Dangerous Prototypes

Other projects => Past projects => USB serial LCD backpack => Topic started by: sormariano on September 14, 2013, 05:20:19 pm

Title: LCD backpack GND pin: where to connect ?
Post by: sormariano on September 14, 2013, 05:20:19 pm
Hello to everybody.
I just bought an LCD&USB serial backpack and I have problems in connecting it to a PC1602AR that is an HD44780 compatible device.
The PC1602 pinout has 14 pins  1st VSS (ground), 2nd VDD, 3rd VO and so on till the 14th D7
but if I connect it to the backpack, the fuse on the backpach overheats and nothing happens. If I do not connect the GND pin of backpack to the GND pin of the PC1602, the LCD goes on (even if I'm not still able to see anything on it, just black boxes).
Am I doing something wrong ?
Thank you
Title: Re: LCD backpack GND pin: where to connect ?
Post by: MickM on September 14, 2013, 11:36:53 pm
Hi sormariano;
  here is the data sheet for that display:
http://docs-europe.electrocomponents.co ... 0b97a0.pdf (http://docs-europe.electrocomponents.com/webdocs/00b9/0900766b800b97a0.pdf)

Are you sure that you have identified pin 1 correctly?
Page 13 shows the connector.
With the display facing up, and the connector on the left.
Pin 1 is lower inside.

If you have it backwards then you connect the backlight LED directly across the power lines.
With no resistor the fuse will blow.

The black boxes mean that the contrast pot needs to be adjusted.
Usually very near to one end of it's travel.


Hope that this helps.

Mick M
Title: Re: LCD backpack GND pin: where to connect ?
Post by: sormariano on September 15, 2013, 06:30:51 pm
It seems that I have no more the problem. Maybe it could be caused by some wrong soldering even if I well checked all them.
Thank you for your answer
By the way ok, the black boxes are due to contrast but now problems are not ended.
In Linux and lcdproc I am now in the problem that this user had here http://http://dangerousprototypes.com/forum/viewtopic.php?f=60&t=3992#p40031

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