LCD 4-bit initializations

[hexreader]

I respectfully suggest that forum members stick with the hardware that OP is using. OP has very poor understanding of hardware, as evidenced by many wasted posts on several forums.

The development board information can be found on other forums - I can provide links if requested.

I recommend searching the other forums for more useful information. It may save a lot of wasted time repeating mistakes from the past

Keep it really, really simple for this poster

(my personal thoughts and opinions only - feel free to ignore)

 

[Djsarkar]

I have attached schematic but I am trying to find problem in the code still I am not getting expected data on my LCD

 

[paulfjujo]

hello,
with your schematic, we can't see how LCD is wired to the MCU...
Did you connect LSB of LCD data pins to Gnd ?

 

[betwixt]

Lots of errors in that schematic:

1. you MUST add decoupling capacitors across VSS and VDD.
2. diodes in line with CN1 are not needed and might stop it working.
3. no supply line to the 7-segment LEDS
4. Leave D0 - D3 of the LCD disconnected if you are using 4-bit mode. The LCD module has internal pull-up resistors.
5. if CN4 connects to the MCU, it needs series resistors in each LED.
6. nothing to indicate which connectors are wired to each pin of the MCU.

Brian.

 

[KlausST]

Hi

I respectfully suggest that forum members stick with the hardware that OP is using.

We asked several times for a schematic.
My post#20 was a response to your post#19. Just to mention that it's quit posible to use one port pin as input (switches) and output (display) at the same time / multiplexed.
I did not say that the OP should modify the wiring.

my personal thoughts and opinions only - feel free to ignore)

Yes. The OP already ignores several recommendations about 4bit and 8 bit ....but wonders why it does not work.

Klaus

 

[hexreader]

1. you MUST add decoupling capacitors across VSS and VDD.
2. diodes in line with CN1 are not needed and might stop it working.
3. no supply line to the 7-segment LEDS
4. Leave D0 - D3 of the LCD disconnected if you are using 4-bit mode. The LCD module has internal pull-up resistors.
5. if CN4 connects to the MCU, it needs series resistors in each LED.
6. nothing to indicate which connectors are wired to each pin of the MCU.

1. I had not spotted that - nice catch - surprised anything works
2. do you mean CN11?
3. PIC supplies current - no supply line needed - admittedly 1 Ohm resistors seem way too low in value for my thinking.
4. Agreed
5. The board DOES have LED resistors, but the schematic is faulty - discussed post #74 onwards here: https://forum.allaboutcircuits.com/threads/pic-development-board-with-pk3.172494/page-4
6. Yes schematic really sucks - but port connectors are connected 1 to 1 with MCU. Connections can be surmised using PIC pinout diagram

OP already had LCD working long ago: https://www.electro-tech-online.com/threads/how-to-initialize-lcd-16x2.159986/page-4#post-1387907

 

[Djsarkar]

Lots of errors in that schematic:
4. Leave D0 - D3 of the LCD disconnected if you are using 4-bit mode. The LCD module has internal pull-up resistors.
Brian.

We asked several times for a schematic.
Yes. The OP already ignores several recommendations about 4bit and 8 bit ....but wonders why it does not work.
Klaus

OP already had LCD working long ago: https://www.electro-tech-online.com/threads/how-to-initialize-lcd-16x2.159986/page-4#post-1387907

Thanks' to all of you for your help. I am connecting LCD directly with microcontroller. I have not used board LCD block for connection because data was not showing on LCD if I use board LCD block. In my post #10 I have attached screenshot that show data on screen but not as I expected. In Post #18 I have shown connection

From post #10 screenshot, its verified that hardware is correct, only the problem with program.

I have written program as per my understanding and I am trying to fix program