arduino lcd display clock supplier

Sometimes it may be necessary to use a display while making a hardware project, but the size and the type of the display may vary according to the application. In a previous project, we used a 0.96″ I2C OLED display, and in this project we will have an I2C 20×4 character display.

This liquid crystal display has 4 lines, 20 character in each line and cannot be used to display graphics. The main feature of this display that it uses I2C interface, which means that you will need only two wires to connect with Arduino. At the back side of the screen there is a small PCB soldered in the display, this circuit is a serial LCD 20 x 4 module and it also has a small trimpot to adjust the contrast of the LCD.

Display’s backlight is blue and the text is white. It is fully compatible with Arduino and has 5V input voltage. Its I2C address could be 0x27 or 0x3F. You can get it for about $7 from Bangood store.

DS3231 is a low-cost, accurate I2C real-time clock (RTC), with an integrated temperature-compensated crystal oscillator (TCXO) and crystal. The device incorporates a battery input, so that if power is disconnected it maintains accurate time.

RTC maintains seconds, minutes, hours, day, date, month, and year information. Less than 31 days of the month, the end date will be automatically adjusted, including corrections for leap year. The clock operates in either the 24 hours or band / AM / PM indication of the 12-hour format. Provides two configurable alarm clock and a calendar can be set to a square wave output. Address and data are transferred serially through an I2C bidirectional bus.

First we need to download the library of the display, which includes all required functions to configure and write on the display. You can find it here.

Unzip the library and add it to the Arduino libraries folder, then run Arduino IDE and copy the following code. The first two lines are to include both of I2C and LCD libraries.

lcd.setCursor(3,0) will set the cursor of the LCD in the specified location, the first argument for the column and the second for the row starting form 0.

Here we will use a small breadboard to connect the RTC module and display with the Arduino’s I2C pins (A4 and A5). The SCL pins are connected with analog 5 pin and the SDA pins with analog 6 pin. The top rail of the breadboard used as I2C bus and the bottom one is power bus.

In addition to setup and loop function, we will create four other functions to organize the code. As the corners and vertical lines of the frame are special characters, we have to create them manually. So we will use a function to create them and another one to print them on the LCD.

Inside the loop function the time will be read from the real time clock module and the printed to the LCD using a custom function for each of time and date.

At first, we have to include the three libraries, I2C, LCD, and RTC and set the LCD address. Inside the setup function the display is initialized, then we will call createCustomCharacters() function and print them.

Each character can be 5-pixel long in width and 8-pixel in height. So to create a custom character we need to create a new byte. We need 5 characters, the vertical line and the four corners. The yellow pattern shows you how the character will be displayed on the LCD.

Inside createCustomCharacters() function, we called lcd.createChar(#, byte array) function. The LCD supports up to 8 custom characters numbered from 0 to 7. It will assign the index in the first argument to the character given by the byte array. To print this character we can use lcd.write(byte(#)) function.

This function is very simple, it uses lcd.setCursor(#,#) to move the cursor and lcd.print(“”) to print the given string. The function will print the top and bottom horizontal lines, then printing other custom characters.

As we discussed earlier, the loop function will get the current time and date every second and refresh them on the display. First we defined a time element “tm” which has current time data, then if the time is correct and the RTC module working fine the time and date will be printed.

PrintTime function uses three arguments, the column and line where it will print the time, and the time element. lcd.print(tm.Hour) will print the hour, then if the minutes and seconds are less than 10 we will add 0 to the left. And the same method is used to print the date.

Now everything is ready, upload the code to your Arduino and enjoy watching your new clock. You can find the full Arduino sketches and libraries in the attachment below.

In electronics world today, Arduino is an open-source hardware and software company, project and user community that designs and manufactures single-board microcontrollers and microcontroller kits for building digital devices. Arduino board designs use a variety of microprocessors and controllers. The boards are equipped with sets of digital and analog input/output (I/O) pins that may be interfaced to various expansion boards (‘shields’) or breadboards (for prototyping) and other circuits.

The boards feature serial communications interfaces, including Universal Serial Bus (USB) on some models, which are also used for loading programs. The microcontrollers can be programmed using the C and C++ programming languages, using a standard API which is also known as the “Arduino language”. In addition to using traditional compiler toolchains, the Arduino project provides an integrated development environment (IDE) and a command line tool developed in Go. It aims to provide a low-cost and easy way for hobbyist and professionals to create devices that interact with their environment using sensors and actuators. Common examples of such devices intended for beginner hobbyists include simple robots, thermostats and motion detectors.

In order to follow the market tread, Orient Display engineers have developed several Arduino TFT LCD displays and Arduino OLED displays which are favored by hobbyists and professionals.

Although Orient Display provides many standard small size OLED, TN and IPS Arduino TFT displays, custom made solutions are provided with larger size displays or even with capacitive touch panel.

This is true, but I"m more comfortable with software than hardware and I figured that the functionality could be a good use for my Arduino kit. I can see two ICs on the board, a TI MP1508 (the larger of the two) and a DKI MSM5562RS. I have had a quick search on those two just now, but cannot find any data sheets for them.

