Schematic for Analog Interface

A commenter asked for the schematic of the analog interface I made using an MPC3008.  I seldom include schematics with my posts for several reasons.  I don’t expect anyone to duplicate exactly what I have done, so if I post anything, it is just partial drawings of the most important concepts.  But the biggest reason is that I almost never create true schematics and I am too busy to do it just for the blog.  Something that I do frequently do is a simple drawing that helps me lay out the components onto the perf board.  Then I use that as my guide when I build the device.  These are seldom complete enough to be useful to others.  In this case, however, the entire circuit is shown.


This is what I created for the analog interface.  The 7-pin header connects to my main circuit board where I have two SPI ports – one with CE0 connected and the other with CE1.  The 3-pin header allows me to select the reference voltage for the MCP3008.  The blocks along the bottom are screw terminals.  See the post Analog Interface for a picture of how this looked when built.

I will probably be pulling this old board out again to experiment with a thermocouple that I just received.  I need it for the flame detection on my Home Brewing Automation setup.