I'm surprised that this thread has not included mention of Kicad (a free (as in Free Beer and Free of License restrictions)), a suite of ECAD programs. Far better than Eagle (IMO - I never really "got" Eagle) and nearly as simple as Design Spark, without the vendor tie-in.
The homebrew PCBs Yahoo! group also has a wealth of information and knowledgable people. <http://groups.yahoo.com/group/Homebrew_PCBs> who all do toner-transfer, positive and negative photoetch, isolation milling, and etching with FeCl, CuCl, Ammonium Persulphate, HCl/H2O2, strong coffee, ...
I do an occasional board, but nowhere near as many as I'd like. Kicad, toner transfer (with inkjet paper), HCl/H2O2, hand solder are my usual toolchain.
@dhlocker1, thanks for that info and link, I'll bounce over there when I have a second and take a look. Forums like that can often save you hours of experimentation and sometimes tears (as in wailing and gnashing of teeth :-) when you have problems with an existing tool or are trying to select a new one.
I must say that I didn't pursue the photo technique much further, soon reverting to good old ink & brush - at least as long as spare time for hobby lasted, that is, not for long.
Now in my daily job as an EE, sometimes during the prototyping stage of a new project when I need small PCBs made in short time and low cost, I have them made at a CNC mill service. Results are excellent, down to 8mils trace width / clearance.
Admittedly, tne new DIY techniques as toner transfer, P&P, and the like, are very intriguing. I ought to give them a try some day.
@David : I have always run Tiny Cad with VeeCad and whilst the two do not forward and back anotate they seem to co-exist well.
I have just downloaded FreePCB and this is supposed to link with Tiny Cad output, so I shall now be trying this out. FreePCB is also linked to a Free router software so all this will be in the melting pot with me over the nex few weeks.
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.