On-Board Power Supply; Medbg; Medbg Status Led - Atmel ATmega328PB Xplained Mini User Manual

To get 4 buttons the S touch area can be connected to e.g. PC2 by removing the 0Ω resistor R214 and
adding a wire or a 100k resistor from PC2 (D1) to the test point in B5.5.
.
2.4.

On-board Power Supply

The ATmega328PB Xplained Mini board has an on-board 3.3V regulator (150mA) which can be used to
power the ATmega328PB.
The J300 and J301 headers configure the ATmega328PB power supply and the board power source.
The default configuration is set by R300 and R301 0Ω resistors which can be easily removed to change
the default configuration.
Table 2-8 Board Power Options
Mode J301 connection,
target
5V (Default) pin2 connected to pin1 pin2 connected to pin1 Board and target powered by VBUS
3.3V USB pin2 connected to
pin3, remove R301
VIN pin2 connected to pin1 pin2 connected to pin3,
3.3V VIN pin2 connected to
pin3, remove R301
Tip: Use the BOD LEVEL fuse to avoid the following challenges:
For the CPU to successfully decode and execute instructions, the supplied voltage must always
stay above the minimum voltage level set by the chosen operating frequency.
When supplied voltage drops below this level, the CPU may start to execute some instructions
incorrectly. The result is unexpected activity on the internal data and control lines.
This activity may cause CPU Registers, I/O Registers and Data Memories to get corrupted.
To avoid these problems, the CPU should be prevented from executing code during periods of
insufficient supply voltage.
2.5.

mEDBG

The ATmega328PB Xplained Mini board has an embedded debugger/programmer enabling debugging
and programming of the ATmega328PB without any additional external equipment.
2.5.1.

mEDBG Status LED

The mEDBG has a green status LED connected to ATmega32U4 PC6 to signal the embedded debugger
state.
J300 connection, Function
board
pin2 connected to pin1 Target powered by 3.3V and USB
interface powered by VBUS
Board and target powered by VIN,
remove R300 J202.8. 1.8V < VIN < 5.5V
pin2 connected to pin3, Target powered by 3.3V. VIN as
remove R300 regulator input. 4V < VIN < 16V
Atmel ATmega328PB Xplained Mini [USER GUIDE]
Atmel-42469A-ATmega328PB-Xplained-Mini_User Guide-07/2015
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