# Portable USB MIDI Controller

## Description

Battery\-powered RP2350 MIDI controller with USB\-C USB\-MIDI, isolated 5\-pin DIN MIDI input, 5\-pin DIN MIDI output, four buttons, and an I²C OLED display\. Designed for accessible small\-to\-medium\-volume assembly using a Raspberry Pi Pico 2 module\.

## Project Details

- **Owner:** zilfawilby
- **Created:** 9/18/2026
- **Last Updated:** 9/18/2026
- **Visibility:** Public

## Key Components

### D1 — [1N4148WS RRG](https://flux.ai/lcsc/1n4148ws-rrg~ankm.md)

- Functional Group: MIDI IN
- Package or Case Code: SOD\-323\_L1\.7\-W1\.3\-LS2\.5\-RD\-1
- Role: Reverse Protection
- LCSC Part Number: C485027
- Manufacturer Name: Taiwan Semiconductor\(台湾半导体\)
- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/lcsc/2001151034\_Taiwan\-Semiconductor\-1N4148WS\-RRG\_C485027\.pdf
- Part Type: Switching Diode
- Manufacturer Part Number: 1N4148WS RRG
- Role Details: Antiparallel reverse\-voltage protection across MIDI IN optocoupler LED\.
- Product Info Url: https://lcsc\.com/product\-detail/New\-Arrivals\_Taiwan\-Semiconductor\-Taiwan\-Semicon\-1N4148WS\-RRG\_C485027\.html
- JLCPCB Part Class: Extended Part

**Pins:**
- 1 [pin 1]
- 2 [pin 2]

### D2 — [USBLC6\-2SC6](https://flux.ai/vasy_skral/usblc6-2sc6~g1b.md)

- Manufacturer Part Number: USBLC6\-2SC6
- Role Details: Low\-capacitance USB 2\.0 D\+/D\- ESD protection array adjacent to USB\-C connector\.
- Functional Group: USB\-C
- Symbol Style: parametric\-v1
- Role: Protection
- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Protection
- Manufacturer Name: STMicroelectronics
- Datasheet URL: https://www\.st\.com/content/ccc/resource/technical/document/datasheet/06/1d/48/9c/6c/20/4a/b2/CD00050750\.pdf/files/CD00050750\.pdf/jcr:content/translations/en\.CD00050750\.pdf
- LCSC Part Number: C7519

**Pins:**
- GND [pin 2]
- I/O1 [pin 6]
- I/O1 [pin 1]
- I/O2 [pin 3]
- I/O2 [pin 4]
- VBUS [pin 5]

### J1 — [B2B\-PH\-K\-S\(LF\)\(SN\)](https://flux.ai/lcsc/b2b-ph-k-slfsn~yvsw.md)

- Connector Positions: 2
- JLCPCB Part Class: Extended Part
- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/lcsc/2304140030\_JST\-B2B\-PH\-K\-S\-LF\-SN\_C131337\.pdf
- Part Type: Wire To Board / Wire To Wire Connector
- Role Details: Keyed JST\-PH connector for protected 1\-cell 1000 mAh LiPo; connector rated 2 A, battery/protection assumed at least 500 mA continuous\.
- Functional Group: Battery and Fuel Gauge
- Connector Gender: Male
- Manufacturer Part Number: B2B\-PH\-K\-S\(LF\)\(SN\)
- Manufacturer Name: JST
- Connector Rows: 1
- Package or Case Code: CONN\-TH\_B2B\-PH\-K\-S
- Connector Pitch: 2mm
- Product Info Url: https://lcsc\.com/product\-detail/PH\-Connectors\_JST\_B2B\-PH\-K\-S\-LF\-SN\_B2B\-PH\-K\-S\-LF\-SN\_C131337\.html
- LCSC Part Number: C131337
- Role: Battery Connector
- Connector Type: Wire To Board Connector