As I recall it, the fault was that the time display started racing, then slowing down, then racing again, which in turn led it to turn on the mains power output as soon as it reached an alarm time. There was nothing wrong with the actual display itself, just the information it was displaying.

Yes, that might be the way to go, at least for now while I get it working. I can always change it later on. I do like to be able to use it as a normal digital clock which means having a visible display. A 16x2 LCD is a cheap way to give it a go. The article I just read showed a reasonable-looking font, it"s not incredible but it"ll do if I can get the brightness to a suitable level.

· Operating voltage: 5V· Alphanumeric character set· 4 lines of 20 characters· Blue Backlight· Module size: 98 x 60 x12mm· Display size: 75 x 25mm· I2C 2-wire connection· Built-in Contrast Adjustment

The code uses a PIR movement detector to turn the LCD display on and off. This Library is able to decode the DCF77 signal even if it contains a massive amount of noise. The library also "auto tunes" the Arduino Quartz crystal in the rare event the DCF77 signal is lost (no backup RTC required). For this Library to work your Arduino must use a Quartz crystal as a timebase not a problem if you build your own Arduino as I have. If you are using an Arduino Uno a Quartz crystal can be added my modding the UNO board. See how to do it here Mod standard Uno

As this clock drives other slave clocks as well as the built in analogue display this row monitors the main decoded display and it detects a jump in the seconds backwards or forwards. These will be shown as fast or slow seconds on Row 2 along with the date and time they were detected. On initial power up there are no fast or slow pulses so Row 2 Slow Pulse will be "0" and the date and time indicates when the clock was first power up and synchronized. The Fast Pulse will also show "0" but the date and time will show as "Never" The only time you would expect to see a Slow or Fast pulse detected is if the DCF77 signal was removed for several days then reconnected or if a leap second is injected (fast pulse)

Row 4 Sig Match - Once locked into the DCF77 signal Udo Klein"s library can predict what the next signal pulse should be. The Signal Match displayed as a percentage shows the quality of the received signal. 100% being a perfect match to the predicted signal.

Row 4 also shows the tuned accuracy of the quartz crystal. Once the clock has run for a number of days the accuracy of the quartz crystal is tuned until it reaches a max accuracy of 1Hz.

The attained accuracy is displayed. This is fully dynamic so the quartz crystal is continually tuned no matter the temperature or age drift of the crystal. Remember this is not the accuracy of the clock but the accuracy of the quartz crystal if the DCF77 signal was to fail.

This is an Arduino based digital Clock to display real time on a 16x2 LCD using a DS1307RTC module. The date and time can be set via serial interface or push button switches.

Time library adds timekeeping functionality to Arduino with or without external timekeeping hardware. This library is often used together with TimeAlarms and DS1307RTC.

The LCD Keypad shield includes 6 momentary push buttons and a blue backlight LCD which can display two row of 16 characters. The buttons are connected to only one analog input (A0) in order to saving on input/output pins.

The DS1307 serial real-time clock (RTC) is a low- power, full binary-coded decimal (BCD) clock/calendar plus 56 bytes of NV SRAM. DS1307 works on I2C protocol which can interfaces to most microcontrollers.

Display units play an important role in establishing good communication between the human and machine worlds. And so they are a big part of embedded systems.

The 16×2 LCD Screen will have a total of 32 characters, 16 in the 1st line, and a further 16 in the 2nd line. In 16×2 LCD there are 16  pins overall if there are backlight, 14 pins if there is no backlight. In each character, there are 50 pixels.

LiquidCrystal.h is a type of header file. SetCursor is a function that is present in the LiquidCrystal.h header file. With the help of this function, we fix the coordinate in the LCD Display.

Lcd.begin(16,2), 16×2 means that the LCD has 2 lines, and can display 16 characters per line. Therefore, a 16×2 LCD screen can display up to 32 characters at once.

This is a very low-power LCD clock, based on an AVR128DA48, capable of running for over three years from a CR2032 button cell, or for ever from a solar cell:

Every minute it also briefly displays the temperature, using the AVR128DA48"s on-chip temperature sensor, and the battery voltage, by using the ADC to read its own supply voltage. There"s also an I2C connection so you can add an external sensor, for example to show the humidity in addition to the other readings.

Although liquid crystal displays (LCDs) are relatively old technology, they still offer several advantages over newer types of display, including low power, low cost, and readability.

I recently bought some Densitron LCD displays on eBay for a few pounds/dollars, and I"d been wanting to try building a low-power clock around them, to see just how low I could get the power consumption. The displays are a standard type, available with compatible pinouts from several manufacturers. They are called static (as opposed to multiplexed), which means that every segment comes to a separate pin on the edge connector. This makes 28 pins for the segments plus three decimal points, a colon, and a common pin, adding up to 33 pins altogether. The displays I"ve found usually have two common pins, and also typically have other special-purpose segments, such as a minus sign, in a 40-pin package.

