Arduino Tiny RTC I2C Real Time Clock

This Arduino Tiny RTC I2C module incorporates the DS1307 I2C real time clock IC and the 24C32 32K I2C EEPROM storage. What's more, it has a DS18B20 temperature sensor on board. All of this in a tiny package of 25mm x 28mm x 8.4mm. It comes with a LIR2303 rechargeable lithium battery, and a charging circuit is included in the module. When the temperature sensor is off, the RTC module can run for 1 year on a single charge.

This module is used for applications such as datalogging, timing applications ex. turning on the sprinkers at 4pm in the evenings. Since the module is self powered the time data is maintained even if the Arduino is powered off, allowing for building low power systems which can run for a long span of time without change of batteries.

Specs of DS18B20 Temperature Sensor

• 3.0-5.5V input voltage
• Waterproof
• -55°C to+125°C temperature range
• ±0.5°C accuracy from -10°C to +85°C
• 1 Wire interface

Wiring the RTC to Arduino

The most useful pins are duplicated from P1 to P2. If needed, the pin "BAT" can be fed into an ADC pin for monitoring the battery voltage. The pin-outs are explained below. Connecting "VCC" to 5 V will trickle charge the onboard battery.

The I2C wires "SDA" and "SCL" are the data line and clock line, they should be connected to the corresponding pins depending on the Arduino board.

Example code is available here.

For more detail, please visit the Arduino Wire Library.

Schematics

The schematics of this RTC module can be downloaded here.

Module consists of 8 relays. Each relay is connected to a current  buffer so that you can connect them directly to a Microcontroller.

Using these relays you can easily control power appliances, the relay is rated for 230V 10Amps.

This can be easily interfaced with Arduinos.

The Module has 9 LED's, one for power and 8 for indicating relay signals.

This module comes with a ribbon cable for easy interfacing of the relays to the Micro.

Rating:  10A 250V AC

Input voltage: 5V DC

This is a low cost motor controller. Although it's not an Arduino Shield, it can be used with Arduino or any other microcontroller platforms. This module allows you to connect 2 DC motors and have total control of them from the arduino. It also can be used to control one 4-wire stepper motor. Due to its high current rating, it's perfect for a single channel heavy duty stepper motor controller.

It allows you to move each DC motor
- Clockwise
- AntiClockwise
- Stall
- Control motor speed

A 4-way stripped wire is included.

This motor controller uses a L298 H-bridge IC
deliveries output current up to 2 A each channel. The speed control is achieved through conventional PWM which can be obtained from Arduinos PWM output Pin 5, 6, 9 and 10.

Specs:
Peak Output Current (each Channel)
- Non Repetitive (t = 100 ms): 3 A
-Repetitive (80% on -20% off; ton = 10 ms): 2.5 A
-DC Operation: 2 A
Analog voltage input:  
Vcc input:
7 - 35 V with jumper J3 short circuit, which gets regulated to 5 V and it's available on the +5 V terminal.
5 - 35 V with jumper J3 open circuit, a seperate 5 V input is needed to the +5 V terminal.
Digital voltage input: VD = 5 V (7 V max), this is output 5 V when jumper J3 is short circuit, and input 5 V when J3 is open circuit.
Max power dissipation: 20 W

There is a voltage regulator that regulates the Vcc to 5 V for digital use.

For more detail, please see

• How to use L298 motor controller
• PWM speed control of DC motor

Bluetooth Module (Master):

This is the HC-06 Bluetooth module, master. It can talk to the HC-06 Bluetooth module, device.

Please note:

• HC-06 master can only connect to HC-06 device.
• The role of a HC-06 Bluetooth module master and a HC-06 Bluetooth device cannot be interchanged, its defifined in its firmware, which is proprietary.
• The name of the master module cannot be changed, and other commands are the same as the device module.

