HardLabs

Open motorcycle intercom

d3vv3·open-motorcycle-intercom·schematics/omi/omi.kicad_pcb

Open motorcycle intercom PCB layout, top view — open source ESP32 board by d3vv3

About the Open motorcycle intercom PCB

Open motorcycle intercom is an open source ESP32 PCB design by d3vv3, published on GitHub under the MIT license. It is a 4-layer board measuring 100 × 50 mm, with 116 components from 74 distinct parts.

Its main chip is the ESP32-S3-WROOM-1, from the ESP32 family. Other key parts include the NRF52840-QIAA-R, NRF21540-QDAA-R, BQ24074RGTR, TPS63020DSJR and USBLC6-2SC6. By type, the board carries 58 capacitors, 31 resistors, 9 ICs, 5 connectors, 4 inductors and 3 switches.

It belongs with the iot & wireless, audio and rf & radio designs in this gallery.

From the project

Open Source implementation for motorcycle intercoms. The cheapest way into mesh intercoms.

OpenHelmet is an open-source, motorcycle intercom system designed to outperform current proprietary solutions in latency, scalability, transparency, and hackability.

- Open protocol and open firmware - Commodity, off-the-shelf hardware - Use any microphone and any speakers from your existing helmet setup - Mesh networking for 4-8+ riders - Real-time full-duplex voice - 8-16 hours of active riding per charge - Bluetooth phone and media audio (calls, GPS, music, etc) - Interoperability with legacy Bluetooth intercoms (Cardo, Sena, etc.) via standard profiles

Main components on the Open motorcycle intercom

ESP32-S3-WROOM-1NRF52840-QIAA-RNRF21540-QDAA-RBQ24074RGTRTPS63020DSJRUSBLC6-2SC6PCM5102APWRMAX9814ETD+TTPA6132A2RTER

Open motorcycle intercom bill of materials (BOM)

116 components, 74 distinct parts — part numbers from the project's BOM.

