COURSEWORK - Digital Volt Meter (DVM) Display


1. Lab 7 - Task 5 was to create the assembly code to make a Digital Volt Meter that displays the message and the correct voltage on the LCD. Once you managed to display the hex value for the conversion you were required to convert this to an actual voltage reading in decimal.

255 = 5volts 
therefore
1 bit = 5/255 = 19.6 mV.

The display should be accurate to +/- 2 mV

2. The LEDs should also display the rounded percentage of the full scale output. Since there are 8 LEDs each one represents 12.5%. However, since we want the rounded percentage the LED on the LSB should be illuminated if the voltage is above 6.25% (312mV) and the next LED should illuminated if the voltage is above 18.75% (937mV) etc.... 


3. Alter the brightness of the most significant illuminated LED to represent voltages between the ranges so that if the value is half way between the range then the LED should be 50% brightness. This can be achieved by using Pulse Width Modulation (PWM) ie. Turn the LED ON for 50% of the time and OFF for 50% of the time will.


4. The code should set the RS232 serial port to 19200 baud rate and output the voltage value so that it is displayed on hyperterminal. The display should be refreshed every 100ms


5. Create FLOWCHARTS for the above.