A watering controller that can be home networked

Step 2 Making the board

To make the PCB, I used press-n-peel and toner transfer, as I do for all of my projects.

Essentially, I print the PCB layout onto some toner transfer paper.  I use Press-n-peel Blue, which costs a bit of money, but is beautifully reliable.  That is then laminated onto some clean PCB stock the paper is removed, and the layout is touched up using a permanent marker where there are dust spots.

Then I etch the board using a mixture of 120mL Hydrochloric Acid, and 240mL of Hydrogen Peroxide (20%) - The excess copper is dissolved in about 5 minutes, then the board is thoroughly washed to ensure that all acid is removed.

Then I scrub the toner material off the board using steel wool, and protect the board using a solder through spray lacquer.

Finally, I drill the board using my trusty Dremmel (Which has been working great for 20 years)

I have made hundreds of boards using this method, and it works really well.  Just be very careful using acids - wear eye protection, old clothes, and gloves.  And make sure that you protect your stainless steel laundry sink.  I protect mine by filling it with 10Litres of water, that way when a couple of drops of acid end up in it while I am rinsing off a board, it is diluted by lots and doesn't damage anything.    :-)