No the pins are unlikely to be exposed on any of the other sockets. You will need to use the I/A port and split it. As Andre says, I2C and Analog In are very specific pins, whereas X sockets are usually just GPIOs that can be substituted among many other sockets. You could try software I2c but I don’t know how effective it’ll be for you
The simple answer here is that the modules in question use many pins and it’ll be a little complex. It will also require you to approach two aspects - the electrics/wiring, and then modifying the drivers.
I realise you’re new here, so I wanted to say, if this is starting to freak you out let us know
From the Seeed hardware files in the Gadgeteer source, I have checked the pin usage of each module.
Barometer (I socket) uses pins 1, 3, 8, 9, and 10.
Moisture (A socket) uses pins 1, 3, 5, 6, and 10.
Barometer therefore uses 3v3, !GPIO, SDA and SCL, and GND
Moisture uses 3v3, AIN(!G), AIN, GPIO and GND.
So to start with, the pin 3 will potentially be hard to unravel. You would need to leave moisture on pin 3 in case it’s using it for Analog In; I’ve checked the code for the Barometer and it is NOT using this as an interrupt pin so we can find another non-conflict GPIO pin for that, woo hoo.
Pin 5 is an Analog In pin as well; there’s no conflict here so you should be ok here.
Pin 6 is a GPIO so it could be moved to anywhere if needed, but it currently doesn’t conflict so again it’s ok to stay where it is.
Pin 8 and 9 are the I2C pins so you can leave them where they are.
Pin 10 is GND - whatever you do make sure these pins are connected on both modules.
So here’s the plan.
Take a breakout module. Plug it into the Socket A/I. This is "Breakout1"
Take two more breakout modules, plug each one into a module.
Connect pins 1, 2, and 10 on all three breakouts together. This gives you power and ground sorted.
On the Barometer’s breakout, connect the following:
Pin 8 --> Breakout1-8 (ie pin 8 on breakout1)
Pin 9 --> Breakout1-9
Pin 3 --> Breakout1-4
On the Moisture probe’s breakout, connect the following:
Pin 3 --> Breakout1-3
Pin 5 --> Breakout1-5
Pin 6 --> Breakout1-6
Then, you have to get the drivers sorted ! This is where I’m going to point you to the reference https://www.ghielectronics.com/docs/122/gadgeteer-driver-modification
At a minimum, you need to include the two drivers for these two modules, and you’ll need to share a socket so you can’t reserve the socket in both drivers, and you need to change the Barometer module’s pin definition to reflect that we’re using pin4:
this.XCLR = new GTI.DigitalOutput(socket, Socket.Pin.Three, false, this);
this.XCLR = new GTI.DigitalOutput(socket, Socket.Pin.Four, false, this);
Good luck !
(oh PS: you could always look at a second mainboard that has these on two different sockets, especially if that freaked you out and Welcome to the forum !!! )