Wiimote Accelerometer - ADXL335

Hello.

I want to use the accelerometer from the Wiimote (ADXL335) in a different application. I am having problems with the accelerometer sucking too much power from my battery. The battery is draining rather quickly. (I have tried both a 3.3V coin cell battery [CR2016] as well as using a 3.3V voltage regulator from a 9V battery.)

Has anyone tried this?
Does anyone have any suggestions?

Thanks.

The Wii Remote probably has some circuitry that controls power flow to the accelerometer. You should see if you can figure out what that is.

Take a look at the data sheet (pdf file) to see how much power it draws and the recommended circuitry.

[www.analog.com]

It runs off of 3.3 volts and draws 350 uAmps. And the CR2016 has about 50mAh (milliAmp Hours) according to wikipedia. So if that is the case, the CR2016 could run the ADXL335 for 5.9 days. So depending on your application, the CR2016 might be good enough if you don't mind changing the battery every 6 days.

"(50 milliampere * hour) / (350 microamperes) = 5.95238095 days"

In the case of a 9 volt alkaline battery, it has about 565 mAh. And assuming you have a linear regulator to convert 9V to 3.3V, then the 9V battery could run the ADXL335 for 67 days.

"(565 milliampere * hour) / (350 microamperes) = 67.2619048 days"

If you had a switching regular at 70% efficiency, the 9V battery could run the ADXL335 for 128 days.

"((565 milliampere * hour) * 9 V * (70%)) / ((350 microamperes) * 3.3 V) = 128.409091 days"

Anyways it sounds like there is another problem in your circuit causing you to draw too much current from the batteries because the ADXL's power draw is pretty low.

One more note. Say you had 2 alkaline AA batteries in series to get 3 Volts. That would supply about 2700 mAh at 3 volts. And run the ADXL335 for almost a year. Once again the mAh values are coming from wikipedia and in reality change from battery to battery.

"(2700 milliampere * hour) / (350 microamperes) = 321.428571 days"