GPIO coding CC2530

Setting PxSEL = 0 (=use I/O pin for GPIO, manually controlled instead of peripheral device) and PxDIR = 1 (=I/O pin direction is output) for every I/O pin and then set Px = 0 to set pins as output low (where x = port number, 0,1 or 2) is the correct way, yes.

Since you set P1SEL &= ~0x0F, it indicates that you want to leave the pins P1.0, P1.2, P1.3, P1.4 unchanged. I assume these are already configured to be controlled by the USART1 peripheral, for use as UART or SPI interface.

It seems that you have a typo in your code, all the three last lines refers to P0, instead of P1 and P2. Maybe you've fixed it already.

The current consumption you can measure will not only depend on the state of your I/O pins and what they are connected to (even though it's important too), but also the amount of peripherals inside the system-on-chip is in use (e.g. timers, adc, usarts, dma etc), which power mode the CPU is in (if it's running or not), if the high-speed crystal oscillator (32 MHz XOSC) is enabled or not, if you are running the chip with a debugger attached (will increase power consumption in PM2/PM3) etc.

When you measured 105 µA -- which power mode was the chip in?

To get a low power consumption, it is important that I/O defined as outputs do not have heavy loads on them and no I/Os are left floating. The latter will happen to unconnected I/O pins unless they are configured as pull-up, pull-down or output.

The P1_0 and P1_1 pins do not have pull-up or pull-down functionality and should therefore be set as outputs if they are not connected, such as on the SOC_BB board. Also on the EB, these pins could float (I am not sure what the input characteristics of the circuit that they are connected to is). They should thus be configured as outputs. On the SOC_BB, the LED must be disconnected (or at least the output must be high so that the LED is off). On the EB there is a lot of load on all the pins, and thus it is difficult to control the power consumption.