I'm very new to electronics engineering, so please forgive me if I'm asking stupid questions!
I'm working on a device which is based around an Atmel Sam L21 ARM MCU with 4 UART devices attached (amongst other things), and powered by a couple of AA batteries. I've attached a very crude diagram of how things are connected, but I have the following questions:
- Which pins are used to power the MCU? I assume it's either VDDCORE or VDDIN and a GND pin at the top.
- Do I need to add decoupling capacitors between the power supply and the MCU?
- Are the peripheral devices powered directly from the batteries, or through the VDDIO pins on the MCU?
- Again, do these need decoupling capacitors between the peripherals and the MCU?
I've read a couple of really detailed posts on here that relate to how and when to use decoupling capacitors, and I'm planning on reading through them again today to get my head around it all, but if someone could help me out with this power supply stuff, I'd be hugely appreciative!