I'm pretty much out of digital pins on my uno...and this is probably a stupid question but never mind...
I know the norm is to use pins 10, 11 , 12 ,13 for spi, but i see that the board also has these pins on the header just above ARef. Can I use these pins instead (alongside the adafruit tft st7735 and spi libraries) to control my lcd and free up these pins for other uses. I should be able to gain enough to complete this project then hopefully. I'm literally about 2 pins short! I'm using the serial monitor so I cant use pins 0 + 1.
The Arduino UNO only has one hardware SPI port. It is connected to pins 10-13 and to the six pin ICSP header. If you don't need the speed of hardware SPI (up to 8 megabits per second) you can use some digital pins to implement software SPI but that won't gain you any pins.
Common ways to get more pins to use:
Switch some peripherals to I2C versions. They can share the two I2C pins among themselves.
Add some serial-in-parellel-out shift registers to get more digital output pins.
Add some parallel-in/serial-out shift registers to get more digital input pins.
Use a multiplexer to get more analog input pins.
Use an Arduino MEGA 2560 to get more of everything.
uobstudent:
I know the norm is to use pins 10, 11 , 12 ,13 for spi, but i see that the board also has these pins on the header just above ARef.
Your looking at the 3X2 pin connector? That's the connector to program the 16u2, so better not mess with it...
If all alse fails, go with an I2C port expander. Saved my projects many of times!