Introduction.

Note that the Weather PIC kit consists of parts suitable for mounting on a solderless prototyping breadboard.

I am hopeful some kind person will offer to develop a PCB and provide us with the various files the PCB shops require to produce printed boards. We just do not have the expertise to do this.

But, in the mean time, the following abbreviated description may aid in helping you determine the level of difficulty. Clearly, the actual documentation is far more detailed.

Overview of Assembly.

Main Processor. PIC16C558. 18-pin DIP. Connect power and ground. Place a 10 pin resistor SIP network on each side of the processor. Connect the 4.0 MHz resonator (three leads).

RS232 Interface. DS275. 8-pin DIP. Connect power and ground. Connect to main PIC (two leads). Connect to PC Com Port (three leads).

DS1820 Digital Thermometer. Connect to processor (two leads).

Relative Humidity. Run two twisted pairs to remotely located Fascinating RH PCB.

Barometric Pressure and User A/D. Install A/D (8-pin DIP). Connect power and ground. Connect to main processor (three leads). Connect power and ground to MPX4115. Connect output to A/D (one lead).

Wind Speed and Gust. Install PIC12C508 identified as WIND (8-pin DIP). Power and Ground. Connect to processor (two leads). Install twisted pair to anemometer. Install debounce circuit (one resistor and capacitor).

Rainfall Accumulation. Install PIC12C508 identified as RAIN (8-pin DIP). Power and Ground. Connect to processor (two leads). Install twisted pair to remote tipping bucket. Install debounce circuit (one resistor and capacitor).

Wind Direction. Install A/D (8-pin DIP). Power and ground. Three leads to processor. Run three twisted pairs to remote wind vane.

Done! Now, knock your socks off writing amazing software.

Running the twisted pairs will of course, require time. But, cable pairs must be run even if you purchase any system whether it be $300 or $1000.

However, all of the local wiring shouldn't require more than two hours.

Other Aids.

Our logic probe is supplied with the kit to help you verify you have the appropriate signals at various points during the assembly.

Once you get the main processor and RS232 interface going, you may use HyperTerm or Procomm Plus or a dumb terminal to verify results.

A 7805 regulator is supplied in case you don't have a five volt supply. Install three terminal regulator. Connect 9 to 12 Volts to one lead, ground to another. Two capacitors. One diode.

This design draws less than 100 mA. Use any wall power unit (wall lump or wall wart) that is rated at anything in the range of +8 to +12 VDC at any current above 100 mA.

If you don't have a solderless breadboard, a small unit from Radio Shack will do. We have a good sized breadboard from Jameco (JE25) for $16.95.

We also have serial cables which we use in the lab where many students must use the same PCs during the course of a day. I mention them, but, all you really need is three leads; TXD, RXD and GRD.

• DB9 female on PC side. Five feet of flex cable. Mates with 10-pin header which plugs into breadboard. ($7.00).
• DB25 female and DB25 male on PC side. Three feet of flex cable. Mates with 26-pin header which plugs into breadboard. ($10.00).

In case you do make an error and blow out a component, they are all available. The most expensive items are the MPX4115 pressure sensor ($20.00) and the 12-bit A/D's ($8.00). You will be okay if you properly connect power and ground.

Finally, if you find that you don't really want the kit, just package it up and return it for a full refund. Our goal is to encourage tinkering, not taking money for things people really can't use.