The HM-10 is a Bluetooth 4.0 module that is based on the TI CC2530 or CC2541 Bluetooth SOC (System-on-Chip). The HM-10 is a very popular Bluetooth 4 module for the Arduino, mostly due to its cheap cost and ease of use. The HM-10 provides a standard serial connection to the Bluetooth layer. This allows for a very straightforward interface; however, it does hide the actual Bluetooth LE layer.
In Chapter 21, Bluetooth Classic, when we look at the HC-05 Bluetooth module, you will notice that the interface between the HC-05 and HM-10 use the same serial interface; however, understanding the difference between Bluetooth LE and Bluetooth Classic technologies will help you decide which to use in your project.
We can control the module using AT commands, and we will look at how to do that in the project section of this chapter. The following photograph shows what the HM-10 Bluetooth module looks like:
The HM-10 has six pins. However, we are only interested in the middle four, which are:
- VCC: Connected to the 3.3V power out on the Arduino
- GND: Connected to the ground on the Arduino
- TX: Transmit pin, connected to one of the digital pins on the Arduino
- RX: Receive pin, connected to one of the digital pins on the Arduino
Now let's look at all of the components that we will need for the projects that we will be doing in this chapter.