USB Real Time Clock For Raspberry Pi
There are products like Data Loggers, Digital clock, Attendance system, Digital camera, etc. that have become devices for daily usage in the modern-day world. Advanced technologies like these need the timestamp for which RTC is an adequate option. For beginners, RTC is the abbreviation of “Real-Time Clock” which is an electronic device that allows the user to measure the passage of time. We came up with the product “USB RTC” for Raspberry Pi, Windows, LINUX, MACOS, STM32, etc and with the help of our design partner “SB Components”, USB RTC came into existence. It will increase the efficiency of the users with its powerful components and compact size.
Significance of USB RTC
A lot of people do not have an understanding of the utilization of the RTC in their devices. RTC or Real-Time Clock is a device to maintain the time in your system, that does not sound like the most important work to do but here most of the people are wrong. Before the extensive usage of the internet, RTC modules were used in devices like computers, sensors, monitoring devices, Digital watches, etc. to make them work efficiently in real-time.
Benefits of USB RTC
Now the devices are connected with the internet or GPS from which it can get the information in real-time that make the RTC useless but think about the scenarios where a user does not have a constant internet connection. A lot of places do not have the luxury of the constant internet connection that we will explore in this article. 
Communication via MCP2221
MCP2221 is the key component of the USB RTC module that works as a USB 2.0 to I2C /UART Protocol Converter with GPIO. It supports full-speed USB (12 Mb/s) that makes the communication between the Host and USB RTC with high efficiency. It comes with the Human Interface Device(HID) for both the chip control and I2CTM that allows better control of the user on the system. MCP2221 has built with Four GPIO lines that are configurable for GPIO Operations which enables the users to make better technically advanced products. 
Features of MCP2221
- I2C/SMBus supported clock and data lines
- User-selectable via jumper cable for 3.3V or 5V level output (up to 500 mA)
- Four GPIO lines that are configurable for GPIO Operations
- Pins for Serial(UART) Communication
- Supports full-speed USB (12 Mb/s)
- 64-byte Transmit
- 64-byte Receive
- USB 2.0 Compliant
Features of DS3231
- Extremely accurate I2C real-time clock (RTC)
- Integrated temperature-compensated crystal oscillator (TCXO)
- Incorporates a battery input
- 16-pin, 300-mil SO package
- Automated Backup Power Supply
- Fast (400kHz) I2C Interface
Specifications
- Accuracy ±2ppm from 0°C to +40°C
- Accuracy ±3.5ppm from -40°C to +85°C
- Battery Backup Input for Continuous Timekeeping
- Operating Temperature Ranges Commercial: 0°C to +70°C Industrial: -40°C to +85°C ♦ Low-Power Consumption
- Real-Time Clock Counts Seconds, Minutes, Hours, Day, Date, Month, and Year with Leap Year Compensation Valid Up to 2100
- Two Time-of-Day Alarms
- Programmable Square-Wave Output
- Fast (400kHz) I2C Interface
- 3.3V Operation
- Digital Temp Sensor Output: ±3°C Accuracy
- Register for Aging Trim
- RST Output/Push Button Reset Debounce Input
- Underwriters Laboratories (UL®) Recognized