QtyPartRefs
1
ESP32-S3-WROOM-1
Espressif Systems
U1
1
NRF52840-QIAA-R
Nordic Semiconductor
U2
1
NRF21540-QDAA-R
Nordic Semiconductor
U3
1
BQ24074RGTR
Texas Instruments
U4
1
TPS63020DSJR
Texas Instruments
U5
1
USBLC6-2SC6
STMicroelectronics
U6
1
PCM5102APWR
Texas Instruments
U7
1
MAX9814ETD+T
Analog Devices / Maxim Integrated
U8
1
TPA6132A2RTER
Texas Instruments
U9
1
C426985
32MHz 8pF
JGHC
Y1
1
C97606
32.768kHz 12.5pF
Seiko Instruments
Y2
1
C165948
USB-C
Korean Hroparts Elec
J4
1
C161691
LiPo + NTC
JST
J5
1
C145813
PJ-327C-4A Headphones
Korean Hroparts Electronics
J6
1
C145813
PJ-327C-4A Microphone
Korean Hroparts Electronics
J7
1
C492405
ESP FACTORY
XFCN
J8
1
2450AT18A100E
Johanson Technology
AE1
1
C318884
ESP RESET
XKB Connection
SW1
1
C318884
ESP BOOT
XKB Connection
SW2
1
C431540
POWER ON/OFF
SHOU HAN
SW3
Show 54 more
QtyPartRefs
1
C85402
PESD5V0S1UL CC1
Nexperia
D1
1
C85402
PESD5V0S1UL CC2
Nexperia
D2
1
C151296
SMF5.0A VBUS TVS
Littelfuse
D3
1
C713281
10uH >=100mA
Murata Electronics
L1
1
C3033018
XFL4020-152MEC 1.5uH
Coilcraft
L2
1
C206445
1.9nH RF (Nordic ref)
Murata Electronics
L3
1
C98044
3.0nH RF (Nordic ref)
Murata Electronics
L4
3
4.7UF
4.7uF
TDK
C23, C43, C44
11
100NF
100nF
Yageo
C24, C25, C26, C38, C47, C55, C57, C59 +3
1
C108079
100nF DEC1
Yageo
C27
1
C108079
100nF DEC2
Yageo
C28
1
C14665
100pF DEC3
Yageo
C29
1
C113807
1uF DEC4
Yageo
C30
1
C113807
1uF DEC5
Yageo
C31
1
C113807
1uF DEC6
Yageo
C32
1
C76639
4.7uF DECUSB
TDK
C33
2
12PF
12pF
Yageo
C34, C35
2
20PF
20pF
Yageo
C36, C37
4
10UF
10uF
CCTC
C39, C56, C58, C60
2
DNP antenna tune
C40, C41
8
1UF
1uF
Yageo
C42, C51, C66, C67, C68, C69, C74, C79
2
C380331
10uF 6.3V X5R
CCTC
C45, C46
3
C380336
22uF 6.3V X5R
CCTC
C48, C49, C50
2
C85893
1.0pF C0G RF (Nordic ref)
Murata Electronics
C52, C54
1
C88875
2.0pF C0G RF (Nordic ref)
Murata Electronics
C53
5
2.2UF
2.2uF
Yageo
C61, C62, C70, C71, C76
2
C107043
2.2nF C0G
Yageo
C64, C65
1
470NF
470nF
Yageo
C75
1
68NF
68nF
Yageo
C77
1
C170182
100nF C0G
Walsin
C78
1
DNP 1nF SHIELD
C80
1
C106228
0R antenna tune
YAGEO
R12
2
33R
UNI-ROYAL
R13, R14
3
10K
10k
UNI-ROYAL
R15, R25, R26
2
C23186
5.1k 1%
UNI-ROYAL
R16, R17
1
C22833
1.13k 1%
UNI-ROYAL
R18
1
C23041
4.12k 1%
UNI-ROYAL
R19
1
C23059
46.4k 1%
UNI-ROYAL
R20
1
DNP 10k TS fallback
UNI-ROYAL
R21
1
C22935
1M 1%
UNI-ROYAL
R22
1
C22827
180k 1%
UNI-ROYAL
R23
1
1M
UNI-ROYAL
R24
1
C155744
49.9R 1% ANT2 termination
Yageo
R27
1
C4216
33k FEM MODE
UNI-ROYAL
R28
2
470R
UNI-ROYAL
R29, R30
2
18K
18k
UNI-ROYAL
R31, R32
3
100K
100k
UNI-ROYAL
R33, R35, R37
1
150K
150k
UNI-ROYAL
R34
1
2.2K
2.2k
UNI-ROYAL
R36
1
C23345
22R USB D-
UNI-ROYAL
R38
1
C23345
22R USB D+
UNI-ROYAL
R39
1
C25803
100k USB100 default
UNI-ROYAL
R40
1
C25803
100k EN pulldown
UNI-ROYAL
R41
1
C21189
0R SHIELD BOND
UNI-ROYAL
R42

Open motorcycle intercom design files

The KiCad project lives in the d3vv3/open-motorcycle-intercom repository on GitHub; these links point at the commit this page was built from.

Open motorcycle intercom: common questions

What microcontroller does the Open motorcycle intercom use?

The Open motorcycle intercom is built around the ESP32-S3-WROOM-1, from the ESP32 family.

How big is the Open motorcycle intercom PCB?

The Open motorcycle intercom measures 100 × 50 mm, has 4 copper layers and is 1.6 mm thick.

How many components are on the Open motorcycle intercom?

116 components, from 74 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 Open motorcycle intercom design files?

From the d3vv3/open-motorcycle-intercom 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 Open motorcycle intercom design in my own project?

Yes, under the terms of its MIT license, which d3vv3 chose for the repository.

Can I test firmware for the Open motorcycle intercom without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug ESP32 firmware against it before you order a PCB.

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