Archive for May, 2007

USB graphics LCD controller

Friday, May 11th, 2007

Another project in development is a USB interfaced controller board for graphic displays. As it uses the S1D13700 controller from Epson it can support a maximum resolution of 640×240 in 1 bpp mode. Also supported by the Epson controller are 320×240 max at 2 bpp and 240×160 max at 4 bpp. This controller can be used with controllerless LCD panels with 4-bit interface. Included on the board are two common FFC connectors used with these displays and a 2.54mm pitch header for custom wiring. Also included is a DC/DC converter for generating the contrast voltage these displays usually need.

Rendered image of the first prototype


First prototype assembled


Controller board used in an experiment with a transparent LCD


The project was developed further and more information is available here:

Cinch ModICE

Wednesday, May 9th, 2007

While browsing the Mouser catalog today I noticed something new that I hadn’t seen before. The Cinch ModICE enclosure with integrated connectors.


I remember seeing something similar from Deutsch but never seen any pricing for them or a place where I could easily buy it.

Adding together all the parts needed to build a complete system with this ModICE isn’t cheap either but might be worth considering compared to getting a separate enclosure and sealed connector and then figuring out how to make everything fit together with the PCB in the enclosure.

Cheap USB joystick taken apart

Tuesday, May 8th, 2007

I haven’t taken apart a joystick in over 10 years so I wasn’t exactly sure what to expect to find inside a cheap USB joystick these days. The victim here is a commonly available Logitech Extreme 3D Pro joystick.


From different angles

logitech_joystick_1.jpg logitech_joystick_2.jpg logitech_joystick_3.jpg logitech_joystick_4.jpg logitech_joystick_5.jpg



logitech_joystick_7.jpg logitech_joystick_8.jpg

X- and Y-axis potentiometers

logitech_joystick_10.jpg logitech_joystick_11.jpg
Nothing special here. Potentiometers as a voltage divider. The voltage going to the potentiometers is about 4 V and the output between 0.4 V and 3.6 V. The potentiometers have been attached straight to the ends of the axles of the mechanism without any gears and the handle moves about +-18° so the potentiometers move only about 1/10 of a full circle. Can’t predict very long life for small cheap potentiometers this way. Potentiometers could be replaced with better potentiometers or with hall effect sensing.

Handle buttons


The switches for the buttons and the 8-way hat look to be a common type so they could be replaced with better quality switches when they break.

Overall it doesn’t look as bad as I thought it might be. The potentiometers might not last long but if replaced with hall effect sensing for example things should be better. Also the mechanism in the base is about 7 x 7 cm so it could be placed in a smaller enclosure.

USB interface for a Noritake -3900 series graphical VFD

Tuesday, May 8th, 2007

Another little device that I made earlier this year is a USB interface board for a Noritake -3900 series graphical VFD display.

Here we have the interface connected to a GU256x128C-3900 display.


This interface is useful for easy communication and fast update speeds allowing for example animation when using these displays with a PC. These are also available for sale if someone needs one. The USB interface boards have been used with the 256×128 and 256×64 sizes for now but other resolutions from the 3900 series are also possible if needed.