Audcalc

jonbro·Audcalc·Hardware/audcalc/audcalc.kicad_pcb

About the Audcalc PCB

Audcalc is an open source RP2040/RP2350 PCB design by jonbro, published on GitHub under the MIT license. It is a 4-layer board measuring 65 × 100 mm, with 214 components from 58 distinct parts.

Its main chip is the RP2040, from the RP2040/RP2350 family. Other key parts include the W25Q32JVSS, TLV320AIC3204, WMM7037AT2_mic, HCPL-0631 and MCP73831T-2ATI_OT. By type, the board carries 66 capacitors, 52 diodes, 35 resistors, 27 switches, 9 ICs and 9 jumpers.

It belongs with the audio designs in this gallery.

From the project

pocket sized groovebox

I'm happy with this, but its not 100% feature complete on the firmware side. Its really neat though, and I think you'll like it.

- RP2040 - 1/8in audio i/o - onboard mic - 104mm x 68mm x 14mm

The bom is contained within the Hardware kicad project, ready for assembly via jlcpcb. There are several additional items that must be sourced and handsoldered:

Audcalc, from the project README — From the project README

Main components on the Audcalc

W25Q32JVSS RP2040 TLV320AIC3204 WMM7037AT2_mic HCPL-0631 MCP73831T-2ATI_OT LM4040DBZ-2.5 ME6211C

Audcalc bill of materials (BOM)

214 components, 58 distinct parts.

Qty	Part	Footprint	Refs
1	W25Q32JVSS	SOIJ-8_5.3x5.3mm_Pitch1.27mm	U1
1	RP2040	RP2040-QFN-56	U2
1	TLV320AIC3204	QFN-32-1EP_5x5mm_Pitch0.5mm	U3
1	WMM7037AT2_mic	LGA-4 (3x3.8)	U4
1	HCPL-0631	SOIC-8_3.9x4.9mm_P1.27mm	U5
1	MCP73831T-2ATI_OT	SOT-23-5	U6
1	LM4040DBZ-2.5	SOT-23	U7
2	ME6211C	SOT-23-5	U9, U11
1	DMG2305UX-13	SOT-23-3	Q1
1	Q_PMOS_GSD	SOT-23	Q2
2	Q_NMOS_GSD	SOT-23	Q3, Q4
1	Crystal_GND24	Crystal_SMD_3225-4pin_3.2x2.5mm	Y1
1	picoprobe_debug	pico debug header	J1
1	USB_C_Receptacle_USB2.0	USB-C_SMD-TYPE-C-31-M-12	J2
1	line_in	HRO-PJ-327C-A	J3
1	headphone_out	HRO-PJ-327C-A	J4
1	midi_in	HRO-PJ-327C-A	J5
1	midi_out	HRO-PJ-327C-A	J6
1	battery	JST_PH_S2B-PH-SM4-TB_02x2.00mm_Angled	J7
1	Conn_01x02_Female	PinHeader_1x02_P2.54mm_Vertical	J8

Show 38 more

Qty	Part	Footprint	Refs
2	SolderJumper_2_Open	SolderJumper-2_P1.3mm_Open_RoundedPad1.0x1.5mm	JP1, JP2
7	SolderJumper_2_Bridged	SolderJumper-2_P1.3mm_Bridged_Pad1.0x1.5mm	JP3, JP4, JP5, JP6, JP7, JP8, JP14
2	R_POT_US	Potentiometer_Alps_RK09K_Horizontal	RV1, RV2
25	spst_4_pin_internal	ts1187	SW1, SW2, SW3, SW4, SW5, SW6, SW7, SW8 +17
2	spst_4_pin_internal_side	SKSCLDE010	SW26, SW27
1	128x32OLED	oled_ssd1306_14pin_91	LCD1
1	BAT54C	SOT-23	D1
1	LEDYellow	LED_0603	D2
4	D_Zener	D_SOD-323F	D3, D4, D5, D26
20	WS2812C-v1	ws2812b-2020-lightpipe	D6, D7, D8, D9, D10, D11, D12, D13 +12
24	D	D_SOD-323F_less_silk	D27, D28, D29, D30, D31, D32, D33, D34 +16
1	D_Schottky	D_SMA	D53
1	LED	LED_0603	D54
29	1u	C_0402_1005Metric	C1, C6, C7, C8, C9, C10, C11, C12 +21
14	100n	C_0402_1005Metric	C2, C3, C5, C26, C27, C28, C29, C30 +6
11	10u	C_0402_1005Metric	C4, C36, C38, C42, C43, C46, C50, C55 +3
2	30p	C_0402_1005Metric	C35, C37
4	.47u	C_0603_nosilk	C39, C44, C45, C47
2	47uf	C_1206	C48, C49
1	10u(tant)	CP_Tantalum_Case-A_EIA-3216-18_Reflow	C58
1	10n	C_0402_1005Metric	C59
1	100u	CP_EIA-3528-21_Kemet-B	C65
1	2u2	C_0402_1005Metric	C66
2	27.4	R_0402_1005Metric_nosilk	R1, R2
5	10k	R_0402_1005Metric_nosilk	R3, R9, R14, R24, R30
2	3.3k	R_0402_1005Metric_nosilk	R4, R5
4	1k	R_0402_1005Metric_nosilk	R6, R7, R17, R31
3	100k	R_0402_1005Metric_nosilk	R8, R18, R25
3	220	R_0402_1005Metric_nosilk	R10, R11, R21
3	33	R_0402_1005Metric_nosilk	R12, R34, R35
1	10	R_0402_1005Metric_nosilk	R13
1	330k	R_0402_1005Metric_nosilk	R15
1	4.7k	R_0402_1005Metric_nosilk	R16
3	5.1k	R_0402_1005Metric_nosilk	R19, R20, R23
2	330	R_0402_1005Metric_nosilk	R22, R26
2	1m	R_0402_1005Metric_nosilk	R27, R28
1	750k	C_0603_nosilk	R29
2	100	R_0402_1005Metric	R32, R33

Audcalc design files

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

LayoutHardware/audcalc/audcalc.kicad_pcb
SchematicHardware/audcalc/audcalc.kicad_sch

Audcalc: common questions

What microcontroller does the Audcalc use?

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

How big is the Audcalc PCB?

The Audcalc measures 65 × 100 mm, has 4 copper layers and is 1.6 mm thick.

How many components are on the Audcalc?

214 components, from 58 distinct parts. The full bill of materials is listed on this page.

Where can I download the Audcalc design files?

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

Can I use the Audcalc design in my own project?

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

Can I test firmware for the Audcalc 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.