![pic16f676 adc with pbp3 pic16f676 adc with pbp3](http://www.next.gr/uploads/40/ADC-Block-Diagram-outlined-removed.png)
The capacitor 0.1uf makes the adc input a bit stable because 10bit adc is really sensitive. You can also increase or decrease the range by changing resistor network and the calculations a little bit. Now with the voltage divider the maximum voltage is 30v so the calculations will be 30/1023=0.02932 volts/count Means if the adc count is 188 then input voltage is 188 * 0.0048878 = 0.918 volts And to keep as less as possible attenuation on the under test voltage we have to keep the voltage divider resistor value in few thousand ohms because it takes very little current from the target but as much to drive adc of pic.ġ0bit adc resolution we get 1023 maximum count So we need is Vin/6 => 30/6 =5v voltage divider. So what we have to do is make such voltage divider that can divide out maximum range 30 volts to 5 volts. We all know very well that by default pic micro controller ADC reference voltage is set to vcc(+5v in this case). In my circuit the refresh rate is about 50hz.Īs you can seen in the schematic the 47k resistor and 10 k trim pot is connected ias a voltage divider configuration. You can find more about driving multiplexed 7 segment led display from a pic mcu in application note from microchip AN557 Four Channel Digital Voltmeter with Display and Keyboard. It means we switch on one display and put the corresponding digit on this while other two displays are off this cycle goes for each of the displays. As you can see in the schematic the displays are multiplexed with each other. Then 3 digits of comm anode 7 segment display is used to display final converted voltage. The internal adc of the mcu with a resistor network voltage divider is used to measure the input voltage. PIC16F676 is the heart and brain of this circuit. The possible applications are on bench power supply or as a digital panel meter in various systems. You can use this circuit to measure up to 30V DC.
![pic16f676 adc with pbp3 pic16f676 adc with pbp3](https://slidetodoc.com/presentation_image/9c1468345b065d291022a36ef51a589e/image-32.jpg)
This is a simple 30V volt meter using PIC16F676 micro controller with 10-bit ADC (analog to digital converter) and three 7 segment LED displays.