122-28176 Parallax Inc, 122-28176 Datasheet - Page 197

• Manufacturer Part Number: 122-28176
• Description: GUIDE STUDENT PROCESS CONTROL
• Manufacturer: Parallax Inc

Specifications of 122-28176

• Accessory Type: Manual
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: Propeller Education (PE) Kit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant

Where m is the slope of the line, and b is the y-intercept (where the line crosses the Y-
axis), which is 0 in this case.
The slope, m, is the change in y for a given change in x. m = ∆y/∆x. In Figure 6-4 the
denoted ∆y is around 50 for a given ∆x of 1 V, for a slope of 50/1 V. While we are only
approximating the changes from the graph, any two points on the linear line will yield the
same slope. It's best to choose two known values. We know that a voltage of 0 V in will
result in a binary value of 0, and a voltage of 5 V in will result in a binary value of 255.
Given these two points:
This provides a general equation of:
Testing the input value of 2 V:
Another way of stating the general line equation is as a transfer function for our specific
system:
∆y is ∆Output since that is how much the ADC binary value will change for a given ∆x,
or change in input to the ADC.
Since there are only 255 possible steps between 00000000 and 11111111, the ADC is
limited to how finely it can resolve a voltage. What would be the bit value for voltages
of 1.05 V and 1.06 V? 53.55 and 54.06. But since only integer values can be used, they
would both have byte counts of 54, rounding to the nearest integer.
temperature, this change between 105 °F and 106 °F would not be measurable.
When the BASIC Stamp processes the binary value, the process is reversed where the
byte value is converted into a temperature using code. In performing the conversion, a
m = ∆y/∆x = (255−0)/(5 V−0 V) = 51/V
y = (51/V)x
y = (51/V)2V + 0 = 102
Binary Value = (∆Output/∆Input)Input
Binary Value = (∆Binary Value/∆Vin)Vin
Binary Value = (51/V)Vin
In terms of