Questions tagged [io-expander]

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ESP8266 soft resets when using a GPIO Expander

In my project I'm trying to use a PCF8574 to drive some peripherals, since the ESP8266 doesn't offer all the GPIO pins I need, however I seem to be having problems at the most basic level of driving ...
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  • 183
1 vote
0 answers
65 views

How to get a stable LED lighting without scintillation over I2C bus

I built an 8x8 led matrix using white 5mm LEDs. I drive the LEDs using the MCP23017 connected to an Arduino over the I2C bus. The wiring of the LEDs in the matrix is such that a row is made up of 8 ...
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  • 53
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2 answers
625 views

How to read input pin on MCP23017?

I'm working to develop a simple code for MCP23017 that I want to use to run LCD128x64. I was succeeded to set IODIRB as output and blink LED as a test. Now I want to read the pin state, but I couldn'...
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  • 283
1 vote
0 answers
121 views

Completing an action on button release help with delaying to give other modules time to repond

I'm currently having problems with my code it has several modules within the main one is my current keypad one working of a mcp23017. what I needed it to do is count how long a key is pressed and upon ...
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  • 11
1 vote
1 answer
356 views

Wire with MCP23008 I/O expander with I2C

I'm trying to read from an MCP23008 I/O expander using the Wire library over I2C. The MCP23008 is wired to address 0x04, giving an effective device address of 0x24. Writing to the device GPIO seems to ...
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  • 113
1 vote
2 answers
199 views

Arduino Uno - Building a Controller

I have the Arduino Uno and I'm working on a project to build a controller with different inputs and some outputs for readouts. In classic style, I got the Arduino Uno before realising that I might not ...
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1 vote
1 answer
1k views

Arduino Wire communication with MCP23008 GPIO pin expander to turn on an LED with a button press

I am using an Arduino Uno and an MCP23008 GPIO pin expander, I have a momentary button connected to GPIO 2 on the MCP23008 and an LED light connected to GPIO 1 on the MCP23008. What I want is for the ...
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0 votes
1 answer
302 views

MCP23S17 library crashes

I have a rather voluminous sketch with a heap of source and header files. Now I'm facing the problem, that controlling the MCP23S17 on my board fails in different ways within this sketch. This is ...
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