DS3231 Precision RTC FeatherWing - RTC Add-on For Feather Boards
Pinout
- 3.3V
Board power input for the RTC FeatherWing. Adafruit Learn states the bottom-row 3.3V pin is used to power the RTC and take load off the coin cell battery.
Type · PowerVoltage · 3.3V - GND
Ground reference for the RTC FeatherWing. Adafruit Learn states the bottom-row GND pin is used with 3.3V to power the RTC.
Type · GroundVoltage · 0V - SCL
I2C clock pin for talking to the DS3231 RTC; Adafruit Learn states it has a 10K pullup resistor to 3.3V.
Type · I2CVoltage · 3.3V pullup - SDA
I2C data pin for talking to the DS3231 RTC; Adafruit Learn states it has a 10K pullup resistor to 3.3V.
Type · I2CVoltage · 3.3V pullup - SQW
Optional square-wave or interrupt output. Adafruit Learn states SQW is open-drain and needs a pullup to read from a microcontroller pin.
Type · SignalVoltage · external/internal pullup required - RST
Reset/power-loss indication pin. Adafruit Learn states RST is open-drain with an internal 50K pullup, stays high while VIN is present, and goes low when VIN drops and the chip switches to battery backup.
Type · ControlVoltage · internal 50K pullup; high while VIN present
| Pin | Type | Function | Voltage |
|---|---|---|---|
| 3.3V | Power | Board power input for the RTC FeatherWing. Adafruit Learn states the bottom-row 3.3V pin is used to power the RTC and take load off the coin cell battery. | 3.3V |
| GND | Ground | Ground reference for the RTC FeatherWing. Adafruit Learn states the bottom-row GND pin is used with 3.3V to power the RTC. | 0V |
| SCL | I2C | I2C clock pin for talking to the DS3231 RTC; Adafruit Learn states it has a 10K pullup resistor to 3.3V. | 3.3V pullup |
| SDA | I2C | I2C data pin for talking to the DS3231 RTC; Adafruit Learn states it has a 10K pullup resistor to 3.3V. | 3.3V pullup |
| SQW | Signal | Optional square-wave or interrupt output. Adafruit Learn states SQW is open-drain and needs a pullup to read from a microcontroller pin. | external/internal pullup required |
| RST | Control | Reset/power-loss indication pin. Adafruit Learn states RST is open-drain with an internal 50K pullup, stays high while VIN is present, and goes low when VIN drops and the chip switches to battery backup. | internal 50K pullup; high while VIN present |
Pin details
6 connections- 3.3V
Board power input for the RTC FeatherWing. Adafruit Learn states the bottom-row 3.3V pin is used to power the RTC and take load off the coin cell battery.
PowerVoltage · 3.3V - GND
Ground reference for the RTC FeatherWing. Adafruit Learn states the bottom-row GND pin is used with 3.3V to power the RTC.
GroundVoltage · 0V - SCL
I2C clock pin for talking to the DS3231 RTC; Adafruit Learn states it has a 10K pullup resistor to 3.3V.
I2CVoltage · 3.3V pullup - SDA
I2C data pin for talking to the DS3231 RTC; Adafruit Learn states it has a 10K pullup resistor to 3.3V.
I2CVoltage · 3.3V pullup - SQW
Optional square-wave or interrupt output. Adafruit Learn states SQW is open-drain and needs a pullup to read from a microcontroller pin.
SignalVoltage · external/internal pullup required - RST
Reset/power-loss indication pin. Adafruit Learn states RST is open-drain with an internal 50K pullup, stays high while VIN is present, and goes low when VIN drops and the chip switches to battery backup.
ControlVoltage · internal 50K pullup; high while VIN present
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