output and input in one shiftregister

Other Hardware LEDs and Multiplexing
1

hi,

I have working in esp8266 and I have 2 pins for 3 swithes(one of them for intrrupt!) and 4 reles

I want using 74hc595 shift register and I dont know how !?!?!

pls help me with interduction source or a example..

thank you!!!

2

One way (there are others) shiftOut

3

thank you so much !!

but I said I have two pin and i have 3 swithes(input)and one of the is untrrupt key and 4 rele device(out put )
can I use one shift register for them ?!

becouse I didn't saw a example or article for this problem!

4

Which shift register have you got ?

It is not clear what you want to do with the switches, interrupt and relays. More detail please.

5

my shiftregister is 74hc595

I am working with esp8266 and I have 2 pins useless!

and I have 3 keys for control of the esp8266 and 4 rele for control devices

so I need 3 pinss for input and 4 pins for output!! But I have just 2 pins in esp8266

6

The 74hc595 cannot be used to read the state of inputs and pass them on to the ESP. It is a strictly output device

Search for port expander instead

7

thank you so much!

Now can I use other shift register for input and output at the same time ?!!

8

Now can I use other shift register for input and output at the same time ?!!

What other shift register ?

Did you search (this forum to start with) for port extender ?

9

Check out the PCF8574. It use I2C, have 8 ports and each port can be set to either input or output.

10

Probably the best for you is to use two chips, a parallel load serial output and your 595's. Using the SPI you can concurrently send 8 output bits and read 8 input bits (MOSI, MISO). You might want to get the ESP8266 cookbook and read it. You will find several variations of it. Also on line there are many videos etc showing the ESP8266 and how to do what you want. This additional information will go a long way in getting your problem solved. Once you get past this you then need to select your sensors and actuators. At that point you start on the hardware design and write your software.

11

christ76:
thank you so much!

Now can I use other shift register for input and output at the same time ?!!

The 74HC299 does both serial->parallel and parallel->serial, however it can't do both at the same time.
(think about it - loading a register in parallel overwrites all 8 bits).

It could be used for input work alongside a 74HC595 used for outputs, as a homebrew port-expander setup.

Port expanders can be more flexible.