Frohne
About the Frohne PCB
Frohne is an open source RP2040/RP2350 PCB design by frohro, published on GitHub. It is a 4-layer board measuring 100 × 100 mm, with 215 components from 69 distinct parts.
Its main chip is the Pico, from the RP2040/RP2350 family. Other key parts include the CJC4334H, PCM1808PWR, MS5351M, OPA1612AxD and L78M05ABDT-TR. By type, the board carries 69 jumpers, 54 capacitors, 38 resistors, 16 test points, 11 connectors and 8 ICs.
From the project
This is the class project for the EE/CPTR section of Intro-to-CAD in 2026.
Open Hardware/Intro-to-CAD-2026.kicadpro`.
See Software/SDR/firmware/README.md if the firmware folder is empty.
Main components on the Frohne
Frohne bill of materials (BOM)
215 components, 69 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | CJC4334H | SOIC-8_3.9x4.9mm_P1.27mm | U1 |
| 1 | PCM1808PWR | TSSOP-14_4.4x5mm_P0.65mm | U2 |
| 1 | Pico | RPi_Pico_SMD_TH | U3 |
| 1 | MS5351M | MSOP-10_3x3mm_P0.5mm | U4 |
| 2 | OPA1612AxD | SOIC-8_3.9x4.9mm_P1.27mm | U5, U8 |
| 1 | L78M05ABDT-TR STMicroelectronics | TO-252-2_L6.5-W6.1-P4.58-LS10.0-TL | U6 |
| 1 | SN74CBT3253 | SSOP-16_3.9x4.9mm_P0.635mm | U7 |
| 1 | AO3401A Alpha & Omega Semicon | Q_SOT-23 | Q1 |
| 1 | YC24.576MUBCE2O | Oscillator_SMD_Abracon_ASE-4Pin_3.2x2.5mm | X1 |
| 1 | ADC IN | Jack_3.5mm_CUI_SJ-3523-SMT_Horizontal | J1 |
| 1 | Conn_02x20_Counter_Clockwise | PinSocket_2x20_P2.54mm_Vertical_pins1-20 | J2 |
| 1 | Conn_02x20_Counter_Clockwise | PinSocket_2x20_P2.54mm_Vertical_Counterclockwise_pins21-40 | J3 |
| 1 | Conn_01x20_Socket | PinSocket_1x20_P2.54mm_Vertical | J4 |
| 1 | +12V | PinHeader_1x02_P2.54mm_Vertical | J5 |
| 1 | Conn_01x01_Pin | PinHeader_1x01_P2.54mm_Vertical | J7 |
| 1 | OSC OUT | BNC_TEConnectivity_1478204_Vertical | J8 |
| 1 | DAC OUT | Jack_3.5mm_CUI_SJ-3523-SMT_Horizontal | J9 |
| 1 | Conn_01x20_Socket | PinSocket_1x20_P2.54mm_Vertical-pins21-40 | J10 |
| 1 | SDR ANT | BNC_TEConnectivity_1478204_Vertical | J11 |
| 1 | SDR Out | Jack_3.5mm_CUI_SJ-3523-SMT_Horizontal | J12 |
Show 49 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 64 | Jumper_2_Bridged | SolderJumper-2_P1.3mm_Bridged2Bar_RoundedPad1.0x1.5mm | JP1, JP20, JP21, JP22, JP23, JP24, JP25, JP26 +56 |
| 1 | ~ | SolderJumper-2_P1.3mm_Open_RoundedPad1.0x1.5mm | JP2 |
| 3 | GND_LP_SND | SolderJumper-2_P1.3mm_Open_RoundedPad1.0x1.5mm | JP18, JP19, JP88 |
| 1 | USB Only | SolderJumper-2_P1.3mm_Open_RoundedPad1.0x1.5mm | JP50 |
| 1 | Filter | PinHeader_1x04_P2.54mm_Vertical | Je3 |
| 1 | RST XUNPU | SW_TS-1088-AR02016 | S1 |
| 1 | L | TestPoint_THTPad_D1.5mm_Drill0.7mm | TP1 |
| 1 | R | TestPoint_THTPad_D1.5mm_Drill0.7mm | TP2 |
| 1 | I LO | TestPoint_THTPad_D1.5mm_Drill0.7mm | TP3 |
| 1 | Q LO | TestPoint_THTPad_D1.5mm_Drill0.7mm | TP4 |
| 1 | OSC | TestPoint_THTPad_D1.5mm_Drill0.7mm | TP5 |
| 1 | 180 | TestPoint_THTPad_D1.5mm_Drill0.7mm | TP6 |
| 1 | 270 | TestPoint_THTPad_D1.5mm_Drill0.7mm | TP7 |
| 2 | GND | TestPoint_THTPad_D1.5mm_Drill0.7mm | TP10, TP12 |
| 1 | VA/2 | TestPoint_THTPad_D1.5mm_Drill0.7mm | TP11 |
| 1 | 0 | TestPoint_THTPad_D1.5mm_Drill0.7mm | TP14 |
