Yes, that's correct. Bluetooth signals, Wi-Fi signals, and other wireless signals operate in the 2.4GHz frequency range. Therefore, if there are numerous Bluetooth devices, Wi-Fi devices, or obstacles such as walls in the vicinity, the Bluetooth signal can be affected.

1)Software Adjustment: The Bluetooth transmission power can be adjusted through software. Increasing the transmission power results in a longer communication distance.

2)Hardware Adjustment:

a) Antenna Selection (Coarse Adjustment): There are different types of antennas available, such as PCB antennas, ceramic antennas, and external antennas. Generally, larger-sized and higher-priced antennas provide better signal performance.

b) Fine Adjustment: The impedance matching of the antenna circuit needs to be optimized for optimal performance.

No, it's not. The ideal distance for Bluetooth communication depends on your project or specific use case. For example, a proximity tracker is best suited for distances within 10 meters. If the Bluetooth distance is too far, it might take a distance of 100 meters for the tracker to trigger an alert on the phone, by which time the wallet could already be lost.

Bluetooth can be divided into two types: Bluetooth for high data transfer rates and Bluetooth for low data transfer rates.

1) Bluetooth for high data transfer rates is known as Classic Bluetooth or simply Bluetooth. It sacrifices power efficiency to achieve higher data throughput. Examples include Bluetooth headphones and Bluetooth speakers.

2)Bluetooth for low data transfer rates is known as Bluetooth Low Energy (BLE). It offers power efficiency advantages, consuming as low as microamperes (uA) of power. It is commonly used in simple control applications, such as Bluetooth lights, Bluetooth curtains, Bluetooth cars, and Bluetooth door locks.

Classic Bluetooth and BLE are not compatible with each other and cannot communicate directly since they are based on different protocols.

Sure. However, most of the BLE apps available in the market act as central devices, so you would need to install a BLE app that acts as a peripheral device to broadcast data.

1) For iPhones: You can use LightBlue, which supports both central and peripheral roles.

2) For Android phones: nRF Connect is a suitable option.

Host and slave is the concept of the underlying Bluetooth, the devices that initiate the connection are the hosts, and the devices that are connected are the slaves. For example, a cell phone (host) actively connects to a Bluetooth light (slave).

Client and server is the concept of the upper layer (GATT layer), the client often needs to get data from the server. Example: Mobile phone The phone (client) gets the light on and off of the Bluetooth light (server).

Generally, the host is the client and the slave is the server.

But there are some exceptions, for example, the Bluetooth watch (slave, client) and the cell phone (host, server), when the cell phone calls, the cell phone will actively "notify" the phone number.

The phone will actively "notify" the phone number to the watch.

The reason why we need to clarify the relationship between the four is that we need to make it clear during the development process that the host has the right to initiate the connection and the server has the right to use the notify function.

So don't be surprised why the host can use the notify function, because

The host is the server at this point.

Bluetooth communication is similar to making a phone call. Let's say you are talking to a friend on the phone, and you both speak with a 3-second gap between sentences. If there is no response for more than 30 seconds, the call will be disconnected.

Now, imagine if you suddenly leave for a minute to use the restroom while someone is calling you. The caller will inevitably hang up because your restroom break exceeds the time they are willing to wait.

Similarly, if your Bluetooth communication is disconnected, it means your event processing time has exceeded the "connection interval + timeout" duration. To resolve this, you either need to reduce the event processing time or increase the "connection interval + timeout" duration.

Whether it is BLE or other communication technologies, receiver sensitivity is a critical parameter that largely determines the range of a chip's transmission capability. In technical terms, receiver sensitivity refers to the minimum signal energy that a chip can demodulate. For example, if a manufacturer's BLE chip has a receiver sensitivity of -97dBm at 1M PHY, it means that the chip can still demodulate a signal when the received signal energy is as low as -97dBm. As we know, with increasing distance, the signal undergoes greater attenuation during propagation, resulting in a decrease in the received signal energy. The fact that BLE chips can demodulate signals even at very low energy levels indirectly indicates a longer communication range.