Use this forum to chat about hardware specific topics for the ESP8266 (peripherals, memory, clocks, JTAG, programming)

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By foubarre
#19270 Hi.

I just plan to start a project with that chip and it looks very promising.
I still have informations missing or not clear enough for me. That is about the GPIO pins that are free for me to use.
I need a SPI and three to four outputs for my project to be viable.
looking at this page: wiki/doku.php?id=esp8266_gpio_pin_allocations
I will let GPIO0 and GPIO2 free for flashing operations.
it seems that i can use 12,13,14 for SPI, (no CS needed), then it gets problematic.

From that page, i read: "The CH_PD must be High, as well as the RST line and GPIO 2 (or left floating, i.e. unconnected)"
Can all of them be left floating or must only CH_PD be pulled up, or... something else?
And by the way, what pin is CH_PD?

At the moment, it seems that i can use GPIO1, GPIO3, GPIO4,GPIO5 and GPIO15 without interfering with the normal operations. Is that right?

Thank you.