HardLabs

Crommeter

ShawnHymel·crommeter·hardware/crommeter/crommeter.kicad_pcb

Crommeter PCB layout, top view — open source RP2040/RP2350 board by ShawnHymel

About the Crommeter PCB

Crommeter is an open source RP2040/RP2350 PCB design by ShawnHymel, published on GitHub. It is a 4-layer board measuring 83.2 × 125.8 mm, with 53 components from 20 distinct parts.

Its main chip is the RP2350 Stamp, from the RP2040/RP2350 family. Other key parts include the SDTC40R2W. By type, the board carries 31 resistors, 8 diodes, 4 connectors, 3 transistors, 2 ICs and 2 capacitors.

It belongs with the wearables designs in this gallery.

From the project

SHOW ME WHAT YOU GOT

Badge accessory (SAO) to measure general sound level from cheers and applause. Gives a (somewhat) precise measurement of sound pressure level in dB.

This was made in Rust for no other reason than to test my embedded Rust skills.

To build the project, you'll need Rust on your computer. Follow the instructions here to install Rust.

Next, install the Thumbv8m target processor:

Main components on the Crommeter

RP2350 StampSDTC40R2W

Crommeter bill of materials (BOM)

53 components, 20 distinct parts — part numbers from the project's BOM.

QtyPartRefs
1
RP2350 Stamp
RP2350_Stamp
Solder Party
U1
1
SDTC40R2W
Common Cathode
ChromeLED
U2
3
BSD840NH6327XTSA1
INFINEON
Q1, Q2, Q3
1
BHR-06-VUA
Badgelife_sao_connector_v169bis
Adam Tech
X1
1
10118194-0001LF
Amphenol
J1
1
10129380-903001BLF
Conn_01x03_Pin
Amphenol ICC (FCI)
J2
1
14417
PRT-14417
SparkFun Electronics
J3
1
S2B-PH-SM4-TB
JST
P1
1
ICS-43434
TDK InvenSense
MK1
1
FSM2JSMAATR
SW_Push_Dual
TE Connectivity ALCOSWITCH Switches
SW1
8
CUW Y3SH.B2-GFJD-5J6T-Z242-20-R18-Z
CUW_Y3SH.B2-GFJD-5J6T-Z242-20-R18-Z
OSRAM Opto Semiconductors Inc.
D1, D2, D3, D4, D5, D6, D7, D8
1
CC0603KRX7R7BB104
0.1uF
YAGEO
C1
1
CC0603KRX7R7BB105
1uF
YAGEO
C2
1
RC0603FR-0747KL
47k
YAGEO
R1
1
RC0603FR-0768RL
68
YAGEO
R2
8
RC0603JR-7W120RL
120
YAGEO
R3, R4, R5, R6, R7, R8, R9, R10
5
RC0603FR-7W100RL
100
YAGEO
R11, R13, R15, R21, R27
5
RC0603FR-07100KL
100k
YAGEO
R12, R14, R16, R22, R28
8
RC0603FR-1347RL
47
YAGEO
R17, R18, R19, R20, R23, R24, R25, R26
3
DNP
R29, R30, R31

Crommeter design files

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

Crommeter: common questions

What microcontroller does the Crommeter use?

The Crommeter is built around the RP2350 Stamp, from the RP2040/RP2350 family.

How big is the Crommeter PCB?

The Crommeter measures 83.2 × 125.8 mm, has 4 copper layers and is 1.6 mm thick.

How many components are on the Crommeter?

53 components, from 20 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.

Where can I download the Crommeter design files?

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

Can I use the Crommeter design in my own project?

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

Can I test firmware for the Crommeter without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug RP2040/RP2350 firmware against it before you order a PCB.

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