No Backlight Even with 12V

The LCD and Keypad Shield gives you a handy 16-character by 2-line display, 5 buttons and a controllable backlight.
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christo
Posts: 4
Joined: Wed May 01, 2013 4:52 am

No Backlight Even with 12V

Post by christo » Sun May 05, 2013 11:42 pm

Using a Freetronics Eleven and the LCD & Keypad Shield, got example code working fine for displaying messages, custom characters, scrolling etc.

But I can't get the backlight to illuminate.

I have read about the voltage needs of the backlight on the LCD & Keypad Shield from the relevant quickstart guide here: http://www.freetronics.com/pages/16x2-l ... YWhIyv8_Zc

So I didn't expect the backlight to work on USB power, even though there are several videos showing it working, for example the Jaycar youtube example here: http://youtu.be/hZko4IxjAQ8?t=2m48s

The quickstart guide suggests running on 7v-9v through the power socket on the Freetronics Eleven. I attached a power source and have tried the following power sources both in addition to the USB and instead of the USB power, all with the same failure to light the backlight: 6v, 7.5v, 9v, 12v. Again in each case the text messages show up, just not with a backlight.

I'm using pin D3 as per the instructions and I have not attempted any of the reassignment surgery documented on the freetronics site.

It seems the backlight is broken.

Any tips/advice?

christo
Posts: 4
Joined: Wed May 01, 2013 4:52 am

Re: No Backlight Even with 12V

Post by christo » Mon May 06, 2013 12:47 am

Thanks I'll try that today.

christo
Posts: 4
Joined: Wed May 01, 2013 4:52 am

Re: No Backlight Even with 12V

Post by christo » Mon May 06, 2013 5:16 am

That was it.

A replacement shield worked fine straight away.

FYI I did notice on the faulty shield that the smd resistor at the very top right position (to the right of the contrast pads) was absent. It's present on the working replacement shield.

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