Roomba Dance Fix - Check Bumper Optical Sensors

If you have the unfortunate but possibly inevitable Rooma dance symptom and before you attempt to follow anis' detailed cleaning procedure as quoted in my previous Roomba post, try cleaning the optical sensors for the bumper first!

Not to be confused with the cliff sensors that are located at the bottom of the bumper itself, there are two pairs of optical sensors which are on the main chassis and work together with the bumper to detect that the robot has reached an obstacle in front.

To start, follow the common procedure to remove four screws inside the bumper, remove the bumper from the chassis by detaching a cable connector inside, and locate a black plastic arm on both sides in the chassis as shown in the following two photos. I've pointed out where the sensors are with big fat arrows.

Roomba bumper left arm

Roomba bumper right arm

Once you have found them, use a wet tissue or wipe to clean the sensors. Then test if the cleaning helps by connecting the bumper's cable back and giving the robot a go.



If it still doesn't work, you may have to try cleaning something else.

If it works for you, here's why. Examine the following photo, which indicates the direction of the plastic arm when it is actuated by some contact on the bumper. As long as the sensors cannot "see" through the hole in the arm (in this case due to the dirt covering them), the robot would think that it has hit an obstacle and tries to turn itself away from that side. Ergo, Roomba dance.

Roomba bumper arm movement direction

Now, put the screws back inside, take your Roomba for a spin, and do the chicken dance yourself.

Technorati Tags: roomba, roomba dance, circle dance, optical sensor

Nokia N78 Packet Data Connections

For those who have the Nokia N78 mobile phone and are having difficulties getting packet data connections over GPRS and 3G, I have found one solution. This problem happens after you have downloaded or configured your operator's access points (Menu -> Tools -> Settings -> Connection -> Destinations) and when you want to connect for web browsing or sending multimedia messages (MMS). The phone will show a message saying "connection not available".

Solution is simple. Go to Menu -> Tools -> Settings -> Connection -> APN control. A message will say "Reading content from SIM card". After that, it should display another message "Connections restrictions inactive". If it does not, go to Options -> Deactivate restrictions. Exit all the way back to the standby display and try web browsing or sending a MMS.

The help page for "Restrict connections" is described:

With the access point control service, packet data connections from your device may be restricted to certain access points only.

Your SIM card may not support the access point control service. Contact your service provider for more information.

Let me know if this works for you.

The following is a good site to be updated on Nokia software updates, which recently announced firmware version 12.046 for the Nokia N78. This release includes performance improvements for softkey selection, Bluetooth stability, video playback, e-mail sending and alarm clock functions.

<URL:http://europe.nokia.com/A4577225>

Technorati Tags: nokia, n78, nokia n78, mobile phone, packet data, data connection, connection not available, access point, apn control, connection restrictions