I've been messing with raspberry pi, and I am learning about interfacing it with analog devices. I am using the MCP3008 for that and following this tutorial here. I wired it up like the pictures below:

I did all of the required things to set up spi devices such as:

1. enable spi in raspi-config
2. uncommented dtparam=spi=on in config.txt.
3. ls /dev/sp* says /dev/spidev0.0 and /dev/spidev0.1

Everything to me seems correct, but the output from a potentiometer is still 0 no matter what i do with it. can anyone spot the problem?