Data Sheet

Schematic Capture

As we can see, there are three logical blocks of circuitry; a reference generator for the ADC

module, an analog buffer for the pressure channel and a DC/DC converter to provide 5V from

the 3V battery to the other two sections on each pressure sampling time.

If you feel that you need more practice then you can use all of the techniques we have covered

so far to complete the schematic. Alternatively, if you are comfortable with the basics of

schematic entry we will load a pre-supplied completed schematic in the next section.

Regardless, there are a couple of points of note that are worth emphasizing.

Firstly, connectivity between sheets is achieved by having terminals with the same name on

both sheets. From the screenshot above you can see the named terminals and, switching to the

first sheet, the corresponding terminals with the same name. This technique allows signals to

propagate not only across a sheet but also across sheets.

Secondly, it is possible when placing wires to ‘guide’ the wire placement as you place the wire.

This is achieved by left clicking the mouse as you change direction, placing an ‘anchor’ to help

the follow-me algorithm place the wire the way you want. Typically, this is useful on more

complex wire trails but we can look at a simple example for the purposes of illustration.

Consider the connection between the negative input of U4:B and resistor R18 as shown here:

Negative input wire to R18

If we delete this wire (right click and select delete), we could replace the connection in the usual

way and the follow-me algorithm would make a decent job of it. However, if we wanted to be

more precise we could proceed as follows:

Hover the mouse over the negative input such that it turns green and then left click to

start wire placement.