2 months, 1 week ago.

Problems to use MCP23S17

I use this program to drive MCP23S17. (Refer below code.) /media/uploads/aaaaaYukiaaaaa/main.cpp A purpose of this program is to output by MCP23S17. Not need to think about inputting. I only want to output. In the real, I use 4 MCPS17. So I use "for loop". Mbed is master, a slave is MCP23S17.

I could compile it. It had no errors. But It didn't work well... I checked signals on scl, mosi, miso(SPI signals). Correct logic comes to slave pins surely. But MCP23S17 pins won't try to output...

In addition, I checked register of MCP23S17 written on the datasheet. It is correct. I can't find the wrong points of my code.

Do you know why it doesn't work well? If you know, pls teach me!

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