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I'm attempting to connect a 16x2 LCD to my Pi 3 (Model B Rev 1.2), however it seems to short out the Pi when I connect the ribbon to the cobbler, causing the Pi to reset itself.

The LCD I'm using is a DEM16217 (Ver 01), I've checked the pins on the datasheet and I'm sure I have everything wired up correctly.

Here's what my breadboard looks like:

Fritzing breadboard layout

Wiring:

LCD              Pi
-------------------------------
LED+         -   5V
LED-         -   GND
VSS (Pin1)   -   GND
VDD (Pin2)   -   5V
V0  (Pin3)   -   GND
RS  (Pin4)   -   GPIO7  (Pin26)
R/W (Pin5)   -   GND
E   (Pin6)   -   GPIO8  (Pin24)
DB4 (Pin11)  -   GPIO26 (Pin37)
DB5 (Pin12)  -   GPIO5  (Pin29)
DB6 (Pin13)  -   GPIO6  (Pin31)
DB7 (Pin14)  -   GPIO13 (Pin33)

I'm left scratching my head at what I might have done wrong, any help as to why the circuit above is causing the Pi to short out?

Edit 1: Pics of the physical connections:

Breadboard physical connections

Pi to cobbler image

Edit 2 Working! LCD Working image

It appears I might have a dodgy breadboard! Thanks @SteveRobillard for the suggestion to check, as someone new to this I didn't think for a second it could be a new breadboard! Each time I connect the outer positive rails together to span the length of the breadboard it also connects to the Ground rail!! The pic in Edit 2 shows what I've changed to get it to work. I'll throw out this board and wire it up to another. Thank you for the help :)

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  • Can you include some pics of the connections. Also, double check that the ribbon cable is properly connected to the Pi and cobbler (the stripe on the ribbon cable goes towards the end of the board with the SD card slot). Sep 24 '17 at 21:43
  • @SteveRobillard I've uploaded a couple of pics of the connections, hopefully they're clear enough. I have the ribbon connected to a second cobbler and breadboard playing with some ADC chips earlier, and that works fine. It's only this breadboard with the LCD I seem to be having issues with. Does all the wiring look correct to you?
    – Leigh
    Sep 24 '17 at 21:55
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    I don't see anything immediately wrong, but If you have a meter you can doublecheck the voltage on the power pins (5v 3.3v and ground at the board to rule out a backwards cable. Sep 24 '17 at 22:19
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    You should answer your own question, separate from your question. There is even a badge for doing so. Sep 24 '17 at 22:54
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    Are you not getting the lightning icon appearing with 0.5A ? Recommended PSU is 5.1V 2.5A
    – CoderMike
    Sep 24 '17 at 22:56
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It turns out the breadboard I was using was faulty. Connecting the the live rails together to span the length of the breadboard (using orange jumper wires in my first pic), caused the live rail to connect with the ground rail.

Removing the live rail spanning jumper wire resolved the issue (see my updated image in Edit 2).

Thanks @Steve Robillard for the help! Much appreciated.

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