Adafruit DS3231 Precision RTC - STEMMA QT POL_3pi+ 32U4 OLED Robot The I/O lines of both

The I/O lines of both the ATmega32U4 and the Raspberry Pi are broken out to 0

compass & sonar data  0x05 SCAN2 9 Same but for 2 SRF08's 0x06 SCAN3 12 3 SRF08's 0x07 SCAN4 15 4 0x08 SCAN6 21 6 0x09 SCAN8 27 8 0x0A SCAN12 39 12 0x0B SCAN16 51 All 16 possible SRF08's 0x10 SETPINS 1 Sets I/O pins high/low 0x11 GETPINS 1 Gets the status of I/O pins  0x12 GETAD 4 Gets Analogue value on I/O2 and I/O3

We generally recommend using a 4- or 5-cell NiMH or NiCD battery pack to power the switch

it connects directly to the designated cooling fan port on RoboClaw (V5D versions or later)

Adafruit DS3231 Precision RTC - STEMMA QT POL_3pi+ 32U4 OLED Robot The I/O lines of bothThe datasheet for the DS3231 explains that this part is an "Extremely Accurate IC Integrated RTC TCXO Crystal". And, hey, it does exactly what it says on the tin! This Real Time Clock (RTC) is the most precise you can get in a small, low power package. We've had a breakout board version of this RTC for a while , but we want to make it even easier for folks to use, so now it comes with STEMMA QT connectors for plug and play simplicity. Most RTCs use an