Vcc is essentially the same term as Vdd on the Board of Education, and GND corresponds to Vss. Vcc and GND are used for supplying power to the IC.
The notation for the ADC0831's inputs and outputs works as follows: Vin(+) is the analog input, and D0 is the serial output. Next, we’ll use this decimal equivalent to calculate and displays the We’ll also program the BASIC Stamp to display the decimal equivalent of the binary output.
The BASIC Stamp will be programmed to read and store the 8-serial-bits transmitted by the ADC0831. The difference is that the ADC0831 depends on a clock signal sent by the BASIC Stamp to time the sending of each serial output bit. We sent serial binary digits (bits) to the BASIC Stamp using one pushbutton and the bits were synchronized to a second pushbutton that was used to send a clock signal.
Synchronous and serial are terms we learned about in Chapter #2.A higher resolution converter, such as 12-bit, would break the same voltage range into 4096 levels because you can count from 0 to 4095 with 12 binary bits. This means that the ADC0831 can approximate the voltage it measures as one of 256 levels. You can count from 0 to 255 (decimal) using an 8-bit binary number. 8-bit is also the resolution of the A/D converter. 8-bit is the number of binary digits the ADC0831 uses to describe the analog voltage it samples.An A/D converter measures an analog voltage sample and returns a binary number that describes the sample.The black casing houses and protects an integrated circuit. Each chip is a black casing with eight pins. The Analog and Digital Parts Kit has three chips used in these experiments. An integrated circuit (IC) is a circuit with microscopic components implanted on the surface of a silicon wafer.Let's look at what each of these terms mean: The ADC0831 is an integrated circuit referred to as an 8-bit analog to digital converter (A/D converter) with synchronous serial output. The ADC0831 Integrated Circuit - An 8-bit Analog to Digital Converter The three resistors can be viewed as a single resistance whose value is:
Three resistors in series are shown below. Resistors in Series: A chain of resistors connected end to end. So, the voltage we measure might be 1.234 volts or 3.857564… volts, or 4.9999… volts, etc. We will use our DVM to sample voltages over a continuous range, from 0 to 5 volts. When a source of voltage varies over a continuous range, it is considered an analog voltage. The DVM will then be used to measure samples from the pot’s continuous range of voltage outputs.Ĭontinuous range: A minimum value, a maximum value, and everything in between. A pot will be wired to the Board of Education and adjusted to make analog output voltage. In this experiment, we will make a DVM using the BASIC Stamp together with the ADC0831 integrated circuit. It describes the analog information with binary numbers for devices that process binary information, such as the BASIC Stamp. The ADC0831 is a common integrated circuit that does this job. We'll use the potentiometer as we did in Chapter #1 to make a range of voltages that can vary continuously between 0 and 5 volts on the Board of Education.Īlthough information about analog voltage can be processed efficiently with binary devices, the voltage has to be sampled and described using binary numbers first.
As a “continuously variable value”, analog voltage varies within a continuous range. In Chapter #1, we used an LED circuit to display changes in analog voltage level applied to a circuit. Since our DVM processes its measurements in binary, we'll start with a binary display and then modify it to the more conventional and easy to read decimal display. Making sense out of each measurement would be time consuming. It would still be a "digital" voltmeter, but it would have binary display instead of a decimal display. The digits 0 through 9 and a decimal point are used to display the voltage measurements as decimal values. A common use for a DC DVM is testing the voltage (potential) between the two terminals on a battery.Ī digital voltmeter is so named because it displays its measurements with digits. In this experiment, we will build a DVM for measuring DC voltage in the 0 to 5 volt range. Chapter 3: Basic Analog to Digital Conversion Ĭhapter #3: Basic Analog to Digital ConversionĪ digital DC voltmeter (DC DVM) is a handy tool for measuring voltage between two contact points.