Imported from GitHub: timdrysdale/atmega-demo · commit 0c91b8d · license GPL-3.0

Description

PCB to demonstrate atmega microcontroller

README

atmega-demo

PCB to demonstrate atmega microcontroller together with ACS712 and temperature sensor.

Purpose

This board will be used to monitor power consumption and temperature in remote lab boxes.

Schematic

The key components are an Atmega328P, a CH340 USB transceiver, an ACS712 current sensor and a simple analog temperature sensor. DTR reset is enabled to support re-programming over USB, while ICSP header is supplied for initial programming. Both CH340 and Atmega are using 12MHz crystals, which yields 0.1% baud rate error at 57600 baud for the Atmega.

BOM

Comment	Designator	Footprint	LCSC
0.1n	C1	Capacitor_SMD:C_0603_1608Metric	C100040
100n	C8,C11,C12	Capacitor_SMD:C_0603_1608Metric	C14663
0.1u	C2,C3	Capacitor_SMD:C_0603_1608Metric	C14663
100n	C4	Capacitor_SMD:C_0805_2012Metric	C49678
22p	C5,C6	Capacitor_SMD:C_0603_1608Metric	C1653
4n7	C7	Capacitor_SMD:C_0603_1608Metric	C53987
33p	C9,C10	Capacitor_SMD:C_0603_1608Metric	C1663
Green	D1	LED_SMD:LED_0603_1608Metric	C72043
Blue	D2	LED_SMD:LED_0603_1608Metric	C72043
PRTR5V0U2X	D3	Package_TO_SOT_SMD:SOT-143	C2827688
Conn_01x04_Male	J1	Connector_PinSocket_2.54mm:PinSocket_1x04_P2.54mm_Vertical
AVR_ICSP	J2	Connector_PinHeader_2.54mm:PinHeader_2x03_P2.54mm_Vertical
USB_B_Micro	J3	Connector_USB:USB_Micro-B_Amphenol_10118194_Horizontal	C132563
Screw_Terminal_01x02	J4	TerminalBlock:TerminalBlock_bornier-2_P5.08mm
10u	L1	Inductor_SMD:L_0805_2012Metric	C1046
10K	R1	Resistor_SMD:R_0603_1608Metric	C25804
68	R2,R3	Resistor_SMD:R_0603_1608Metric	C27592
1M	R4	Resistor_SMD:R_0603_1608Metric	C22935
NO	SW1	Button_Switch_SMD:SW_SPST_PTS810	C116501
TestPoint	TP1,TP2,TP3,TP4,TP5	TestPoint:TestPoint_Keystone_5015_Micro-Minature	C238130
ACS712xLCTR-20A	U1	Package_SO:SOIC-8_3.9x4.9mm_P1.27mm	C10681
MCP9700T-HTT	U2	Package_TO_SOT_SMD:SOT-23	C150830
ATmega328P-AU	U3	Package_QFP:TQFP-32_7x7mm_P0.8mm	C14877
CH340G	U4	Package_SO:SOIC-16_3.9x9.9mm_P1.27mm	C14267
12MHz	Y1,Y2	Crystal:Crystal_SMD_3225-4Pin_3.2x2.5mm	C97242

Production

DFM

The design for manufacture showed a couple of small issues:

The parts placement as shown on upload (known to disply with incorrect rotations):

The corrected placement after processing by JLCPCB (parts now oriented the same as the 3D output from KiCAD: