[tech] temperature logging

[Davyd Madeley]

Quoting Trent Lloyd <lathiat at bur.st>:

> On Mon, Jul 11, 2005 at 10:05:28AM +0800, Adrian Chadd wrote:
>>
>> amusingly, this is about the kind of thing I was going to build
>> tomorrow using an AVR. It shouldn't take too much effort to make
>> an 8 port input/8 port output device. Temperature sensoring is
>> available, as the AT90S8535/ATMega8535 has 8 ADCs.
>>
>> Tis up to you all. I think electronic projects are fun. :)
>
> Thats what I thought but davyd seems to think using a premade board is
> better cus its cheaper and wasted effort to re-invent the wheel. :)

The electronics involved in this project was correctly biasing the temperature
IC. You could not build this board for what it costs, not using proper
connectors, regulation circuitry, protection circuitry and the
microcontrollers. This was a rather easy to set up solution, and works
yesterday, not tomorrow.

The first rule of engineering is to see what's already been engineered, 
and use
it. This is awfully similar to the first axiom of programming "Good coders
code, Great coders reuse", which is also something that makes a lot of UCCans
simply good coders.

For reference (from memory), the board contains a HC11, a TTL buffer 
circuit, a
9->5V regulated power supply, and power diodes to protect against reverse
polarity. When you're googling for a version to copy, this is probably a good
reference design. It's really more of a software project, writing asm is
software I'm afraid, not electronics.

--d