Chip Connection Instructions


Below is a summary of recommended schematic connections for each IC. These ensure proper power, ground, and I²C operation. You can use the “Apply changes” button to add and connect the missing components and nets in your schematic.

1. U2 (U2) EEPROM
  • Supply & Ground:
    • Wire VCC (pin 8) to +3V3 net.
    • Wire GND (pin 4) to Ground net.
  • Address & Write Protect:
    • Tie A2 (pin 3) to Ground for the standard address (0x50).
    • Tie WP (pin 7) to Ground to enable writes.
  • I²C Signals:
    • Connect SCL (pin 6) to RPi1 SCL/GPIO3.
    • Connect SDA (pin 5) to RPi1 SDA/GPIO2.

2. U3 (U3) 16-Bit DAC
  • Power & Ground:
    • Wire VDD (pin 1) to +3V3 net.
    • Wire GND (pin 8) to Ground net.
  • Reference & Output:
    • Connect VREF (pin 2) to +3.3V for full-scale range (or another reference if desired).
    • Tie V(SENSE) (pin 3) to the same net as VREF (pin 2) for proper sensing.
  • Address & I²C Signals:
    • Tie A0 (pin 5) to Ground for the default I²C address.
    • Connect SCL (pin 6) to RPi1 SCL/GPIO3.
    • Connect SDA (pin 7) to RPi1 SDA/GPIO2.

3. U5 (U5) RTC
  • Power & Ground:
    • Wire VDD (pin 8) to +3V3 net.
    • Wire VSS (pin 4) to Ground net.
  • Battery Backup (optional):
    • If no backup battery is used, connect VBAT (pin 3) to +3.3V. Otherwise, use a coin cell or backup supply as specified in the datasheet.
  • I²C Signals:
    • Connect SCL (pin 6) to RPi1 SCL/GPIO3.
    • Connect SDA (pin 5) to RPi1 SDA/GPIO2.
  • Oscillator Pins (optional 32.768kHz crystal):
    • Wire a 32.768kHz crystal between OSCI (pin 1) and OSCO (pin 2).
    • Add two small load capacitors (e.g., 12-15pF) from each crystal pin to Ground.

4. Pull-Up Resistors (if needed)
If you need external I²C pull-ups instead of relying on the Pi’s internal ones, add two resistors (e.g., 4.7kΩ or 10kΩ) from SCL and SDA to +3V3.

Use the "Apply changes" button to add and wire these components and nets in your schematic.
Connect all I²C chips
Wire U2 EEPROM
Implement I²C connections
Apply connection changes

Schematic of Raspberry Pi 5 Hat Template
U3
U5
H3
RPi1
H4
H2
+5V
H1
U2
+3V3

Raspberry Pi 5 Hat Template