Direction Finder

2 Axis Solar Tracker Circuit

The sun trucker uses a combination of three photoresistors R7, R8 and R9, to ensure that the circuit will follow the sun during the day, but stop working at night time. Make this circuit 2 times to have 4 Axis move, by using 2 motors...

Digital Compass for PC

The digital navigation PC board may be configured for a number of navigation functions, see figure 1. It may be made into a simple visual digital compass, or a microcontroller based compass. The microcontroller based compass can be used for mobile robotics or a PC based compass. The sensor used on the PC Board is the 1490 digital compass manufactured by Robson Company, see figure 2. This sensor is a solid-state Hall effect device. It is sensitive enough to detect the Earth's weak magnetic field...

Electronic LED compass

This is a compass circuit based at AT90S2313. The output drives 8 LEDs to indicate the different horizon directions...

Variable GPS Jammer

A low cost device to temporarily disable the reception of the civilian coarse acquisition (C/A) code used for the standard positioning service (SPS) on the Global Positioning System (GPS/NAVSTAR) L1 frequency of 1575.42 MHz. This is accomplished by transmitting a narrowband Gaussian noise signal, with a deviation of +/- 1.023 MHz, on the L1 GPS frequency itself. This technique is a little more complicated than a simple continuous wave (CW) jammer, but tends to be more effective (i.e. harder to filter) against spread spectrum based radio receivers. This device will have no effect on the precise positioning service (PPS) which is transmitted on the GPS L2 frequency of 1227.6 MHz and little effect on the P-code which is also carried on the L1 frequency. There may be a problem if your particular GPS receiver needs to acquire the P(Y)-code through the C/A-code before proper operation...

Detects and counts inputs and outputs. Photoelectric detectors are usually unidirectional, i.e. they are able to detect when someone enters a particular area but not when leaves it. On the contrary, a system able to detect movement in both directions could be useful to control shops, rooms etc. If installed in a shop it could allow to know if all customers entering the premises have left them at the end of the day. Or, at home, it could be used to switch on the light (or any other electric device) when one enters the room and to switch off the electric device when he or she leaves it. Suited to control Lamps, Household Appliances etc...

The µPC8211TK, µPC8215TU, and µPC8226TK are silicon germanium (SiGe) microwave monolithic integrated circuits (MMIC) designed as low noise, high-gain amplifiers for GPS and mobile communications. These ICs are manufactured using our 50 GHz fmax UHS2 (Ultra High Speed Process) SiGe bipolar process. The use of these three devices in evaluation boards implementing LNAs (Low Noise Amplifiers) at 1.575 GHz GPS is described in this document...

Frequency accuracy has been a topic of special interest to many amateurs and experimenters since the early days of radio. Until recently, the best frequency standard available to most hams was a crystal oscillator carefully adjusted to zero-beat with a station of known frequency, such as WWV...

This GPS receiver is powered by 2 AA batteries. They are only strong enough for the GPS to stay on for about two hours, and this seems like quite a waste. I would like to be able to use a larger battery, and sometimes even an AC adapter...

When designing an EIA-485 control bus to link widely separated machinery and process controllers, devising a scheme to control the repeaters can be one of the more awkward tasks. In long buses, bus segments are joined with repeaters if the distance exceeds the maximum allowed by one cable segment...

The goal was to make a compass sensor compatible with the RCX and have it only take one sensor input port to take a compass reading. We decided to use a Dinsmore analog compass part that has two outputs that need to be combined to determine the direction the compass is pointing. With our design, it takes two readings by the RCX to get one complete reading from the compass sensor...

The sensor used on the PC Board is the 1490 digital compass manufactured by Robson Company, see figure 2. This sensor is a solid-state Hall effect device. It is sensitive enough to detect the Earth`s weak magnetic field. When rotated it can display the position of the four cardinal points on a compass, North (N), South (S), East (E) and West (W)...

For the Garmin 45, GPS II, and some other Garmin units, there is a set of power & data connector/harnesses available. (Ham Radio Outlet and West Marine sell one cable only for $40, or the cable & cradle for $65, approximately.) However, the leads are long. Rather than cutting them down for our use, we recommend preparing the end according to the specification shown below, and then coiling the excess cable...

This is a project that I started back late 2003 when I just starting to learn PIC programming. I wanted to building something that actually did somthing useful. This project is based on a PIC16F84. I actually came up with this idea and then after doing some searching I found that a few people had the same idea. But, I wanted to build my own that I could call mine, developed by me...

The GPS interface can be fed in 2 ways: with a stabilized 5V supply or with a 10 to 25V unregulated DC supply. In both cases the power is fed into the RJ45 connector on point 8. Pin 7 is DC ground. The power supply current is first secured with a slow 315mA fuse (in socket). Then there is a Transzorb device to ground. This device is a short-circuit for reverse polarity voltages and for voltages above 27V. It causes the fuse to blow and in doing so, protecting the other electronics and GPS module...

Some Garmin GPS receivers are capable of running off external power ranging up to +32VDC or more, whereas others can only accept a maximum of +8VDC...