimal of Hex address 0xC0 shifted right by 1 Compass.Mode = cv10bit ' I2C mode is 10-Bit Addressing. Compass.NoInc = 1 ' Don't increment Led.IOLine = 30 ' Pin 28 on 40 way connector Led.Direction = cvOutput ' End Sub

Revision History:

2001-07-16: Example Created.