Output Devices. Group 1.

Week 9 group assignment Output Devices

Weeks assignments

This week assignment was to measure the power consumption of an output device.

Test 1: OLED display 0.96 inch 128x64

With OLED display we created circuit where multimeter was connected between 3.3 V VCC line and display VCC connector. We used Arduino_Hello_OLED code from Adrian Torres' FABXIAO page.

Picture1: Test 1 setup

As the result we got 4.1 mA, which gives OLED display power draw of 0,014 W.

Picture2: Test 1 result

Test 2: LCD display 4x20 with 3.3 V backlight on

We used same circuit as before, just changed OLED to LCD display and uploaded new code for LCD from Adrian Torres' Adrianino page.

Picture3: Test 2 setup

As the result we got 15.6 mA, which gives LCD display power draw of 0,05 W.

At first we thought that our code was incorrect because we did'nt see any text in display, but after consulting our local instructor we realised that we had used 3.3 voltage instead of 5 volts for the display.

Picture4: Test 2 result

Test 3: LCD display 4x20 with 5 V backlight on

As we corrected the circuitry we got the text in display.

Picture5: Test 3 setup

As the new result we got 57.9 mA, which gives LCD display power draw of 0,29 W.

Picture6: Test 3 result

In this test the LCD display backlight was used. In the picture below you can see the jumper for enabling the backlight.

Picture7: Test 3 LCD display backlight jumper in place

Test 4: LCD display 4x20 with 5 V backlight off

Next we removed the backlight jumper and measured current draw.

Same code and circuitry was used.

Picture8: Test 4 LCD display backlight jumper not in place

Picture9: Test 4 setup

As the result we got 7.3 mA, which gives LCD display power draw of 0,04 W.

Picture10: Test 4 result

Test 5: Overall power consumption with LCD display 4x20 with 5 V backlight on

With LCD display power draw was so high that we could use our local instructor's USB powermeter.

Picture11: Test 5 setup

As the result we got 100 mA, which gives LCD display power draw of 0,51 W.

Picture12: Test 5 result