**Pins:**
- 1 [pin 1]
- 2 [pin 2]

### J2 — [S4B\-PH\-K\-S\(LF\)\(SN\)](https://flux.ai/jecstronic/s4b-ph-k-slfsn~kmr.md)

- Part Type: Connector
- Functional Group: OLED and I2C
- Datasheet URL: https://www\.jst\-mfg\.com/product/pdf/eng/ePH\.pdf
- Role: OLED Connector
- Manufacturer Part Number: S4B\-PH\-K\-S\(LF\)\(SN\)
- Role Details: Keyed 4\-pin JST\-PH cable connector for off\-board 0\.96\-inch 128x64 SSD1306\-compatible 3\.3 V I2C OLED: GND, 3V3, SCL, SDA\.
- Manufacturer Name: S4B\-PH\-K\-S\(LF\)\(SN\)
- License: https://creativecommons\.org/licenses/by/4\.0/

**Pins:**
- PIN\_1 [pin 1]
- PIN\_2 [pin 2]
- PIN\_3 [pin 3]
- PIN\_4 [pin 4]

### J3 — [SDS\-50J](https://flux.ai/adrian95/sds-50j.md)

- Manufacturer Name: Same Sky \(Formerly CUI Devices\)
- Functional Group: MIDI IN
- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/user\-uploaded/5c2003865f33cfcacbea373140b3a0d08aeb8beb6e890f6b895eea74d2c79276\.pdf
- Manufacturer Part Number: SDS\-50J
- Mount: Standard
- Role Details: Right\-angle through\-hole 5\-pin 180\-degree DIN receptacle for galvanically isolated MIDI input\.
- Part Type: Connector
- Role: MIDI IN Connector
- Symbol Style: parametric\-v1

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
- 4 [pin 4]
- 5 [pin 5]
- GND [pin E2]
- GND [pin E1]

### J4 — [SDS\-50J](https://flux.ai/adrian95/sds-50j.md)

- Manufacturer Name: Same Sky \(Formerly CUI Devices\)
- Functional Group: MIDI OUT
- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/user\-uploaded/5c2003865f33cfcacbea373140b3a0d08aeb8beb6e890f6b895eea74d2c79276\.pdf
- Manufacturer Part Number: SDS\-50J
- Mount: Standard
- Part Type: Connector
- Role: MIDI OUT Connector
- Role Details: Right\-angle through\-hole 5\-pin 180\-degree DIN receptacle for 3\.3 V standards\-compatible MIDI output\.
- Symbol Style: parametric\-v1

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
- 4 [pin 4]
- 5 [pin 5]
- GND [pin E2]
- GND [pin E1]

### J5 — [FTSH\-105\-01\-L\-DV\-K\-TR](https://flux.ai/jecstronic/ftsh-105-01-l-dv-k-tr~drj.md)

- Functional Group: Debug and Test
- Datasheet URL: https://suddendocs\.samtec\.com/catalog\_english/ftsh\_smt\.pdf
- Part Type: Connector
- Manufacturer Name: Samtec Inc\.
- Role: SWD Debug Header
- Manufacturer Part Number: FTSH\-105\-01\-L\-DV\-K\-TR
- License: https://creativecommons\.org/licenses/by/4\.0/
- Role Details: Compact 2x5 1\.27 mm Cortex\-style SWD access for VTREF, SWDIO, SWCLK, RESET and grounds\.

**Pins:**
- Pin\_1 [pin 01]
- Pin\_10 [pin 10]
- Pin\_2 [pin 02]
- Pin\_3 [pin 03]
- Pin\_4 [pin 04]
- Pin\_5 [pin 05]
- Pin\_6 [pin 06]
- Pin\_7 [pin 07]
- Pin\_8 [pin 08]
- Pin\_9 [pin 09]

### J6 — [USB4215\-03\-A](https://flux.ai/adrian95/usb4215-03-a~kg3.md)

- Datasheet URL: https://gct\.co/files/specs/usb4215\-spec\.pdf
- Part Type: USB C
- Role Details: Native USB 2\.0 device connector with VBUS input, independent CC1/CC2 sink pull\-downs and protected D\+/D\-\.
- Functional Group: USB\-C
- Symbol Style: parametric\-v1
- Package or Case Code: GCT\_USB4215\-03\-A\_REVA
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Name: GCT
- Role: Protection
- Manufacturer Part Number: USB4215\-03\-A

**Pins:**
- CC1 [pin A5]
- CC2 [pin B5]
- DN1 [pin A7]
- DN2 [pin B7]
- DP1 [pin A6]
- DP2 [pin B6]
- GND\_A [pin A1\_B12]
- GND\_B [pin B1\_A12]
- SBU1 [pin A8]
- SBU2 [pin B8]
- SHIELD [pin SH1]
- SHIELD [pin SH4]
- SHIELD [pin SH2]
- SHIELD [pin SH3]
- VBUS\_A [pin A4\_B9]
- VBUS\_B [pin B4\_A9]

### SW1 — [500SSP3S1M6QEA](https://flux.ai/adrian95/500ssp3s1m6qea~h6h.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://sten\-eswitch\-13110800\-production\.s3\.amazonaws\.com/system/asset/product\_line/data\_sheet/115/500\.pdf
- Manufacturer Name: E\-Switch
- Role Details: Battery disconnect switch in series with LiPo feed; current rating provides margin above 500 mA battery\-path requirement\.
- Functional Group: Battery and Fuel Gauge
- Manufacturer Part Number: 500SSP3S1M6QEA
- Role: Power Switch
- Part Type: Switch

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]

### SW2 — [PTS645SL43SMTR92 LFS](https://flux.ai/adrian95/pts645sl43smtr92-lfs~0ce.md)

- Package or Case Code: PTS645 Series 6x6 mm SMT Gull Wing
- License: https://creativecommons\.org/licenses/by/4\.0/
- Role Details: Normally\-open active\-low button to RP2350 GPIO; firmware uses internal pull\-up\.
- Functional Group: User Buttons
- Part Type: Switch
- Manufacturer Name: C&K
- Max Current: 0\.05A
- Operating Temperature: \-40°C to \+85°C
- Role: User Button
- Datasheet URL: https://www\.ckswitches\.com/media/1471/pts645\.pdf
- Manufacturer Part Number: PTS645SL43SMTR92 LFS

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
- 4 [pin 4]

### SW3 — [PTS645SL43SMTR92 LFS](https://flux.ai/adrian95/pts645sl43smtr92-lfs~0ce.md)

- Role: User Button
- Package or Case Code: PTS645 Series 6x6 mm SMT Gull Wing
- License: https://creativecommons\.org/licenses/by/4\.0/
- Functional Group: User Buttons
- Part Type: Switch
- Manufacturer Name: C&K
- Max Current: 0\.05A
- Operating Temperature: \-40°C to \+85°C
- Datasheet URL: https://www\.ckswitches\.com/media/1471/pts645\.pdf
- Role Details: Normally\-open active\-low button to RP2350 GPIO; firmware uses internal pull\-up\.
- Manufacturer Part Number: PTS645SL43SMTR92 LFS

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
- 4 [pin 4]

### SW4 — [PTS645SL43SMTR92 LFS](https://flux.ai/adrian95/pts645sl43smtr92-lfs~0ce.md)

- Package or Case Code: PTS645 Series 6x6 mm SMT Gull Wing
- License: https://creativecommons\.org/licenses/by/4\.0/
- Functional Group: User Buttons
- Role Details: Normally\-open active\-low button to RP2350 GPIO; firmware uses internal pull\-up\.
- Part Type: Switch
- Manufacturer Name: C&K
- Role: User Button
- Max Current: 0\.05A
- Operating Temperature: \-40°C to \+85°C
- Datasheet URL: https://www\.ckswitches\.com/media/1471/pts645\.pdf
- Manufacturer Part Number: PTS645SL43SMTR92 LFS

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
- 4 [pin 4]

### SW5 — [PTS645SL43SMTR92 LFS](https://flux.ai/adrian95/pts645sl43smtr92-lfs~0ce.md)

- Package or Case Code: PTS645 Series 6x6 mm SMT Gull Wing
- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Switch
- Role: User Button
- Role Details: Normally\-open active\-low button to RP2350 GPIO; firmware uses internal pull\-up\.
- Manufacturer Name: C&K
- Max Current: 0\.05A
- Operating Temperature: \-40°C to \+85°C
- Functional Group: User Buttons
- Datasheet URL: https://www\.ckswitches\.com/media/1471/pts645\.pdf
- Manufacturer Part Number: PTS645SL43SMTR92 LFS

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
- 4 [pin 4]

### TP1 — [S2761\-46R](https://flux.ai/silicon-yard/s2761-46r.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Role Details: Compact SMT probe access for power and key digital signals\.
- Datasheet URL: https://www\.harwin\.com/api/download/datasheet/S2761\-46R
- Functional Group: Debug and Test
- Role: Test Point
- Manufacturer Name: Harwin Inc\.
- Manufacturer Part Number: S2761\-46R
- Part Type: Test Point

**Pins:**
- \~ [pin 1]

### TP2 — [S2761\-46R](https://flux.ai/silicon-yard/s2761-46r.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Role Details: Compact SMT probe access for power and key digital signals\.
- Datasheet URL: https://www\.harwin\.com/api/download/datasheet/S2761\-46R
- Role: Test Point
- Manufacturer Name: Harwin Inc\.
- Manufacturer Part Number: S2761\-46R
- Functional Group: Debug and Test
- Part Type: Test Point

**Pins:**
- \~ [pin 1]

### TP3 — [S2761\-46R](https://flux.ai/silicon-yard/s2761-46r.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://www\.harwin\.com/api/download/datasheet/S2761\-46R
- Functional Group: Debug and Test
- Role: Test Point
- Manufacturer Name: Harwin Inc\.
- Manufacturer Part Number: S2761\-46R
- Role Details: Compact SMT probe access for power and key digital signals\.
- Part Type: Test Point

**Pins:**
- \~ [pin 1]

### TP4 — [S2761\-46R](https://flux.ai/silicon-yard/s2761-46r.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Functional Group: Debug and Test
- Datasheet URL: https://www\.harwin\.com/api/download/datasheet/S2761\-46R
- Role: Test Point
- Role Details: Compact SMT probe access for power and key digital signals\.
- Manufacturer Name: Harwin Inc\.
- Manufacturer Part Number: S2761\-46R
- Part Type: Test Point

**Pins:**
- \~ [pin 1]

### TP5 — [S2761\-46R](https://flux.ai/silicon-yard/s2761-46r.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Role Details: Compact SMT probe access for power and key digital signals\.
- Datasheet URL: https://www\.harwin\.com/api/download/datasheet/S2761\-46R
- Manufacturer Name: Harwin Inc\.
- Manufacturer Part Number: S2761\-46R
- Role: Test Point
- Functional Group: Debug and Test
- Part Type: Test Point

**Pins:**
- \~ [pin 1]

### TP6 — [S2761\-46R](https://flux.ai/silicon-yard/s2761-46r.md)

- Role Details: Compact SMT probe access for power and key digital signals\.
- License: https://creativecommons\.org/licenses/by/4\.0/
- Functional Group: Debug and Test
- Datasheet URL: https://www\.harwin\.com/api/download/datasheet/S2761\-46R
- Manufacturer Name: Harwin Inc\.
- Manufacturer Part Number: S2761\-46R
- Role: Test Point
- Part Type: Test Point

**Pins:**
- \~ [pin 1]

### TP7 — [S2761\-46R](https://flux.ai/silicon-yard/s2761-46r.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Role Details: Compact SMT probe access for power and key digital signals\.
- Datasheet URL: https://www\.harwin\.com/api/download/datasheet/S2761\-46R
- Functional Group: Debug and Test
- Manufacturer Name: Harwin Inc\.
- Manufacturer Part Number: S2761\-46R
- Role: Test Point
- Part Type: Test Point

**Pins:**
- \~ [pin 1]

### TP8 — [S2761\-46R](https://flux.ai/silicon-yard/s2761-46r.md)

- Functional Group: Debug and Test
- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://www\.harwin\.com/api/download/datasheet/S2761\-46R
- Manufacturer Name: Harwin Inc\.
- Manufacturer Part Number: S2761\-46R
- Role Details: Compact SMT probe access for power and key digital signals\.
- Part Type: Test Point
- Role: Test Point

**Pins:**
- \~ [pin 1]

### U10 — [TPS63031DSKR](https://flux.ai/adrian95/tps63031dskr~yd3.md)

- Manufacturer Name: Texas Instruments
- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://www\.ti\.com/lit/ds/symlink/tps63030\.pdf
- Manufacturer Part Number: TPS63031DSKR
- Role Details: Fixed 3\.3 V buck\-boost from charger SYS rail; supports 250 mA peak load with margin across single\-cell battery range\.
- Role: Power Conversion
- Part Type: Integrated Circuit
- Functional Group: Power Path and Charging

**Pins:**
- EN [pin 6]
- EP [pin 11]
- FB [pin 10]
- GND [pin 9]
- L1 [pin 4]
- L2 [pin 2]
- PGND [pin 3]
- PS/SYNC [pin 7]
- VIN [pin 5]
- VINA [pin 8]
- VOUT [pin 1]

### U2 — [MAX17048G\+T10](https://flux.ai/lcsc/max17048gplust10~jvyd.md)

- Manufacturer Name: MAXIM
- Manufacturer Part Number: MAX17048G\+T10
- Role Details: I2C state\-of\-charge monitor for protected 1\-cell 1000 mAh LiPo on shared I2C bus\.
- LCSC Part Number: C2682616
- Functional Group: Battery and Fuel Gauge
- Package or Case Code: DFN\-8\_L2\.0\-W2\.0\-P0\.50\-BL\-EP
- Datasheet URL: https://www\.analog\.com/media/en/technical\-documentation/data\-sheets/MAX17048\-MAX17049\.pdf
- Role: Fuel Gauge
- Part Type: Battery Management ICs
- Symbol Style: parametric\-v1
- JLCPCB Part Class: Extended Part

**Pins:**
- \~\{ALRT\} [pin 5]
- CELL [pin 2]
- CTG [pin 1]
- EP [pin 9]
- GND [pin 4]
- QSTRT [pin 6]
- SCL [pin 7]
- SDA [pin 8]
- VDD [pin 3]

### U3 — [ACPL\-M21L\-500E](https://flux.ai/adrian95/acpl-m21l-500e~lpv.md)

- Role: MIDI Input Isolation
- Manufacturer Part Number: ACPL\-M21L\-500E
- Manufacturer Name: Broadcom Limited
- Datasheet URL: https://www\.mouser\.com/datasheet/2/678/AV02\_3462EN\_2020\_11\_2\-1828446\.pdf
- Part Type: Isolator
- Role Details: 5 MBd logic\-output optocoupler for galvanically isolated 31\.25 kbaud MIDI IN, operated from 3\.3 V logic rail\.
- License: https://creativecommons\.org/licenses/by/4\.0/
- Functional Group: MIDI IN

**Pins:**
- Anode [pin 1]
- Cathode [pin 3]
- GND [pin 4]
- VDD [pin 6]
- VO [pin 5]

### U4 — [SN74LVC1G17QDCKRQ1](https://flux.ai/adrian95/sn74lvc1g17qdckrq1~8n.md)

- Datasheet URL: https://www\.ti\.com/general/docs/suppproductinfo\.tsp?distId=10&gotoUrl=https%3A%2F%2Fwww\.ti\.com%2Flit%2Fgpn%2Fsn74lvc1g17\-q1
- Role Details: 3\.3 V non\-inverting Schmitt buffer driving standards\-compatible MIDI OUT current loop at 31\.25 kbaud\.
- Manufacturer Name: Texas Instruments
- Manufacturer Part Number: SN74LVC1G17QDCKRQ1
- License: https://creativecommons\.org/licenses/by/4\.0/
- Functional Group: MIDI OUT
- Part Type: Integrated Circuit
- Role: MIDI Output Driver

**Pins:**
- A [pin 2]
- GND [pin 3]
- NC [pin 1]
- VCC [pin 5]
- Y [pin 4]

### U5 — [SN74LVC1G14DCKRG4](https://flux.ai/lcsc/sn74lvc1g14dckrg4~qhoj.md)

- Manufacturer Part Number: SN74LVC1G14DCKRG4
- Functional Group: MIDI IN
- Package or Case Code: SC\-70\-5\_L2\.1\-W1\.3\-P0\.65\-LS2\.1\-BR
- Role Details: Inverts ACPL\-M21L active\-high optocoupler output so RP2350 UART RX has standard idle\-high/start\-low polarity\.
- Role: Logic\-level Shifting
- Manufacturer Name: TI\(德州仪器\)
- LCSC Part Number: C2872446

**Pins:**
- A [pin 2]
- GND [pin 3]
- NC [pin 1]
- VCC [pin 5]
- Y [pin 4]

### U6 — [RP2350B](https://flux.ai/vasy_skral/rp2350b~1qq.md)

- Functional Group: Compute Core
- Role Details: Bare RP2350B compute core; custom onboard design with external flash, PSRAM, USB\-C, clock, power and debug support\.
- Symbol Style: Parametric
- Manufacturer Name: Raspberry Pi Ltd
- Compliance: RoHS,REACH,Conflict Minerals
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: RP2350B
- Package or Case Code: QFN50P1200X1200X80\-81WN
- Datasheet URL: https://cdn2\.flux\.ai/copilot\-datasheets/pdf\-upload\-42b1ac17fa99447872bb75334a75d2fe3396182f51790cdbf9b88e022ed43904/e095863baea4b32fe411f947dac8ff446ed7060b942529871db787c2bbf56cd5\.pdf?GoogleAccessId=graviton\-mvp%40appspot\.gserviceaccount\.com&Expires=4876807597&Signature=XC2kq7swDloo1naI9XLpMuwVUQhWP2kldbcQM872YiEeB5Q30AKJw3q4FbjFb%2BKheABTyLMicdGXku2t1NJZZdblvYfIZ8fJMDDIYjHrji0bVjrg75S8VLxO6oMqxOlQEo6P02%2BWLK81T%2F8qfwHkfxrj96wOI59eP5bY0WxZwUSTdFKbxOoG5tcslcHcXGwdIrW9LrGkL1F%2BY1JnWlIfdpDnvXeGaMoG1BoBHThQAOUOBmXeszzLd9d1xzhxsdkZY2rFhrwcLLkuJl0DBFqwg2Vr%2FUA9tzrpjIbR%2FO0mOuFU64rsABqZDUm8g%2FWoTOCxwQrd%2BHOU6gIQ8lvLYk4W2Q%3D%3D
- Role: Logic\-level Shifting
- Part Type: Microcontroller

**Pins:**
- ADC\_AVDD [pin 59]
- DVDD [pin 51]
- DVDD [pin 32]
- DVDD [pin 10]
- GND [pin 81]
- GPIO0 [pin 77]
- GPIO1 [pin 78]
- GPIO10 [pin 8]
- GPIO11 [pin 9]
- GPIO12 [pin 11]
- GPIO13 [pin 12]
- GPIO14 [pin 13]
- GPIO15 [pin 14]
- GPIO16 [pin 16]
- GPIO17 [pin 17]
- GPIO18 [pin 18]
- GPIO19 [pin 19]
- GPIO2 [pin 79]
- GPIO20 [pin 20]
- GPIO21 [pin 21]
- GPIO22 [pin 22]
- GPIO23 [pin 23]
- GPIO24 [pin 25]
- GPIO25 [pin 26]
- GPIO26 [pin 27]
- GPIO27 [pin 28]
- GPIO28 [pin 36]
- GPIO29 [pin 37]
- GPIO3 [pin 80]
- GPIO30 [pin 38]
- GPIO31 [pin 39]
- GPIO32 [pin 40]
- GPIO33 [pin 42]
- GPIO34 [pin 43]
- GPIO35 [pin 44]
- GPIO36 [pin 45]
- GPIO37 [pin 46]
- GPIO38 [pin 47]
- GPIO39 [pin 48]
- GPIO4 [pin 1]
- GPIO40\_ADC0 [pin 49]
- GPIO41\_ADC1 [pin 52]
- GPIO42\_ADC2 [pin 53]
- GPIO43\_ADC3 [pin 54]
- GPIO44\_ADC4 [pin 55]
- GPIO45\_ADC5 [pin 56]
- GPIO46\_ADC6 [pin 57]
- GPIO47\_ADC7 [pin 58]
- GPIO5 [pin 2]
- GPIO6 [pin 3]
- GPIO7 [pin 4]
- GPIO8 [pin 6]
- GPIO9 [pin 7]
- IOVDD [pin 60]
- IOVDD [pin 29]
- IOVDD [pin 76]
- IOVDD [pin 5]
- IOVDD [pin 50]
- IOVDD [pin 15]
- IOVDD [pin 24]
- IOVDD [pin 41]
- QSPI\_IOVDD [pin 69]
- QSPI\_SCLK [pin 71]
- QSPI\_SD0 [pin 72]
- QSPI\_SD1 [pin 74]
- QSPI\_SD2 [pin 73]
- QSPI\_SD3 [pin 70]
- QSPI\_SS [pin 75]
- RUN [pin 35]
- SWCLK [pin 33]
- SWDIO [pin 34]
- USB\_DM [pin 66]
- USB\_DP [pin 67]
- USB\_OTP\_VDD [pin 68]
- VREG\_AVDD [pin 61]
- VREG\_FB [pin 65]
- VREG\_LX [pin 63]
- VREG\_PGND [pin 62]
- VREG\_VIN [pin 64]
- XIN [pin 30]
- XOUT [pin 31]

### U7 — [W25Q128JVPIM TR](https://flux.ai/lcsc/w25q128jvpim-tr~0ia5.md)

- LCSC Part Number: C2441427
- Functional Group: Compute Memory
- JLCPCB Part Class: Extended Part
- Package or Case Code: WSON\-8\_L6\.0\-W5\.0\-P1\.27\-BL\-EP
- Manufacturer Part Number: W25Q128JVPIM TR
- Role Details: 16 MB QSPI NOR execute\-in\-place program flash for RP2350B\.
- Manufacturer Name: WINBOND\(华邦\)
- Role: Energy Storage

**Pins:**
- /CS [pin 1]
- /HOLDor/RESET\(IO3\) [pin 7]
- /WP\(IO2\) [pin 3]
- CLK [pin 6]
- DI\(IO0\) [pin 5]
- DO\(IO1\) [pin 2]
- EP [pin 9]
- GND [pin 4]
- VCC [pin 8]

### U8 — [APS6404L\-3SQR\-ZR](https://flux.ai/adrian95/aps6404l-3sqr-zr~49q.md)

- Manufacturer Name: AP Memory
- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://www\.mouser\.com/datasheet/2/1127/APM\_PSRAM\_QSPI\_APS6404L\_3SQR\_v2\_3\_PKG\-1954826\.pdf
- Role: Energy Storage
- Functional Group: Compute Memory
- Role Details: 8 MB QSPI PSRAM compatible with RP2350/Pico ecosystem, connected on GPIO\-controlled secondary QSPI interface\.
- Package or Case Code: PSON50P200X300X50\-9N
- Part Type: DRAM
- Manufacturer Part Number: APS6404L\-3SQR\-ZR

**Pins:**
- \~CE [pin 1]
- EXP [pin 9]
- SCLK [pin 6]
- SI/SIO\(0\) [pin 5]
- SIO\(2\) [pin 3]
- SIO\(3\) [pin 7]
- SO/SIO\(1\) [pin 2]
- VDD [pin 8]
- VSS [pin 4]

### U9 — [BQ24074RGTT](https://flux.ai/lcsc/bq24074rgtt~fpyl.md)

- Datasheet URL: https://www\.ti\.com/lit/ds/symlink/bq24074\.pdf
- Role: Power Conversion
- Role Details: Single\-cell LiPo charger with dynamic power\-path management; input path rated up to 1\.5 A, charge target 500 mA, system peak design load 250 mA\.
- Part Type: Battery Management ICs
- Functional Group: Power Path and Charging
- JLCPCB Part Class: Extended Part
- Package: VQFN\-16 RGT \(3 mm × 3 mm\) with exposed thermal pad
- Implementation Details: Standalone single\-cell Li\-Ion/Li\-Polymer linear charger and power\-path management IC; 4\.2 V battery regulation, 4\.4 V OUT regulation, 10\.5 V OVP, 1\.5 A programmable fast charge/input current limit\.
- LCSC Part Number: C2861252
- Operating Voltage: IN operating range 4\.35–10\.2 V for BQ24074; IN withstand/recommended range up to 26 V, abs max 28 V
- License: https://creativecommons\.org/licenses/by/4\.0/
- Symbol Style: parametric\-v1
- Operating Temperature: \-40 to 85°C
- Manufacturer Part Number: BQ24074RGTT
- Package or Case Code: VQFN\-16\_L3\.0\-W3\.0\-P0\.50\-TL\-EP1\.7
- Manufacturer Name: Texas Instruments

**Pins:**
- \~\{CE\} [pin 4]
- \~\{CHG\} [pin 9]
- \~\{PGOOD\} [pin 7]
- BAT [pin 2]
- BAT [pin 3]
- EN1 [pin 6]
- EN2 [pin 5]
- EP [pin 17]
- ILIM [pin 12]
- IN [pin 13]
- ISET [pin 16]
- ITERM [pin 15]
- OUT [pin 11]
- OUT [pin 10]
- TMR [pin 14]
- TS [pin 1]
- VSS [pin 8]

### Y1 — [ABM8\-12\.000MHZ\-B2\-T](https://flux.ai/adrian95/abm8-12p000mhz-b2-t~rot.md)

- Manufacturer Name: Abracon
- Datasheet URL: https://mm\.digikey\.com/Volume0/opasdata/d220001/medias/docus/6536/ABM8\_Datasheet\.pdf
- Frequency: 12MHz
- Manufacturer Part Number: ABM8\-12\.000MHZ\-B2\-T
- License: https://creativecommons\.org/licenses/by/4\.0/
- Package or Case Code: XTAL\_ABM8\-12\.000MHZ\-B2\-T
- Role Details: 12 MHz RP2350 reference crystal, 18 pF load specification\.
- Part Type: Oscillator
- Functional Group: Compute Core
- Role: Signal Generation

**Pins:**
- \~ [pin 3]
- \~ [pin 1]
- GND [pin 2]
- GND\_\_1 [pin 4]

*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://flux\.ai/zilfawilby/portable\-usb\-midi\-controller\~hq](https://flux.ai/zilfawilby/portable-usb-midi-controller~hq).*

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*Generated from [https://flux\.ai/zilfawilby/portable\-usb\-midi\-controller\~hq](https://flux.ai/zilfawilby/portable-usb-midi-controller~hq)*