| 1 | 90 | TestPoint_THTPad_D1.5mm_Drill0.7mm | TP16 |
| 1 | I | TestPoint_THTPad_D1.5mm_Drill0.7mm | TP17 |
| 1 | Q | TestPoint_THTPad_D1.5mm_Drill0.7mm | TP18 |
| 1 | +5 | TestPoint_THTPad_D1.5mm_Drill0.7mm | TP25 |
| 1 | VDDA | TestPoint_THTPad_D1.5mm_Drill0.7mm | TP26 |
| 1 | H1102NLT | XFMR_H1102NLT | TR1 |
| 1 | SGM2205-ADJXTDB8G/TR | DFN-8-1EP_3x3mm_P0.65mm_EP1.55x2.4mm | e1 |
| 3 | Groundloop_Insurance | SolderJumper-2_P1.3mm_Bridged_RoundedPad1.0x1.5mm | e3, e4, e5 |
| 3 | SS14 MDD（Microdiode Electronics） | D_SMA | D1, D2, D3 |
| 7 | ~ Sunlord | FB_0805 | FB1, FB2, FB3, FB4, FB5, FB6, FB7 |
| 16 | 100nF Samsung Electro-Mechanics | C_0805 | C1, C10, C11, C12, C13, C15, C20, C23 +8 |
| 7 | 10uF Samsung Electro-Mechanics | C_1206 | C2, C5, C33, C34, C35, C41, C42 |
| 4 | 1uF Samsung Electro-Mechanics | C_0805 | C3, C4, C21, C29 |
| 4 | 2.2nF Samsung Electro-Mechanics | C_0805 | C6, C7, C49, C53 |
| 5 | 10uF AVX | C_CASE-A-3216-18(mm) | C8, C9, C39, C44, C45 |
| 8 | 330pF Samsung Electro-Mechanics | C_0603 | C14, C16, C19, C22, C24, C25, C26, C27 |
| 5 | 100uF AVX | C_CASE-B-3528-21(mm) | C17, C36, C37, C46, C47 |
| 2 | 100pF Samsung Electro-Mechanics | C_0805 | C18, C28 |
| 1 | 4.7pF FH(Guangdong Fenghua Advanced Tech) | C_0603 | C40 |
| 2 | 0.1u | C_0805_2012Metric | C43, C55 |
| 6 | 10kΩ UNI-ROYAL(Uniroyal Elec) | R_0805 | R1, R4, R12, R13, R31, R32 |
| 2 | 430Ω UNI-ROYAL(Uniroyal Elec) | R_0603 | R2, R3 |
| 1 | 33kΩ UNI-ROYAL(Uniroyal Elec) | R_0805 | R5 |
| 1 | 12kΩ UNI-ROYAL(Uniroyal Elec) | R_0805 | R6 |
| 5 | 1Ω UNI-ROYAL(Uniroyal Elec) | R_0805 | R7, R10, R11, R20, R21 |
| 2 | 47Ω UNI-ROYAL(Uniroyal Elec) | R_0805 | R8, R9 |
| 3 | 10Ω UNI-ROYAL(Uniroyal Elec) | R_0603 | R14, R19, R30 |
| 2 | 4.7kΩ UNI-ROYAL(Uniroyal Elec) | R_0805 | R15, R23 |
| 8 | 33Ω UNI-ROYAL(Uniroyal Elec) | R_0805 | R16, R17, R18, R34, R35, R36, R37, R38 |
| 2 | 560Ω UNI-ROYAL(Uniroyal Elec) | R_0805 | R22, R33 |
| 4 | 100Ω UNI-ROYAL(Uniroyal Elec) | R_0805 | R24, R25, R26, R27 |
| 1 | 100kΩ UNI-ROYAL(Uniroyal Elec) | R_0805 | R28 |
| 1 | 20kΩ UNI-ROYAL(Uniroyal Elec) | R_0805 | R29 |
Frohne design files
The KiCad project lives in the frohro/Intro-to-CAD-2026 repository on GitHub; these links point at the commit this page was built from.
Frohne: common questions
What microcontroller does the Frohne use?
The Frohne is built around the Pico, from the RP2040/RP2350 family.
How big is the Frohne PCB?
The Frohne measures 100 × 100 mm, has 4 copper layers and is 1.6 mm thick.
How many components are on the Frohne?
215 components, from 69 distinct parts. The full bill of materials is listed on this page.
Where can I download the Frohne design files?
From the frohro/Intro-to-CAD-2026 repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.
Can I use the Frohne design in my own project?
The repository has no license, so all rights stay with frohro. Use it as a reference, and ask the author before reusing the design.
Can I test firmware for the Frohne 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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