HardLabs

Millennium

kmatzen·millennium·pcb/phonev6.kicad_pcb

Millennium PCB layout, top view — open source AVR/Arduino board by kmatzen

About the Millennium PCB

Millennium is an open source AVR/Arduino PCB design by kmatzen, published on GitHub under the MIT license. It is a 4-layer board measuring 81 × 114 mm, with 64 components from 36 distinct parts.

Its main chip is the Arduino_Micro_Socket, from the AVR/Arduino family. Other key parts include the TDA2822M, Arduino_Micro_Socket (display) and ADA3708. By type, the board carries 20 capacitors, 15 resistors, 10 diodes, 7 connectors, 5 test points and 3 modules.

It belongs with the audio and power & battery designs in this gallery.

From the project

I took an old pay phone from the 2000's and replaced the brains with a raspberry pi and some arduinos.

This directory contains the PCB design files created with KiCad.

- phonev2 (removed): Dual LM358 op-amps, raw power connector, pin headers for audio. - phonev4 (earlier fabrication): Single LM386 power amplifier for ringer only, XL6009 boost converter, RJ9 and 3.5mm jacks. Had two design flaws: speaker output coupling (#42) and unamplified handset earpiece (#44). - phonev5 (previous schematic): TDA2822M dual-channel amplifier replacing the LM386, fixing both audio design flaws. Adds reverse polarity protection, ESD protection, power LED, fuse, test points, and improved I2C pull-ups. -…

Main components on the Millennium

TDA2822MArduino_Micro_SocketArduino_Micro_Socket (display)ADA3708

Millennium bill of materials (BOM)

64 components, 36 distinct parts.

QtyPartRefs
1
~
U1
1
TDA2822M
U2
1
Arduino_Micro_Socket
A1
1
Arduino_Micro_Socket (display)
A2
1
ADA3708
A3
1
AO3401A
Q1
1
coin
J1
1
keypad
J2
1
display
J3
1
RJ9
J4
1
WQP-WQP419GR
mic
Wenzhou QingPu Electronics Co
J5
1
card_reader
J6
1
WQP-WQP419GR
speaker
Wenzhou QingPu Electronics Co
J7
1
2A
F1
1
5V_MAIN
TP1
1
Pi 3.3v out
TP2
1
Ground
TP3
1
SDA
TP4
1
SCL
TP5
1
Red LED
D4
Show 16 more
QtyPartRefs
3
P6KE6.8CA
D5, D6, D7
2
Green LED
D8, D9
2
Yellow LED
D10, D11
2
Blue LED
D12, D13
9
0.1u
C1, C2, C3, C4, C5, C16, C18, C19 +1
3
100nF
C6, C9, C10
3
100µF 16V
C7, C11, C12
1
4.7µF
C8
4
22u
C13, C14, C15, C17
2
4.7k
R1, R2
1
1kΩ
R3
6
1k
R4, R5, R12, R13, R14, R15
2
10k
R6, R7
2
4.7
R8, R9
1
330
R10
1
3.3k
R11

Millennium design files

The KiCad project lives in the kmatzen/millennium repository on GitHub; these links point at the commit this page was built from.

Millennium: common questions

What microcontroller does the Millennium use?

The Millennium is built around the Arduino_Micro_Socket, from the AVR/Arduino family.

How big is the Millennium PCB?

The Millennium measures 81 × 114 mm, has 4 copper layers and is 1.6 mm thick.

How many components are on the Millennium?

64 components, from 36 distinct parts. The full bill of materials is listed on this page.

Where can I download the Millennium design files?

From the kmatzen/millennium repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.

Can I use the Millennium design in my own project?

Yes, under the terms of its MIT license, which kmatzen chose for the repository.

Can I test firmware for the Millennium without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug AVR/Arduino firmware against it before you order a PCB.

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