ESP8266 Community Forum

- Tue Nov 07, 2017 2:04 pm #71615 I am doing a project that would require more digital pins than my esp8266 12e has. I have used a mcp3008 and made more analog pins but now I need a couple more digital pins. Can someone point me in the direction how I go about doing this. I have a total of 8 relays I have to control. Thanks for the help

Ray

- Tue Nov 07, 2017 11:51 pm #71625 You can use a Port Expander.

8 bit one:
- PCF8574 - GPIO output example
- PCF8574 - GPIO input example, 4x4 keyboard interface

16 bit one: PCF8575 – Remote 16-bit I/O expander for ESP8266 – I2C-bus

PWM 16 channels:
- PCA9685-16Channel 12-bit PWM I²C-bus LED controller Driver
- PCA9685 Web interface and Driver example

Happy breadboarding,
TJ.

ESP8266 MPDMv4 AC MAINS Dimmer Home: http://esp8266-projects.com/2016/04/mpdmv4-mains-dimmerswitch-html/
Available on Tindie: https://www.tindie.com/products/nEXT_EVO1/universal-ac-mains-dimmer-mpdmv41/

- Wed Nov 08, 2017 5:04 am #71636 Since you only need outputs, you can also use shift registers. Using 3 I/O you can get any number of outputs (8 per register & you can daisy chain as many as needed).
They are also dirt cheap and easy to use, just google for 74hc595 and you'll find plenty of examples.

- Wed Nov 08, 2017 6:10 am #71637 Or, since:
a) You're already using SPI for the ADC.
b) There are apparently libraries for it

Why not look at the MCP23S17 ?