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Topic: new LiquidCrystal library problems (Read 4 times) previous topic - next topic

Docedison

Pin 8 of the 74HC595 has no ground it is connected to several other pins but not ground.

Doc
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fm

The schematics that are published in the library's wiki have been tested and are working with LCD library. They all have their corresponding bench mark. There are several schematics which I haven't published in the wiki for the SR2W and SR3W class but they are well documented in the header files.

Review the connections of to the board and make sure that the initialization of the library is correct by passing the correct pin assignement (data, clk, enable). How are you initializing the library? As you have it wired it should be: LiquidCrystal_SR iLCD(2, 3, 4);

On the published wiring, at first glance, the whole thing looks OK appart from the 74HC595 ground pin (which you have it floadting) looks alright.
   

Z.K.


Pin 8 of the 74HC595 has no ground it is connected to several other pins but not ground.

Doc


Ah, I missed that, thanks.  Pin 8 and 13 should have been grounded, they are now. Unfortunately, that did not help, still a blank display. 

Z.K.


The schematics that are published in the library's wiki have been tested and are working with LCD library. They all have their corresponding bench mark. There are several schematics which I haven't published in the wiki for the SR2W and SR3W class but they are well documented in the header files.

Review the connections of to the board and make sure that the initialization of the library is correct by passing the correct pin assignement (data, clk, enable). How are you initializing the library? As you have it wired it should be: LiquidCrystal_SR iLCD(2, 3, 4);

On the published wiring, at first glance, the whole thing looks OK appart from the 74HC595 ground pin (which you have it floadting) looks alright.


Ah, good point.  I had been messing around with the code so much, I forgot to check that the example sketch was using the correct pins.  So, after grounding pin 8, changing the pins to what they should be, and turning up the contrast, it works now.  Thanks a lot.

Z.K.

#24
Sep 08, 2012, 07:29 pm Last Edit: Sep 08, 2012, 07:34 pm by Z.K. Reason: 1
Thanks everyone for your help. The serial LCD with the 595 shift register is working now so I will mark this conversation as solved.

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