Using shift register for serial input

Using Arduino Sensors
1

Hi, I'm trying to use the 74HC595 shift register to get serial input from 2+ sensors and control mosfet. The board I'm using (similar to esp8266-01) only has rx/tx and 1 another gpio pin. So far I got the shift register to control leds using these pins but I'm wondering how I would wire/code it to get data from multiple serial inputs (I'm using ultrasonic sensor with rx & tx data out pins)?

Thanks.

2

Hi @Charlieglider .
Do you want to convert parallel inputs to serial using the 74HC595?

Generally speaking the 74HC595 is used to do the reverse, transforming a serial pulse train in parallel.

Could you please post the schematic you are using.

And if you haven't, how about reading the topic:
How to get the best out of this forum

And post a lot of information to help us help you.

As Pharaoh TutanKamon said in 1340 BC (good help starts with good information).

RV mineirin

3

74HC595 is serial in, parallel out only. For parallel in, serial out use the 74HC165.

To add bi-directional GPIO pins the I2C expanders MCP23008 (8 bit) and MCP23017 (16 bit) or their SPI cousins MCP23S08 and MCP23S17.

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Hi I currently don't have a schematic as I'm still deciding which shift register to use and how to connect them. But I suppose I will need to use something like an 74HC165 or I2C expander to take in sensor inputs. What do you think the best way to this is is so I can also control my mosfet?

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I see, so I can use the 74HC165 to expand the sensor inputs. How would I be able to expand the 3 pins I have to also do serial in parallel out to control the LEDS as well? Would the I2C expanders you mentioned be able to this, and how would I connect them? Thanks

7

IIRC, Adafruit has a library to control this chip. Don't forget the decoupling cap!

1 Like
8

How would I connect this if it uses analog pins?

9

What is "this"? Is it an analog signal?

Analog pins (except A6 and A7 on Nano) are digital pins with analog input as a special function. You can do anything with an analog pin that you can do with any digital pin.

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can this do serial inputs too (view sensor data)?

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You can view the changes from 0 to 1 on your serial monitor. You cannot view "data" because you have NO clock timing to tell one 0 from the next or one 1 from the next.
Paul

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