Read data from the 9 DOF Razor IMU via Arduino board.

After several problems with the original 9DOF Razor IMU board, I have finally got a board with no functional problems or bugs. The challenge we had to work around then was how to read the data from the board? So I decided do some research and found in this blog that there was a simple way to read data using the Arduino Duemilanove connected to the 9DOF Razor IMU board without requiring any additional cable as shown in Figure 1.

Figure 1

The sketch to read the data from the 9DOF Razor IMU via Arduino Duemilanove is very short and simple as shown below.

/*

Read data from the 9DOF Razor IMU board via arduino duemilanove board.

1. Upload this Sketch to the Arduino board
2. Disconnect the USB cable from the PC. 
3. Connect the jumper wires between the two boards
   according to the following table:

9DOF Razor IMU | Arduino Duemilanove
---------------|--------------------
TX0............|TX1.................
RX1............|RX0.................
3.3V...........|3V3.................
GND............|GND.................
---------------|--------------------

4. Connect again the USB Cable to the PC.
5. Open Serial Monitor.
6. Send the character '1'.
7. Send the character '0' to view the 9DOF Razor IMU Menu.

*/

void setup() {
  Serial.begin(38400);
}

void loop() {
  if(Serial.available()) {
    Serial.print(Serial.read(), BYTE);
  }
}

After doing the upload of the sketch, and open the Serial Monitor, send a character between '1' and '5' followed by a '0' then a menu is shown (Figure 2).

Figure 2

In the menu there are have five options: [1] Accelerometer (ADXL345), [2] Magnetometer (HMC5843), [3] Gyroscope (LPR530 and LY530), [4] Raw and [5] Self Test. For example, if you choose the option "1" and if you move the 9DOF Razor IMU board in any direction you will see on the Serial monitor the variation of the values for the aceleration

The following video shows the 9DOF Razor IMU board connected to the Arduino board working hard (Sorry for the bad video quality!). Notice menu of the 9DOF Razor IMU board on the monitor of the laptop.

But unfortunately this sketch does not fit what I want. With the Arduino Duemilanove only can be used a single Serial connection at a time. However, that problem can be solved by using software libraries. One of the libraries is the SoftwareSerial library which allows the serial communication on any of the Duemilanove's digital pins. But, because it's not supported by hardware, the library has a few limitations. The other library is the NewSoftSerial library that emulates an additional serial port, allowing you to communicate with another Serial device. However, there is another Arduino board where you can use more than one connection, which is the Arduino Mega. With the Arduino Mega is possible connect more three Serial devices. The last solution is more robust but, requires a further investment in a new board. So I'll have to take a look in the Arduino board clones.