Cheep3a
About the Cheep3a PCB
Cheep3a is an open source RISC-V PCB design by emeb, published on GitHub under the MIT license. It is a 4-layer board measuring 27.9 × 108 mm, with 84 components from 38 distinct parts.
Its main chip is the C5299908, from the RISC-V family. Other key parts include the C92004, C156291, C50282, C151064 and C266766. By type, the board carries 29 resistors, 27 capacitors, 9 connectors, 7 ICs, 3 diodes and 3 inductors.
It belongs with the audio designs in this gallery.
From the project
An inexpensive Eurorack audio generator
Version 0.1 of the design was fabbed and assembled by JLCPCB and several minor issues were discovered. These issues were corrected and the system performed as designed. Version 0.2 corrects the errors found in V0.1 but has not been built or tested.
Main components on the Cheep3a
Cheep3a bill of materials (BOM)
84 components, 38 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | C5299908 CH32V003F4U6 | QFN-20-1EP_3x3mm_P0.4mm_EP1.65x1.65mm_ThermalVias | U1 |
| 1 | C92004 PT8211-S | SO-8_3.9x4.9mm_P1.27mm | U2 |
| 1 | C156291 LM4040C50FTA | SOT-23 | U3 |
| 1 | C50282 MCP6004-I/ST | TSSOP-14_4.4x5mm_P0.65mm | U4 |
| 1 | C151064 ME6118A50B3G | SOT-223-3_TabPin2 | U5 |
| 1 | C266766 BCT2028EUK33 | SOT-23-5 | U6 |
| 1 | C6961 TL072CDT | SOIC-8_3.9x4.9mm_P1.27mm | U7 |
| 1 | C909754 MMBT3904 | SOT-23 | Q1 |
| 1 | C271630 SX32Y024000BK1T | Crystal_SMD_3225-4Pin_3.2x2.5mm | Y1 |
| 1 | PROGRAM | PinHeader_1x04_P2.54mm_Vertical | J1 |
| 1 | Conn_02x08_Odd_Even | con16_2X8_S4_TEC | J2 |
| 6 | AudioJack2_SwitchT | Jack_3.5mm_QingPu_WQP-PJ398SM_Vertical_CircularHoles | J3, J4, J6, J7, J8, J9 |
| 1 | JST SH-4 (Qwiic) | JST_SH_SM04B-SRSS-TB_04x1.00mm_Angled | J5 |
| 3 | 10k | Potentiometer_TT_P0915N | RV1, RV2, RV3 |
| 1 | SW_Push | SW_PUSH_6mm | SW1 |
| 2 | C2480 SS14 | D_SMA | D1, D2 |
| 1 | CLX6F-FKC | LED_RGB_PLCC-6 | D3 |
| 2 | C1017 GZ2012D601TF | L_0805_2012Metric | FB1, FB2 |
| 1 | C96697 GZ1608D222TF | L_0603_1608Metric | FB3 |
| 10 | C14663 0.1uf | C_0603_1608Metric | C1, C2, C3, C6, C7, C12, C13, C19 +2 |
Show 18 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 2 | C107045 27pf | C_0603_1608Metric | C4, C5 |
| 3 | C1664 330pf | C_0603_1608Metric | C8, C9, C17 |
| 4 | C15849 1uf | C_0603_1608Metric | C10, C11, C14, C26 |
| 3 | C440198 10uf | C_0805_2012Metric | C15, C16, C18 |
| 2 | C1613 3.3nf | C_0603_1608Metric | C20, C21 |
| 2 | C1594 160pf | C_0603_1608Metric | C24, C25 |
| 1 | C57112 10nf | C_0603_1608Metric | C27 |
| 1 | C4177 1.5k | R_0603_1608Metric | R1 |
| 6 | C25803 100k | R_0603_1608Metric | R2, R4, R10, R11, R22, R23 |
| 3 | C23184 49.9k | R_0603_1608Metric | R3, R5, R12 |
| 3 | C4216 33k | R_0603_1608Metric | R6, R7, R14 |
| 3 | C22828 180 | R_0603_1608Metric | R8, R9, R15 |
| 1 | C25804 10k | R_0603_1608Metric | R13 |
| 4 | C22790 12.5k | R_0603_1608Metric | R16, R17, R18, R19 |
| 2 | C23184 50k | R_0603_1608Metric | R20, R21 |
| 2 | C22775 100 | R_0603_1608Metric | R24, R25 |
| 1 | C22859 10 | R_0603_1608Metric | R26 |
| 3 | C21190 1k | R_0603_1608Metric | R27, R28, R29 |
Cheep3a design files
The KiCad project lives in the emeb/cheep3a repository on GitHub; these links point at the commit this page was built from.
Cheep3a: common questions
What microcontroller does the Cheep3a use?
The Cheep3a is built around the C5299908, from the RISC-V family.
How big is the Cheep3a PCB?
The Cheep3a measures 27.9 × 108 mm, has 4 copper layers and is 1.555 mm thick.
How many components are on the Cheep3a?
84 components, from 38 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 Cheep3a design files?
From the emeb/cheep3a 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 Cheep3a design in my own project?
Yes, under the terms of its MIT license, which emeb chose for the repository.
Can I test firmware for the Cheep3a without the hardware?
Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug RISC-V firmware against it before you order a PCB.
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