As shown in the typical circuit, ADC can be interfaced with any microcontroller. You need a minimum of 11 pins to interface ADC, eight for data pins and 3 for control pins. As shown in the typical circuit the chip select pin can be made low if you are not using the microcontroller port for any other peripheral multiplexing. There is a universal rule to find out how to use an IC. All you need is the datasheet of the IC you are working with and take a look at the timing diagram of the IC which shows how to send the data, which signal to assert and at what time the signal should be made high or low etc. Note: Keep this in mind that whenever you are working with an IC and you want to know how to communicate with that IC, then simply look into the timing diagram of that IC from its datasheet.
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Unlike, pic microcontroller , Arduino and avr microcontroller , microcontroller do not have built in ADC. For example, you want to measure temperature with microcontroller and you are using LM35 temperature sensor to measure temperature.
LM35 temperature sensor gives output in the form of analog voltage. So we need to use analog to digital converter. We use Analogue to digital convertor ADC to convert the analogue signal into digital form. Analogue signal can be the output of some sensor. And then the data in digital format can then be used for further processing by the digital processors. Now in this tutorial we will learn about ADC and its interfacing using microcontroller.
It indicates the number of discrete values that an ADC can produce over the range of analog values. It is the voltage difference between one digital level and the next level that can be measured by ADC. In a 4-bit converter, an input of 1 Volt produce an output of , then the step size is 1 Volt. Distortion in the signal can be reduced by decreasing the step size to 0.
Ife we are using smaller step size, higher bit converter is needed to have maximum voltage. ADC is a single channel analog to digital convertor.
It takes only one analog signal. It has 8 bit resolution. Other ADC can have n bit resolution and n can be 8,10,12,16 or 24 bits. If ADC has higher resolution, it gives smaller step size. ADC stores the result in an internal register after conversion of analog data. This pin helps to get the data out of the ADC When the conversion is over, this pin goes low. Analog input connected to ground. Default reference voltage is 5V when not connected. Step size can be reduced by using this pin.
As we know that microcontroller willprovide control signals to the ADC. Its main connections are as follow:. Port 1 is used as input port and port 0 is used as output port. Potentiometer is used to adjust the voltage. If the analogue input voltage is 5V then all LEDs will glow indicating in binary which is the equivalent of in decimal. If the voltage is zero, no LED will glow.
When half voltage given:. Notify me of follow-up comments by email. Notify me of new posts by email. Send a low to high pulse to WR pin to start the conversion. Keep checking the INTR pin. Input voltage from the preset is varied and the output of ADC varies.
Interfacing Analog to Digital Converter-adc0804 with 8051(89c51,89c52) Microcontroller
Unlike, pic microcontroller , Arduino and avr microcontroller , microcontroller do not have built in ADC. For example, you want to measure temperature with microcontroller and you are using LM35 temperature sensor to measure temperature. LM35 temperature sensor gives output in the form of analog voltage. So we need to use analog to digital converter.
Interfacing ADC 0804 with 8051 Microcontroller
The data we process in a microcontroller normally deals with digital signals. But there may a situation where we have to deal with external inputs such as analog signals. All most all the input signals from physical sensors are of analog signals. In such cases, we can interface the microcontroller with an external device such as an ADC to convert the analog signal to a digital signal. Because our microcontrollers can only understand 0 and 1.
8051 – ADC0804 Interfacing
Adc Pin Out and Working. Apply 1. This is the reference voltage for ADC This is the voltage by which the step size of the ADC will be set to 10 mv. Lm35 Pin Out and temperature conversion formula. Port-3 pins 0, 1, 2 and 3 are used as cs chip select wr write rd read intr interrupt to control ADC Project code is given below and each statement well explained.