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Newbie level 3
Dec 6, 2005
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connect 16f877 to lcd

anybody can help me to draw a circuit with one pic 16f877 microcontroller, two shht11 sensor one 16*2 lcd display and some switches,two valves ... i need to measure the humidty and after that i need to controll the valve
help me to draw the diagram
the oprogramming i will do

how to connect pic16f877a


have a look at the PICDEM 2 Plus from Microchip.
It has teh connection for the F877 with LCD and switches and also a Pot. So just change a bit the circuit and it will work for you.
Here is the link to the web page, in the user guide you will find in it towords the end circuit.
**broken link removed**

If you found my answer useful, click on the button that says Helped me. ( NO points will be taken from you! )

Good luck.


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connect hd44780 16f877

The SHT11 temperature/humidity sensor requires PICs two general I/O pins: one is driving CLOCK to SHT11, the other one is bidirectional DATA (see SHT11_Interface.png) ..

As far as the LCD display is concerned, I suggest that you consider the HD44780 from HITACHI; an example with this LCD and a PIC can be found at:
**broken link removed**

To operate valves you will need single general I/O pin and a RLY driver, examples below ..


16f877 connect

Simply connect VDD(pins 10,32), VSS(pins 11,31) pins to supply voltage and ground respectively.
Crystal will be connected between osc1 and osc2 pins (pins 13,14) -with recommended bufs to the ground at each pin to improve oscillator stability.
To get use of POR circuit embeded in the chip, just connect MCLR (pin 1) to VDD via a recommended series resistance (about 5 ~10 Kohm)
LCD data port can be connectd to PORTD pins (RD0 to RD7)
LCD control pins (can be connected to any pins from PORTC or PORTB or PORTE). I recommend you to tie the R/W pin og the LCD to ground (Write only), just connect RS and E pins of the LCD to the PIC. Use the constant delay mechanism to write on the LCD and don't poll the status !!
Humdity sensor can be connected as an analog input to any pin PORTA or PORTE. You will need to configure the chip to take just this pin as analog input. Of course this is valid in case that your sensor circut output gives you an analog voltage corresponding to the humidity value. There are other techniques that may give you frequncy or even a digital serial value. !!

That's all
Good Luck

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