- The sensor should be set up with the coarse gain set as low as possible, but will still allow good positive touches. This means that there will be as low a level of noise as possible in the system.
- The sensor always has a low level of background noise. The setup of the sensitivity and the press threshold is to allow the sensor to differentiate between background noise and true touches.
- Sometimes the mouse will move around randomly of its own accord. This is due to spurious noise in the system and can be caused by a number of things. In this case disconnect the cable to the PC and uncheck the "Enable Selected Control" box in the output tab of MA7/8. You will then be able to work with the sensor until the sensitivity setup is working in a correct manner.
Things to look for it there is too much noise in the LCD/touchfoil™ combination
- An Air gap of 8mm or more will be required between the LCD panel and the touch sensor.
- Where visualplanet have experience of a particular LCD we will share that information. In other cases the only way to discover the distance is by trial and error.
- If the LCD is too close then the resulting noise interference with the touchfoil™ will result in spurious random mouse movements.
- In all cases the earth cable provided with the touchfoil™ controller MUST be connected to the metal CASE/CHASSIS of the LCD. The whole setup should be very well grounded.
- Ensure Laptops are connected to the mains. If the earth of the system is floating random noise may occur.
- Mains conditions vary from one location to another. Visualplanet have had examples of touchfoil™s being on one floor in a building and being noisy, and on a different floor being perfectly OK.
- The Press threshold in the driver is set too close to the Finger Pressure. Either the Press Threshold must be moved to the right slightly or the Coarse Sensitivity must be reduced so that any background noise is not seen as a touch.
- Check the routing of the cables. Isolate the USB/Serial cable away from other cables eg. VGA, power or data cables.
- The touchfoil™ may be too close to a power source of some kind or there may be other electronic devices nearby.
- Try to locate the controller board away from power supplies, printers, inverters or any other electronic components in your in your unit.
- If there is a store theft detection system nearby (RFID) then this may cause interference. It can be effectively shielded with a metal shield such as aluminium foil.
- To check the cause of the noise try to move the touchfoil™ to another location with a known working setup (where possible) and install it there.
- When installing the touchfoil™ to a unit located in a metal/alluminium frame please ensure the frame is grounded to avoid any unnecessary interference.
- The store clothing tag detector near entrances causes electrical noise and can stop a touch system working if too close. A grounded metal plate between the two systems will prevent any problems.
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