Fried chicklet

[karin l.]

We have a USB chicklet to convert the USB joystick to serial (Logitech Extremem 3D Pro). It was working fine until today, when we noticed in Dashboard Viewer that the joystick was behaving erratically (without touching the joystick, the three axes started at 60 and dropped about 5 per second).

We're fairly certain that this isn't a calibration error since (a) we weren't touching the joystick, and (b) the old serial joystick worked fine. We also realized that the batteries we were using for the chicklet drained very quickly.

We plugged a multimeter into the chicklet alone (not connected to the robot or joystick in any way) and it still drained power at a few volts every minute without using it. Therefore, we have concluded that there is probably a short circuit.

Is anybody else experiencing similar problems? Additionally, does anyone know what we can do to fix it or diagnose the problem further? Any help is welcome.

[joshR515]

We are using them two. We have found out that if the battery goes below 6.5 volts then the joysticks start going down. How ever we have not hooked them up with a battery. I have created a circuit that used a comaritor to turn on the LED when the battery reaches 6.5 volt. We are going to use the 7.2 volt RC battery packs that are used for back up batteries providing 1800-2000 Mah.

[karin l.]

We completely understand this. We are using a 7.2 volt battery which is at 7.2 volts. However, upon connection to the chicklet, the light on the chicklet turns red and the battery drains quickly, indicating a short. This happens with the joystick unplugged as well as with the joystick plugged in. It is almost certainly a fault with the chicklet, maybe one caused by us, but the chicklet seems in fine condition with no shorts or problems with the board.

[Mike Copioli]

Originally Posted by karin l.

We plugged a multimeter into the chicklet alone (not connected to the robot or joystick in any way) and it still drained power at a few volts every minute without using it. Therefore, we have concluded that there is probably a short circuit.

Are you using a battery? If so, it is dead. To prove this, connect a wall DC power supply(9V) to the Chicklet. If the Chicklet exhibits no abnormal behavior when using the power supply, then your battery is dead. The Chicklet requires a minimum 7.2V-9V supply. Another test you can perform is to connect a current meter in series between the Chicklet and the battery pack. The Chicklet should draw between 50 or 60mA without a device(joystick) attached. Our testing shows that when used with a FULLY CHARGED backup battery, the life is about 4 hours. Measuring the voltage drop is not an accurate way to asses if there is a short. The results will be the same if you are using a dead battery. You should always ensure that your battery is fully charged before using it with the Chicklet. If you have any further issues contact me at mcopioli@crosstheroadelectronics.com

[Mike Copioli]

Originally Posted by joshR515

We are using them two. We have found out that if the battery goes below 6.5 volts then the joysticks start going down. How ever we have not hooked them up with a battery.

Yes. The Chicklet requires a power source of at LEAST 7.2 volts. This is diplayed on the IFI websight under specs.

Originally Posted by joshR515

I have created a circuit that used a comaritor to turn on the LED when the battery reaches 6.5 volt. We are going to use the 7.2 volt RC battery packs that are used for back up batteries providing 1800-2000 Mah.

This is not necessary if you ensure that the battery is fully charged before competition. We did our testing with a 700mah battery and got over 4 hours out of it.

[Mike Copioli]

Originally Posted by karin l.

We completely understand this. We are using a 7.2 volt battery which is at 7.2 volts. However, upon connection to the chicklet, the light on the chicklet turns red and the battery drains quickly, indicating a short. This happens with the joystick unplugged as well as with the joystick plugged in. It is almost certainly a fault with the chicklet, maybe one caused by us, but the chicklet seems in fine condition with no shorts or problems with the board.

A 7.2 volt battery is not 7.2 volts when it is fully charged. It is closer to 9V. Nominally, it should be at about 8-8.5v when fully charged. If your battery is a 6 cell NICAD and it is measuring 7.2 volts, it needs to be charged. The Chicklet is an electronic device just like the camera and the R/C if they do not get the proper voltage they cannot function properly.