Raspberry Pi Audio HAT Design

flux

The schematic is wired and I created the spec, firmware starter, and bring-up plan documents; I’m moving on to 2-layer HAT board setup and placement.

flux

Implemented the Raspberry Pi smart audio translation HAT: schematic, GPIO/I2S wiring, 5V protection path, buttons, LEDs, decoupling, speaker isolation, test points, 65 × 56.5 mm 2-layer HAT outline, and initial component placement. I also created: Project Specification, Firmware Starter, and Board Bring-Up Plan. Estimated time saved vs. manual EDA workflow: ~8–12 hours.
Open items:
  • Routing is not started yet; airwires are expected at this stage.
  • Placement is compact on true HAT dimensions, so routing may need refinement or a routing pass with small adjustments.
  • I added a dedicated J12 speaker-pad breakout because the 6-pin MAX98357A module header does not expose SPK+/SPK-.
Suggested next steps:
  1. Review/approve the placement before routing.
  2. Route the board with wider 5V and speaker traces.
  3. Add/verify top and bottom GND copper fills after routing.
  4. Run final DRC/ERC cleanup and prepare manufacturing exports.
Route and verify
Route the PCB
Add ground pours
Fix DRC issues
Check BOM cost
R1 P2 - D1 A
J1 35 - J2 4
J1 29 - SW1 1
J1 1 - J1 17
J1 12 - J2 3
J1 35 - J2 4
J12 1 - J4 Pin_1
J1 4 - J3 1
J1 1 - J1 17
J1 1 - J1 17
F1 P2 - J1 2
R2 P2 - LED1 A
J1 33 - SW3 1
J12 2 - J4 Pin_2
J1 36 - R2 P1
J1 37 - SW4 1
J1 40 - J3 5
J1 4 - J3 1
J1 40 - J3 5
J1 35 - J2 4
J1 38 - J2 5
J1 31 - SW2 1
J1 1 - J1 17
J1 38 - J2 5
J1 12 - J2 3
J1 12 - J2 3
GND
J1 20 - J1 25
J1 34 - J1 39
J1 34 - J1 39
GND
GND
GND
GND
J1 20 - J1 25
J1 20 - J1 25
J1 34 - J1 39
J4
J3
D1
LED1
J1
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Raspberry Pi Smart Audio Translation HAT

Raspberry Pi Smart Audio Translation HAT thumbnail
2-layer Raspberry Pi 4 HAT for a smart audio translation system with I2S microphone, I2S amplifier, speaker terminal, buttons, LEDs, protected 5V input, and test points.

Properties

Audio

5

V

2-layer PCB

Raspberry Pi HAT

Buttons

Pricing & Availability

Distributor

Qty 1

Arrow

$7.26–$8.17

Digi-Key

$6.31

HQonline

$0.31

LCSC

$12.83–$12.84

Mouser

$9.67

TME

$0.56

Verical

$5.68–$13.65

Controls