This thread is a continuation of my previous thread, except this one is primarily focusing on the contruction of an amp hour meter and programming it, rather than the gathering of parts for it. (since the parts have just arrived, very slow mail order) I am getting very confused when looking at the circuit diagram (provided by faust9), I dont really know what is going on here, I am just going off faith that it will work. For the purposes of my questions, I will divide up the diagram in to 3 sections, Section 1 (from the far left side to R5) -W4, and W5 are "connectors of some sort, earlier given as bannana plugs. this is where my circuit that I wish to measure is connected up correct, accorss the . 1 ohm ressitor? that would put the amp hour meter in parallel with my circuit, so far so good if I am understanding. Section 2 (from R5 to where R3 reconnects to PB3) -The triangle shaped symbol with all the numbers is the Op Amp Right?, Which is really shaped like a recangular chip with no sort of numbers on it coresponding to the diagram, luck me. -Pointing up and down from the Op Amp, from #7 and #4 are arrowsm one is +5 v, which I assume I need to connect to my seperate input powersupply to supply it with 5 volts, but what about the other arrow, does that goto a ground? -by R7, which is an optional ressitor which I was going to leave out, there is an arrow pointing in both directions, with a -5v, so I assume that this needs to be connected with the -5 volts from my power supply, what is the arrow pointing in the other direction? what do I do if I choose to leave out R7, or even if I keep it in, how is it connected? Section 3 (from where R3 reconnects to PB3 to the right side of the page). -I am still unlear on why the "I" (labeled SW) symbol is needed or what exactly I am looking to put in there. I know it is a Push Button Normally open switch, but why is it neede, what does it do? and the arrow comming out to its left, is that ground? -Then there are several more +5v leads that I need to connect to my input 5 volt power supply. -Down at the bottom, on the ship, #4, there is a ground arrow, but I dont even know where I will connect this to a ground, the only ground I ever use is a screw in a plate of a light switch cover on the wall. but I dont think this is what you were meaning. -Then there are the W s, which are for in circuit programming I think. What if I decide I dont want to do any of that, I will just program it correctly out of circuit, then once I get it right, solder it in then and only then. couldnt I leave those out then? -Then it connects to the LCD screen, I am sure I'll have problems when I get to that stage. I am getting really confuses since I dont know what I am doing here, help if very much appreciated.