The displays are usually clear, but when you apply a voltage of about 3.3V between a segment and the common line the segment turns black. The displays I"m using have a reflective backing; they are also available with a translucent backing so you can add a backlight behind them.

There"s one catch; you can"t use a DC voltage to turn on the segments, because this would cause electrolysis to occur which would slowly degrade the display. The solution is to use AC by switching the polarity across the segment at a low frequency; 32Hz is usually recommended. Fortunately this is easy to do in software

Most 40-pin, 33mm row spacing displays should be compatible with this board; here are some I"ve found. These all have 4 digits and 3 decimal points on pins 5 to 27, 29 to 32, and 34 to 37, and commons on 1 and 40, plus a few extra symbols as shown:

Because of the number of interconnections I didn"t fancy prototyping this project by hand, but went straight to designing a PCB in Eagle, and I sent it to PCBWay for manufacture. I tried to make the PCB as general purpose as possible. It caters for any of the displays in the above table; to select which of the extra symbols you want to display you need to fit an 0Ω resistor to the board to act as a link.

Alternatively, if you want to power the clock from a 3V solar cell there are holes to allow you to fit a supercapacitor in place of the coin cell; I used a PowerStor 0.47F 5V one

The PCB also includes a 4-pin JST PH socket, providing an I2C interface compatible with Adafruit"s STEMMA system or the Grove system. You can use this to connect a sensor to the board, for example to show the humidity as well as the time and temperature, or you could use it to make the board an I2C slave so it can be used as an I2C display for other projects.

There"s no multiplexing, so to display a segment pattern we just need to write the appropriate value from the segment array, Char[0] to Char[11], to the port corresponding to the digit. Ports D, C, and A provide eight I/O lines each, so these map in a logical way to the seven segments and decimal point in digits 0 to 2. There"s a slight complexity with digit 3 because Port B only has six I/O lines available, so the segment corresponding to bit 6 is provided by PF5. The colon or other symbol is controlled by PF4.

The clock uses the Real-Time Clock (RTC) peripheral controlled by a 32.768kHz crystal to keep accurate time. The code to set up the RTC is almost identical to my earlier projects Mega Tiny Time Watch [Updated] and Big Time. It is configured as a Periodic Interrupt Timer (PIT), generating a regular interrupt. In this project I"ve used a divisor of 512, which divides down the 32.768kHz crystal to give 64 interrupts a second.

The interrupt service routine first toggles all the I/O lines connected to the LCD segments, and the common connections. Every 32 calls, or every half second, it calculates the current time, and checks whether the buttons are pressed. If the MINS or HRS buttons are pressed it advances the time by a minute or an hour respectively. It then calls the routine DisplayTime() to update the time, or at the end of each minute it calls DisplayVoltage() to display the battery voltage for three seconds, followed by DisplayTemp() to display the temperature for three seconds:

DisplayTime() copies the digits representing the current time to the corresponding output ports, specified by Digit[0] to Digit[3]. It also flashes the colon:

Unlike earlier AVR microcontrollers, where you had to calibrate the temperature sensor, the AVR DA and DB series have been calibrated during manufacture and contain calibration parameters in ROM. The temperature display is therefore pretty accurate without any additional calibration.

The processor spends most of its time in power-down sleep mode, to save power, and is woken up by the 64Hz interrupt from the Real-Time Clock peripheral. I measured the average power consumption at 3.3V for four different clock frequencies:

Usually you"d expect the power consumption to increase with processor clock frequency, so at first sight these figures are puzzling. The explanation is that at higher clock frequencies the time taken to execute the interrupt service routine is shorter, allowing the processor to spend a higher proportion of the time asleep.

The 32.768kHz external crystal oscillator has a low-power mode, and selecting this reduced the average power consumption with a 24MHz clock from 9.5µA to 7.3µA. The AVR128DA48 datasheet doesn"t seem to mention any downside to choosing the low-power mode, so I used this setting.

A CR2032 coin cell has a typical capacity of 225 mAh, so with a consumption of 7.3µA the expected battery life of the clock is 225/0.0073/24/365 or about 3.5 years.

With a 0.47F supercapacitor you can expect a current of 0.47A for 1 second. This gives an expected life of 0.47/7.3x10‑6/60/60 or about 18 hours, which I confirmed by testing it. This should be sufficient to keep the clock running overnight with a suitable solar cell providing power during daylight.

Pressing the MINS button resets the seconds to zero; this is designed so you can set the clock to the precise second, such as from a radio timecode. To do this, set the minutes to the current minute, and at the timecode at the end of the minute step the minutes on by one.

The HRS button doesn"t affect the seconds and minutes timing; this is designed to allow you to switch between Standard Time and Daylight Saving Time without affecting the clock setting.

Make a UPDI programmer from an Arduino Uno, or other ATmega328P-based board, as described in Make UPDI Programmer, and set the Programmer option to "jtag2updi".