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Unformatted text preview: Name _________________________ ECET 20900 Spring 2011 Lab Exercise #13/14 LCD Multiple Displays Objective: This is a 2 week lab/test. The purpose is to for you to use a 2x24 character LCD to display four lines of text and data associated with four different variables using push buttons to scroll the display up and down OR a push button to toggle the scroll direction and a time delay of suitable length to produce a pause between each steps in the scrolling. The four variables are listed below along with their range of values. The order shown below is the order that the display will scroll and hence Flow Rate and Tank Level can never be displayed together: Flow Rate: over the range 20 to 250 GPM Temperature: over the range 50 to 200 deg F Tank Level: over the range 5 to 95 % pH Value: over the range 2 to 12 The system assumes that each of the above sensors are each connected to 4-20mA current loop that drives current through a 200 Ω burden resistor that produces a voltage in the range 0.8 to 4volts. Hence the raw ADC data must be scaled to the range shown above. So, for example, the 20 – 250 GPM range produces a 4 – 20mA current that produces a 0.8 to 4V signal across the burden resistor which generates raw ADC data (assuming 8 bit mode) over the range 40 to 204. This raw ADC data must be scaled to display flow bit mode) over the range 40 to 204....
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- Spring '08
- Pixel, Liquid crystal display, Display resolution, LCD, Push-button