Raspberry Pi HAT Design

0:00

Work completed
  • Removed Waveshare connector and associated nets
  • Added raw 2.9" e-paper FPC connector placeholder (J2) with pins Gx, Sx, VCOM, VGL, VGH, VDD, RES, CLK, DIN, CS, AUX
  • Placed TI TPS65185RSLR as the e-paper driver (U6)
  • Added supporting passive components:
    • Capacitors C17, C18, C19, C20, C21
    • Series damping resistor R9 on SCLK
    • Pull-ups R10 on BUSY and R11 on RST
  • Wired PMIC power rails:
    • U6:VGH to FPC VGH
    • U6:VGL to FPC VGL
    • U6:VCOM to FPC VCOM
    • U6:VIN to boost converter 5 V net
    • U6:VIN3P3 to Pi 3.3 V net
  • Rewired Pi SPI and control lines:
    • MOSI, MISO, SCLK (via R9), CS, DC, RST, BUSY remapped to J2 pins
  • Added test points for MOSI, MISO, SCK, CS, DC, RST, BUSY
  • Renamed nets to PANEL_MOSI, PANEL_MISO, PANEL_SCLK, PANEL_CS, PANEL_DC, PANEL_BUSY
  • Documented FPC connector orientation and added layout keepout note: "Maintain 5 mm clearance for high-voltage nets (VGH, VGL, VCOM)"
Success criteria
✅ Waveshare connector replaced with raw FPC connector ✅ High-voltage rails implemented via PMIC ✅ SPI (with series damping) and control signals correctly rewired ✅ ERC passes and BOM placeholders integrated
Next step Prepare PCB layout: review footprints, set up stackup, place components, and run Auto-Layout for routing.
175 days

J1 GPIO 17 - J2 6
J1 GPIO3 (I2C1 SCL) - U2 SCLK/SCL
J1 GPIO 17 - J2 6
C2 P1 - U1 VI
C3 P2 - L1 P2
J1 GPIO 20 (PCM Data-In) - U4 SD
J1 GPIO 19 (PCM Frame Sync) - U4 WS
R6 P2 - U4 CLOCK
J1 GPIO 10 (SPI0 MOSI) - J2 1
J1 GPIO 8 (SPI Chip Select 0) - J2 4
J1 GPIO 20 (PCM Data-In) - U4 SD
J1 GPIO 9 (SPI0 MISO) - J2 2
J1 GPIO 11 (SPI0 SCLK) - J2 8
J1 GPIO 20 (PCM Data-In) - U4 SD
J1 GPIO 17 - J2 6
J1 GPIO 17 - J2 6
J1 GPIO 17 - J2 6
R7 P2 - U4 CLOCK
J1 GPIO 17 - J2 6
J1 GPIO 9 (SPI0 MISO) - J2 2
R6 P2 - U4 CLOCK
J1 GPIO 8 (SPI Chip Select 0) - J2 4
J1 GPIO3 (I2C1 SCL) - U2 SCLK/SCL
J1 GPIO 17 - J2 6
J1 GPIO 17 - J2 6
J1 GPIO 17 - J2 6
U1 VOUT - J1 5V PWR
J1 3v3 - C4 P1
J1 GPIO 19 (PCM Frame Sync) - U4 WS
J1 GPIO 11 (SPI0 SCLK) - J2 3
J1 GPIO2 (I2C1 SDA) - U2 MISO/SDA
J1 GPIO 17 - J2 6
R6 P2 - U4 CLOCK
J1 3v3 - C4 P1
J1 GPIO 17 - J2 6
U1 VOUT - J1 5V PWR
J1 GPIO 17 - J2 6
J1 GPIO 17 - J2 6
J1 GPIO 11 (SPI0 SCLK) - J2 3
J1 GPIO 11 (SPI0 SCLK) - J2 8
J1 GPIO 18 (PCM Clock) - U4 SCK
J1 GPIO 17 - J2 6
J1 3v3 - C4 P1
R6 P2 - U4 CLOCK
J1 GPIO 20 (PCM Data-In) - U4 SD
J1 GPIO 18 (PCM Clock) - U4 SCK
J1 GPIO2 (I2C1 SDA) - U2 MISO/SDA
J1 GPIO 11 (SPI0 SCLK) - J2 3
J1 GPIO 10 (SPI0 MOSI) - J2 1
R7 P2 - U4 CLOCK
J1 GPIO 17 - J2 6
J1 GPIO 17 - J2 6
J1 GPIO 20 (PCM Data-In) - U4 SD
U1 VOUT - J1 5V PWR
J1 GPIO 17 - J2 6
J1 GPIO 20 (PCM Data-In) - U4 SD
C16
Capacitance
Capacitance
C20
Capacitance
Capacitance
C18
Capacitance
Capacitance
C15
Capacitance
Capacitance
C13
Capacitance
Capacitance
C11
Capacitance
Capacitance
C18
Capacitance
Capacitance
C19
Capacitance
Capacitance
C17
Capacitance
Capacitance
C17
Capacitance
Capacitance
C8
Capacitance
100nF
C14
Capacitance
Capacitance
C21
Capacitance
Capacitance
C9
Capacitance
100nF
C12
Capacitance
Capacitance
C10
Capacitance
Capacitance
C19
Capacitance
Capacitance
U5
U2
Not Recommended for New Designs
J1
MK1
U4
MK2
TP_MOSI
GND
U3
TP_MISO
TP_SCK
Hole4
Hole3
Hole2
Hole1
U1


  • Ground
    A common return path for electric current. Commonly known as ground.
  • Net Portal
    Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portal
  • Power Net Portal
    Wirelessly connects power nets on schematic. Identical to the net portal, but with a power symbol. Used to organize schematics and separate functional blocks. To wirelessly connect power net portals, give them the same designator. #portal #power
  • Generic Resistor
    A generic fixed resistor ideal for rapid circuit topology development. Its footprint automatically adapts based on the selected package case code—supporting 0402, 0603, 0805, 1203, and many other standard SMD packages, as well as axial horizontal and vertical configurations. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard resistor values: 1.0 ohm, 10 ohm, 100 ohm, 1.0k ohm, 10k ohm, 100k ohm, 1.0M ohm 1.1 ohm, 11 ohm, 110 ohm, 1.1k ohm, 11k ohm, 110k ohm, 1.1M ohm 1.2 ohm, 12 ohm, 120 ohm, 1.2k ohm, 12k ohm, 120k ohm, 1.2M ohm 1.3 ohm, 13 ohm, 130 ohm, 1.3k ohm, 13k ohm, 130k ohm, 1.3M ohm 1.5 ohm, 15 ohm, 150 ohm, 1.5k ohm, 15k ohm, 150k ohm, 1.5M ohm 1.6 ohm, 16 ohm, 160 ohm, 1.6k ohm, 16k ohm, 160k ohm, 1.6M ohm 1.8 ohm, 18 ohm, 180 ohm, 1.8K ohm, 18k ohm, 180k ohm, 1.8M ohm 2.0 ohm, 20 ohm, 200 ohm, 2.0k ohm, 20k ohm, 200k ohm, 2.0M ohm 2.2 ohm, 22 ohm, 220 ohm, 2.2k ohm, 22k ohm, 220k ohm, 2.2M ohm 2.4 ohm, 24 ohm, 240 ohm, 2.4k ohm, 24k ohm, 240k ohm, 2.4M ohm 2.7 ohm, 27 ohm, 270 ohm, 2.7k ohm, 27k ohm, 270k ohm, 2.7M ohm 3.0 ohm, 30 ohm, 300 ohm, 3.0K ohm, 30K ohm, 300K ohm, 3.0M ohm 3.3 ohm, 33 ohm, 330 ohm, 3.3k ohm, 33k ohm, 330k ohm, 3.3M ohm 3.6 ohm, 36 ohm, 360 ohm, 3.6k ohm, 36k ohm, 360k ohm, 3.6M ohm 3.9 ohm, 39 ohm, 390 ohm, 3.9k ohm, 39k ohm, 390k ohm, 3.9M ohm 4.3 ohm, 43 ohm, 430 ohm, 4.3k ohm, 43K ohm, 430K ohm, 4.3M ohm 4.7 ohm, 47 ohm, 470 ohm, 4.7k ohm, 47k ohm, 470k ohm, 4.7M ohm 5.1 ohm, 51 ohm, 510 ohm, 5.1k ohm, 51k ohm, 510k ohm, 5.1M ohm 5.6 ohm, 56 ohm, 560 ohm, 5.6k ohm, 56k ohm, 560k ohm, 5.6M ohm 6.2 ohm, 62 ohm, 620 ohm, 6.2k ohm, 62K ohm, 620K ohm, 6.2M ohm 6.8 ohm, 68 ohm, 680 ohm, 6.8k ohm, 68k ohm, 680k ohm, 6.8M ohm 7.5 ohm, 75 ohm, 750 ohm, 7.5k ohm, 75k ohm, 750k ohm, 7.5M ohm 8.2 ohm, 82 ohm, 820 ohm, 8.2k ohm, 82k ohm, 820k ohm, 8.2M ohm 9.1 ohm, 91 ohm, 910 ohm, 9.1k ohm, 91k ohm, 910k ohm, 9.1M ohm #generics #CommonPartsLibrary
  • Generic Capacitor
    A generic fixed capacitor ideal for rapid circuit topology development. You can choose between polarized and non-polarized types, its symbol and the footprint will automatically adapt based on your selection. Supported options include standard SMD sizes for ceramic capacitors (e.g., 0402, 0603, 0805), SMD sizes for aluminum electrolytic capacitors, and through-hole footprints for polarized capacitors. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard capacitor values: 1.0pF, 10pF, 100pF, 1000pF, 0.01uF, 0.1uF, 1.0uF, 10uF, 100uF, 1000uF, 10000uF 1.1pF, 11pF, 110pF, 1100pF 1.2pF, 12pF, 120pF, 1200pF 1.3pF, 13pF, 130pF, 1300pF 1.5pF, 15pF, 150pF, 1500pF, 0.015uF, 0.15uF, 1.5uF, 15uF, 150uF, 1500uF 1.6pF, 16pF, 160pF, 1600pF 1.8pF, 18pF, 180pF, 1800pF 2.0pF, 20pF, 200pF, 2000pF 2.2pF, 22pF, 220pF, 2200pF, 0.022uF, 0.22uF, 2.2uF, 22uF, 220uF, 2200uF 2.4pF, 24pF, 240pF, 2400pF 2.7pF, 27pF, 270pF, 2700pF 3.0pF, 30pF, 300pF, 3000pF 3.3pF, 33pF, 330pF, 3300pF, 0.033uF, 0.33uF, 3.3uF, 33uF, 330uF, 3300uF 3.6pF, 36pF, 360pF, 3600pF 3.9pF, 39pF, 390pF, 3900pF 4.3pF, 43pF, 430pF, 4300pF 4.7pF, 47pF, 470pF, 4700pF, 0.047uF, 0.47uF, 4.7uF, 47uF, 470uF, 4700uF 5.1pF, 51pF, 510pF, 5100pF 5.6pF, 56pF, 560pF, 5600pF 6.2pF, 62pF, 620pF, 6200pF 6.8pF, 68pF, 680pF, 6800pF, 0.068uF, 0.68uF, 6.8uF, 68uF, 680uF, 6800uF 7.5pF, 75pF, 750pF, 7500pF 8.2pF, 82pF, 820pF, 8200pF 9.1pF, 91pF, 910pF, 9100pF #generics #CommonPartsLibrary
  • Generic Inductor
    A generic fixed inductor suitable for rapid circuit topology development. The footprint automatically adapts based on the selected package, supporting standard SMD sizes (e.g., 0402, 0603, 0805) as well as well-known inductor packages such as SDR1806, PA4320, SRN6028, and SRR1260. Standard inductor values: 1.0 nH, 10 nH, 100 nH, 1.0 µH, 10 µH, 100 µH, 1.0 mH 1.2 nH, 12 nH, 120 nH, 1.2 µH, 12 µH, 120 µH, 1.2 mH 1.5 nH, 15 nH, 150 nH, 1.5 µH, 15 µH, 150 µH, 1.5 mH 1.8 nH, 18 nH, 180 nH, 1.8 µH, 18 µH, 180 µH, 1.8 mH 2.2 nH, 22 nH, 220 nH, 2.2 µH, 22 µH, 220 µH, 2.2 mH 2.7 nH, 27 nH, 270 nH, 2.7 µH, 27 µH, 270 µH, 2.7 mH 3.3 nH, 33 nH, 330 nH, 3.3 µH, 33 µH, 330 µH, 3.3 mH 3.9 nH, 39 nH, 390 nH, 3.9 µH, 39 µH, 390 µH, 3.9 mH 4.7 nH, 47 nH, 470 nH, 4.7 µH, 47 µH, 470 µH, 4.7 mH 5.6 nH, 56 nH, 560 nH, 5.6 µH, 56 µH, 560 µH, 5.6 mH 6.8 nH, 68 nH, 680 nH, 6.8 µH, 68 µH, 680 µH, 6.8 mH 8.2 nH, 82 nH, 820 nH, 8.2 µH, 82 µH, 820 µH, 8.2 mH #generics #CommonPartsLibrary
  • Terminal
    Terminal
    An electrical connector acting as reusable interface to a conductor and creating a point where external circuits can be connected.
  • RMCF0805JT47K0
    General Purpose Thick Film Standard Power and High-Power Chip Resistor 47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film Features: - RMCF – standard power ratings - RMCP – high power ratings - Nickel barrier terminations standard - Power derating from 100% at 70ºC to zero at +155ºC - RoHS compliant, REACH compliant, and halogen free - AEC-Q200 compliant
  • 875105359001
    10 µF 16 V Aluminum - Polymer Capacitors Radial, Can - SMD 30mOhm 2000 Hrs @ 105°C #commonpartslibrary #capacitor #aluminumpolymer #radialcan
  • CTL1206FYW1T
    Yellow 595nm LED Indication - Discrete 1.7V 1206 (3216 Metric)

Particular Blue KITT

Particular Blue KITT thumbnail
Integration of 2.9" Raw E-Paper Display with Raspberry Pi using FPC and Dedicated PMIC Driver

Properties

Maintain 40–60 mm spacing between the two microphones for optimal beamforming.

graph LR Pi[Pi Zero 2 W 40-pin header] MIC_L[Left PDM MEMS Microphone] MIC_R[Right PDM MEMS Microphone] EInk[2.9" E-Ink Display] NFC[NFC Tag IC] EEPROM[HAT ID EEPROM] Batt[AA Battery Pack] Boost[5V Boost Converter] SW_R[Reed Switch] SW_T1[Tactile Switch 1] SW_T2[Tactile Switch 2] Ant[13.56 MHz PCB Loop Antenna] Pi -- MOSI --> EInk Pi -- MISO --> EInk Pi -- SCK --> EInk Pi -- CS --> EInk Pi -- DC --> EInk Pi -- RST --> EInk Pi -- BUSY --> EInk Pi -- PDM_CLK --> MIC_L Pi -- PDM_CLK --> MIC_R Pi -- PDM_DAT --> MIC_L Pi -- PDM_DAT --> MIC_R Pi -- SDA --> NFC Pi -- SCL --> NFC Pi -- SDA --> EEPROM Pi -- SCL --> EEPROM Batt --> Boost --> Pi Pi -- GND --> GND Pi -- GPIO_R --> SW_R Pi -- GPIO_T1 --> SW_T1 Pi -- GPIO_T2 --> SW_T2 NFC -. Antenna .-> Ant

[{"type":"erc_missing_power_pin_connection","data":{"designator":"U2","pin":7,"description":"Unconnected power pin (U2, pin 7: VDD_A)"}},{"type":"erc_missing_power_pin_connection","data":{"designator":"U2","pin":8,"description":"Unconnected power pin (U2, pin 8: VDD)"}},{"type":"erc_missing_power_pin_connection","data":{"designator":"U2","pin":9,"description":"Unconnected power pin (U2, pin 9: VDD_RF)"}},{"type":"erc_missing_power_pin_connection","data":{"designator":"U2","pin":10,"description":"Unconnected power pin (U2, pin 10: VDD_TX)"}},{"type":"erc_missing_power_pin_connection","data":{"designator":"U2","pin":11,"description":"Unconnected power pin (U2, pin 11: VDD_AM)"}},{"type":"erc_missing_power_pin_connection","data":{"designator":"U2","pin":14,"description":"Unconnected power pin (U2, pin 14: VDD_DR)"}}]

Pin 1 (Gx) nearest PCB edge, orientation per panel datasheet

Maintain 5 mm clearance around VGH, VGL, and VCOM nets

mm

40–60

mm

Pricing & Availability

Distributor

Qty 1

Arrow

$10.10–$13.18

Digi-Key

$12.56–$15.54

LCSC

$37.89–$38.00

Mouser

$26.26–$26.32

TME

$0.07

Verical

$11.31–$17.75

Controls