Fingerprint Sensor AS608 - A Beginner's Guide
One touch can replace keys. This project uses an optical fingerprint sensor to enroll users and then grant access with a quick scan.
read tutorial →
THIS IS THE LATEST VERSION 2.1
The ChronoDot RTC is an extremely accurate real time clock module, based on the DS3231 temperature compensated RTC (TCXO). It includes a CR1632 battery (not shown, but included in the product) which should last at least 8 years if the I2C interface is only used while the device has 5V power available. No external crystal or tuning capacitors are required.
The top side of the Chronodot now features a battery holder for 16mm 3V lithium coin cells. It should work fine for CR1620 - CR1632 batteries.
Click here for documentation and example code.
The DS3231 has an internal crystal and a switched bank of tuning capacitors. The temperature of the crystal is continously monitored, and the capacitors are adjusted to maintain a stable frequency. Other RTC solutions may drift minutes per month, especially in extreme temperature ranges...the ChronoDot will drift less than a minute per year. This makes the ChronoDot very well suited for time critical applications that cannot be regularly synchronized to an external clock.
The ChronoDot will plug into a standard solderless breadboard and also has mounting holes for chassis installation.
The I2C interface is very straightforward and virtually identical to the register addresses of the popular DS1337 and DS1307 RTCs, which means that existing code for the Arduino, Basic Stamp, Cubloc, and other controllers should work with no modification.This new version has a battery holder, no soldering required!
TECHNICAL DETAILS
Dimensions (without battery):
- Length: 30.4mm/1.2in diameter
- Height: 14.1mm/0.55in
- Weight: 4 g
- This board/chip uses I2C 7-bit address 0x68
netduino driver, netduino sample and Documentation! This sample exercises all the functions of the clock (same as the DS1307 driver and samples)
Also recommended is Paul Stoffergen's RTC example code (for all Arduino's and compatibles): https://github.com/PaulStoffregen/Time andhttp://www.pjrc.com/teensy/td_libs_DS1307RTC.html
Manila stock. Order before 16:00 PHT, ships today via J&T or LBC. Provincial: 1–3 working days.
Schools / class POs: we accept Purchase Orders for accredited schools and universities. contact us with your PO details.
Returns: 7-day inspection window for DOA units. Email proof of issue and we ship a replacement.
Customers also bought
Build with this board
Thumb Joystick - A Beginner's Guide
Wire a joystick to your Arduino, read X/Y, then print UP / DOWN / LEFT / RIGHT to the serial monitor.
read tutorial →Motor Drive (BTS7960 43A) - A Beginner's Guide
Bench-test a 43 A motor driver before wiring the full project. Catches weak power, mis-pinning, and dead boards before they cost you time.
read tutorial →Raspberry Pi Pico (RP2040) - A Beginner's Guide
Coming from UNO and the Pico won't show a COM port? Here's the BOOTSEL trick, the driver fix, and the first sketch that actually works.
read tutorial →Notes from the bench
Ask the community
Project Showcase — show what you built
Share what you built. Photos, BOM, what worked, what didn't.
view thread →How to ask a good question (and actually get answers)
Symptom + what you tried + clear photo = answers within hours.
view thread →ESP32 brownout when wiring a sensor — fixes that worked
Brownout reset when adding a sensor? Notes on supply decoupling and GPIO checks.
view thread →First Arduino — sketch upload error, what to try?
Upload failing on your first Uno? Driver, COM port, board match — checklist inside.
view thread →