Once the master detects a slave module with the same paring code, it will establish the connection. and next time, even after power down, once the master module detect the same slave module, it will automatically connect to it even other slave modules are also nearby. The master module recognizes that specific slave module through it's MAC number. A master module that is mated with a slave module has a slow flashing LED. Once connection established, its LED stays on. To reset the MAC number, press the button on the master module, or give the 'key/wake' pin a logic high impulse. Once it's reset, and if there are more multiple slave modules in the vicinity with the same paring code, the master module will randomly pick one to connect, and will again, lock into that module until the reset button is pressed.

Bluetooth Module:

Fig 1: Bluetooth module

This HC-06 Bluetooth module is the most economical and easiest way to go wireless.

This module allows you to wirelessly extend your serial interface, Hence any program running on your Laptop feels its controlling a local serial port (which is over a wireless bluetooth link )

The 4 pins are +5V, GND, TXD, RXD. Supply voltage should be 3.3 - 6 V. Absolute maximum is 7 V.

Default pairing code: 1234

Default baudrate: 9600

HC-04 is almost identical to HC-06. The only difference is that HC-04 is for industry and HC-06 is for civil. Other than that, they are the same. Please refer this HC-04 Datasheet for more technical information.

The maximum baudrate can be configured to 1382400bps, but 115200bps is recommended for reliability purposes. The name and paring code can be re-configured by a USB to Serial converter, the steps for the configuration can be found here.

Below shows how the Bluetooth module is connected to the Arduino or other microcontroller device. The Bluetooth module also works in 3.3 V power supply

Fig 2: Bluetooth module wiring

Once the wires are connected, in the computer under the Bluetooth properties, select ‘Add a device’. The default device name of the Bluetooth module is ‘linvor’

Fig3: Detecting the Bluetooth module

Double click ‘linvor’ and select the ‘Hardware’ tab, you can see which COM port the module is connected. In this example, it is connected to COM 21.

Fig4: Finding the COM port associated with the bluetooth module

You may use any terminal programs, or the open source terminal program puTTY. Download it and double click on the putty.exe, select the ‘Serial’ radio button.

Fig 5: Connecting to the bluetooth module using Putty application

Then type in the COM port number that the Bluetooth device is connecting to. The default baud rate is 9600. Click ‘Open’. And here you go, a new session pops up and if the Bluetooth module’s LED changed from flashing to always on, then it indicates the connection is established.

Test the Bluetooth module : Loopback testing

First test of the bluetooth module is call the the loopback test

• Wiring the Bluetooth to get power from the Arduino

To wire up the Bluetooth, power up the Arduino board (with usb or other power source), connect the +5 V and GND to the Arduino, then short circuit the rx and tx pin. 

By doing this, you’ll receive exactly what you send.

• Bluetooth test from PC

In the Bluetooth device properties of your computer, add the Bluetooth device by selecting ‘add a device’.

The default device name is linvor, and default pairing code is 1234, default baud rate 9600.

The device doesn’t need any driver. Please ignore the ‘unknown device warning’ in the windows device manager.

In the Bluetooth connection property, you can found which COM port the Bluetooth module is connected to.

Note: Until now the LED on the Bluetooth module is still flashing. Launch puTTY, type in the correct COM port and start the session. Soon after the session started, the flashing should stop and the LED on the Bluetooth module should stay on, which indicates that the connection has been established. In default setting, puTTY doesn't echo what you type, and whatever you type in puTTY gets sent to the Bluetooth module. So if you can see what you type in the terminal (non-repeated), it means the Bluetooth received the character you typed and sent it back to puTTY.

For advance users who want to customize the settings of the Bluetooth module, see Bluetooth module configurations. However, you are encouraged to skip this and continue to step3 to get your wireless rover working first!

Bluetooth module is not visible to Android phones and Android tablets?
It is reported that Android has some issues with the Bluetooth Serial Port Protocol (SPP). Installing TerminalBT app allows a pairing / connect to the Bluetooth module. This link explains it in a bit more detail.

Slow response in Arduino IDE when Bluetooth is enabled

When the Bluetooth of a laptop is enabled, the Arduino IDE becomes painfully slow and it is unusable. This is due to the auto-scanning COM port feature of the IDE. This link explains how to resolve this problem.

Step3: Combine Bluetooth with Motor Shield