Questions tagged [mcp23s17]

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How can I multiplex LEDs using PIC16F1768 mcu and MCP23S17

22 LEDs will use in a project as a display, where 11 will use to show the brightness and rest will use for color. For thar MCP23S17 I/O expander is used along with PIC16F1768(QFN) microcontroller. MCU ...
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50 views

MCP23017 INT Pin always high - INT cannot be cleared

trying to enable INT on MCP23017 so that, in case of a state change on any PIN from Port A (e.g from low to high) an interrupt should be triggered on INTA. Unfortunately the INTA pin remains high as ...
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77 views

Pressing one key in a button matrix reads all keys in that column

I'm using an MCP23017 IO Expander to make a button matrix (4x4). ...
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43 views

MCP23S17 - do I have to use both Chip Select and Hardware Addressing?

I've used MCP23S17 before. 6 of it and I just used Chip Select. Hardware address pins all 0. https://ww1.microchip.com/downloads/en/DeviceDoc/20001952C.pdf In datasheet, hardware addressing can be ...
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139 views

Why is the MCP23S17 device getting too much hot suddenly and randomly Raspb 4A?

Circuit is a Raspberry Pi 4A SPI master node talking with one MCP23S17 device: datasheet. I'm testing the singlest circuit version in a protoboard. We are using A bank GPIOs for reading, and B bank ...
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31 views

Connecting loads to an MCP23S17 GPIO outputs

I would like to connect various MCP23S17 datasheet devices to the Raspberry Pi3 MB SPI port. But first I would like to start making some test with a single connection: only one chip. After this I will ...
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1answer
104 views

What about MCP23S17 GPIO pins output ports being also used to be read by input pins?

We are connecting Raspberry Pi3B with some MCP23S17 expanders: MCP23S17. I have read that they could emulate an open-drain outputs, playing with high Z state of the pin when configured as input. ...
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61 views

Does a Mcp23s17 output pin keep the value after being unselected?

I'm designing a SPI based communiations circuit between Raspberry Pi4+B as a master and (n x 8) GPIO expander modules, as slaves. Concretely we have selected an MCP23S17 GPIO expander: Datasheet By ...
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566 views

NODEMCU _ MCP23017 IO Port Expander Schematic Design

I am designing a relay driver using NodeMCU and need additional IO Ports, therefore I have designed a schematic utilizing MCP23017. I think the schematic looks good, however before I order PCB's based ...
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211 views

MCP23S17 IOCON register values do not update correctly

I am currently testing the functionality of a Microchip MCP23S17 SPI 16-bit GPIO port expander for an application with a number of external inputs & outputs. The initial configuration of an ...