HardLabs

Mk2

jeffc·nrf52-watch-obsolete·kicad/watch-mk2/mk2/mk2.kicad_pcb

Mk2 PCB layout, top view — open source Nordic nRF board by jeffc

About the Mk2 PCB

Mk2 is an open source Nordic nRF PCB design by jeffc, published on GitHub. It is a 2-layer board measuring 23.5 × 37.5 mm, with 49 components from 36 distinct parts.

Its main chip is the 113990582, from the Nordic nRF family. Other key parts include the M41T62LC6F, TPS60151DRV, LM3671MF-2.8_NOPB, MCP73831-2-OT and BMA400. By type, the board carries 11 capacitors, 11 resistors, 8 ICs, 5 connectors, 3 transistors and 3 jumpers.

It belongs with the wearables, power & battery and iot & wireless designs in this gallery.

From the project

obsolete repository - see https://github.com/jeffc/nrf52-watch-firmware

This repo is, at present, a work-in-progress playground for designing and building a smartwatch based on the nrf52840 microcontroller from Nordic.

RayTac MDBT50Q nRF52840 Module Main brains. nRF52840 chipset chosen for BLE capability and low (<1uA) sleep current. This is the module used in the Sparkfun Breakout Sharp LS018B7DH02 1.8" Memory LCD with FLExLight Frontlight Always-on display. Chosen for size and small power consumption. The LS018B7DH02 isn't sold directly by Sharp, and no datasheet is currently available. Unknowns are currently Does the display require 3.3V or 5V power? Does…

Main components on the Mk2

113990582M41T62LC6FTPS60151DRVLM3671MF-2.8_NOPBMCP73831-2-OTBMA400TPD2S017MAX17262REWL+T

Mk2 bill of materials (BOM)

49 components, 36 distinct parts.

QtyPartRefs
1
113990582
MDBT50Q
IC1
1
M41T62LC6F
IC2
1
TPS60151DRV
U1
1
LM3671MF-2.8_NOPB
U2
1
MCP73831-2-OT
U3
1
BMA400
U4
1
TPD2S017
U5
1
MAX17262REWL+T
U6
3
Si1308EDL
Q1, Q3, Q4
1
32.768kHz
Y1
1
Conn_01x10_Female
J1
1
2305018-2
J2
1
Conn_01x02_Female
J3
1
503480-0400
J4
1
Conn_01x02_Female
J6
1
Battery_Cell
BT1
2
Jumper_NO_Small
JP1, JP2
1
Jumper_NC_Small
JP3
1
B5
SW1
1
B1
SW2
Show 16 more
QtyPartRefs
1
B3
SW4
2
D_Schottky_x2_KCom_AAK
D1, D2
1
2.2uH
L1
2
12pF
C1, C2
2
10uF
C3, C7
2
4.7uF
C4, C20
3
2.2uF
C5, C6, C8
1
560pF
C9
1
0.47uF
C10
1
shunt
R1
3
100k
R2, R13, R15
2
27
R3, R4
1
2k
R9
2
5.1k
R11, R12
1
100
R14
1
10
R16

Mk2 design files

The KiCad project lives in the jeffc/nrf52-watch-obsolete repository on GitHub; these links point at the commit this page was built from.

Mk2: common questions

What microcontroller does the Mk2 use?

The Mk2 is built around the 113990582, from the Nordic nRF family.

How big is the Mk2 PCB?

The Mk2 measures 23.5 × 37.5 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the Mk2?

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

Where can I download the Mk2 design files?

From the jeffc/nrf52-watch-obsolete repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.

Can I use the Mk2 design in my own project?

The repository has no license, so all rights stay with jeffc. Use it as a reference, and ask the author before reusing the design.

Can I test firmware for the Mk2 without the hardware?

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

More boards in nrf52-watch-obsolete

Similar boards