Nuts & Volts - January 2005

Tech Forum

Can anyone suggest a means to securely transmit data from the X10 cameras to the receivers? External methods are okay, but I suspect tapping inside connections would work best.

#1056

Errol White via Internet

Regarding reading an ADC output from an aperture opening, then advancing film or paper to be cut, I understand the ADC and the electronics. I know little about programming; could this be done with a PIC?

#1057

Arthur Williams Ashland City, TN

I'm using an LM3909 in a circuit to control a flashing red and green light on a model railroad. Is there a pin-for-pin replacement for it? If not, is there one that isn't pin-for-pin?

#1058 R. Thompson

Richmond, MO

ANSWERS

[20410 - February 2004]

I have a surplus VFD display module, but no specs. It looks like one of those large cash register displays that's mounted on a pole. Inside is a pair of Futaba M202LD01DA vacuum fluorescent displays. The interface cable has eight pins where 20 VDC power is applied and an RS-485 serial interface is used to talk to the modules.

I, too, have one of these displays. I talked to the engineers at Futaba, who said that this display unit is a customer-proprietary product and no information is available.

They did allude to the fact that the ROM uses a completely unorthodox pattern for addressing the display. I’ve searched the Internet without success and even pulled a few strings at Futaba with the same results. Sorry.

Ed Edmondson, Jr., Ph.D.

Alamosa, CO

JANUARY 2005

[3046 - March 2004]

Does anyone have a simple circuit that uses an IR sensor to trigger a camera? I'd like to snap pictures of the nocturnal visitors in the backyard of my country home.

#1 A simple solution — though perhaps expensive — is to buy a Stealth Cam. Sportsman's Guide ( www.Sportsmansguide.com or 800-882-2962) has two models on their website These units are self-contained, weatherproof 35 mm cameras. They use standard 35 mm film slides — print or black-and-white. They sense motion and take pictures with flash. They have options for how many pictures at a time and how long to delay between pictures. The cheapest is part number WX2-73967 at $79.97.

Jim Schmidt Deer Lodge, MT

#2 Buy an IR floodlight ( motion-sensing flood light) unit at Home Depot. Remove the floodlight lamp sockets and wire a relay with a 120 VAC coil in place of one of the sockets. Control the camera with the relay contacts. The cost is about $10.00 for the sensor and $5.00 for the relay.

Anonymous via Internet

[50410 - May 2004]

I have an old keyboard (from a Wyse 2108 computer, vintage 1988 or so). It has a fantastic touch that I have been unable to find in modern keyboards. I've tried all 24 possible combinations of the four signals in an adapter cable, but none of them works. I'm guessing that there is some other incompatibility preventing this old keyboard from working on a more modern computer.

The Wyse 2108 is not a computer, but a terminal. What you can do is use it at such by installing Linux on your PC and connecting the Wyse to a serial port that is

configured as a terminal line. Unfortunately, you can only use shell commands on your terminal and not all the fancy graphics environments and applications that are available for Linux nowadays.

Therefore, a better solution for your question is to get an old PS/2 or USB keyboard for free somewhere in the garbage or at a flea market. Each keyboard has a controller that converts keys connected in a matrix to the PS/2, USB, or other bus protocol. (The first IBM-PC keyboards back in the 1980s were equipped with the 8048 microcontroller.) Your task now is to connect the Wyse terminal keys to the matrix of the controller which was obtained from the “garbage” keyboard.

Gerrit Polder The Netherlands

[9042- September 2004]

I am trying to find info on a kit that was offered back in Radio Electronics Magazine called the HyperClock. It was offered by an outfit named SkiTronix around 1991. I built one back in high school and it has just now failed. I cannot locate the schematics or magazine issue that featured it. Searching the web has not yielded anything.

This was answered by many N&V readers, but William Richter was the first to supply a photocopy of the actual article to Rich White. Thanks, William! — Editor Dan

[10046- October 2004]

I just installed new AT & T 2.4 GHz phones: a base and three handsets. Now — if all the phones are in their charging cradles — I get big, double horizontal bars on TV channels 4 and 5 and buzz on my portable FM radio. If the phones are out of their cradles, everything is okay.