robotics-university.com | Hello friends, if you want to control any things wirelessly via your smartphone (Android/iOS), there is one useful wireless communication technology which can be use. The wireless communication technology that I mean is Bluetooth. On today article, I will give an overview about one of Bluetooth module that has been available on the market, i.e. HC-05 (Bluetooth V2.0) module. In general, this module used by embedded systems developer or hobbist to make wireless application with apply Bluetooth V2.0 technology.
Figure 1. HC-05 (Bluetooth V2.0) module
HC-05 (Bluetooth V2.0) Module Introduction
Quote from the datasheet, there are mention that HC-05 module is an easy to use Bluetooth SPP (Serial Port Protocol) module, designed for transparent wireless serial connection setup. Serial port Bluetooth module is fully qualified Bluetooth V2.0+EDR (Enhanced Data Rate) 3 Mbps.
Modulation with complete 2.4 GHz radio transceiver and baseband. It uses CSR Bluecore 04-External single chip Bluetooth system with CMOS technology and with AFH (Adaptive Frequency Hopping Feature). It has the footprint as small as 12.7mm x 27mm. Hope it will simplify your overall design/development cycle.
- Typical -80dBm sensitivity
- Up to +4dBm RF transmit power
- Low Power 1.8V Operation ,1.8 to 3.6V I/O
- PIO control
- UART interface with programmable baud rate
- With integrated antenna
- With edge connector
- Default Baud rate: 38400, Data bits:8, Stop bit:1,Parity:No parity, Data control: has. Supported baud rate: 9600,19200,38400,57600,115200,230400,460800.
- Given a rising pulse in PIO0, device will be disconnected.
- Status instruction port PIO1: low-disconnected, high-connected.
- PIO10 and PIO11 can be connected to red and blue led separately. When master and slave are paired, red and blue led blinks 1time/2s in interval, while disconnected only blue led blinks 2times/s.
- Auto-connect to the last device on power as default.
- Permit pairing device to connect as default.
- Auto-pairing PINCODE:”0000” as default
- Auto-reconnect in 30 min when disconnected as a result of beyond the range of connection.
HC-05 (Bluetooth V2.0) Module Dimension
The dimension of HC-05 (Bluetooth V2.0) module hardware are shows as on the figure 2 below.
Figure 2. HC-05 (Bluetooth V2.0) module - dimension
HC-05 (Bluetooth V2.0) Module Pins Description
In order you can use this HC-05 (Bluetooth V2.0) module, you have to know the pins description, so you will get this Bluetooth module work as your expectation. See figure 3.
Figure 3. HC-05 (Bluetooth V2.0) module - pin description
From figure 3 above, we know that HC-05 (Bluetooth V2.0) module has 30 pins and also equipped with on board PCB antenna. Pin specific definitions are listed in the following table:
Table 1. HC-05 (Bluetooth V2.0) module - pin description
For the detail information about HC-05 (Bluetooth V2.0) module pin description, you can download and read its document support (User Manual) from the link which available on the “Source” section of this article.
In the using, HC-05 (Bluetooth V2.0) module placed on the top of an adapter, so the pins that used for interfacing become six pins only, i.e. TXD, RXD, GND, VCC, and two additional pins of the adapter, i.e. State and Key. See figure 4 for the detail.
Figure 4. HC-05 (Bluetooth V2.0) module pin description on the top of its adapter
HC-05 (Bluetooth V2.0) Module AT Commands
For the operation, the HC-05 (Bluetooth V2.0) module parameters have to set using AT command. AT commands are instructions used to control and configure a modem or bluetooth module functionalities. AT is the abbreviation of ATtention. Every command line starts with "AT" or "at". That's why that commands are called with AT commands. Below is the AT commands list to configure the function of HC-05 (Bluetooth V2.0) module.
Table 2. AT commands list for HC-05 (Bluetooth V2.0) module configuration
For the detail information about HC-05 (Bluetooth V2.0) module AT command, you can download and read its document support (Datasheet) from the link which available on the “Source” section of this article.