BTM441 & BTM443 Series Bluetooth Module
Overview
The BTM44x series Bluetooth modules from Laird Connectivity have been designed to meet the needs of developers who wish to add robust, short-range Bluetooth data connectivity to their products. They are based on the market-leading Cambridge Silicon Radio BC04 chipset, providing exceptionally low power consumption with outstanding range. These modules support the latest Bluetooth Version 2.1 Specification, providing the important advantage of Secure Simple Pairing, which improves security and enhances the ease of use for end customers. In addition to Serial Port Profile, the BTM44x series features a number of additional features and profiles not found on other Bluetooth modules. Available in BTM440, BTM441, BTM442, and BTM443 variants.
Specifications
+4 dBm (from integrated antenna BTM441/443)
| Antenna Connector Type | Chipset (Wireless) | Connector Type | Dimension (Height - mm) | Dimension (Length - mm) | Dimension (Width - mm) | Frequency Range (Max) | Frequency Range (Min) | Input Power | Logical Interfaces | Max Transmit Power | Power Consumption | Protocols | Receive Sensitivity | Wi-Fi Coexistence | Wireless Specification | Software | Bluetooth Version | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| BTM441 | Integrated Antenna | CSR BC04 | SMT | 3.4 mm | 22 mm | 12.5 mm | 2.480 GHz | 2.402 GHz | 3.0 – 3.3V | UART | +4 dBm | < 40mA | AT Command Set | -84 dBm | 2 wire and 3 wire schemes supported | Bluetooth v2.1 + EDR | Terminal Software | v2.1 + EDR |
| Antenna Connector Type | Bluetooth Version | Chipset (Wireless) | Connector Type | Dimension (Height - mm) | Dimension (Length - mm) | Dimension (Width - mm) | Frequency Range (Max) | Frequency Range (Min) | Input Power | Logical Interfaces | Max Transmit Power | Power Consumption | Protocols | Receive Sensitivity | Software | Wi-Fi Coexistence | Wireless Specification | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| BTM443 | Integrated Antenna | v2.1 + EDR | CSR BC04 | SMT | 3.4 mm | 22 mm | 12.5 mm | 2.480 GHz | 2.402 GHz | 3.0 – 3.3V | UART | +4 dBm | < 40mA | Multipoint Mode | -84 dBm | Terminal Software | 2 wire and 3 wire schemes supported | Bluetooth v2.1 + EDR |
| Antenna Connector Type | Bluetooth Version | Chipset (Wireless) | Connector Type | Frequency Range (Max) | Frequency Range (Min) | Logical Interfaces | Max Transmit Power | Protocols | Receive Sensitivity | Software | Wi-Fi Coexistence | Wireless Specification | Input Power | Power Consumption | Dimension (Height - mm) | Dimension (Length - mm) | Dimension (Width - mm) | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| DVK-BTM443 | Integrated Antenna | v2.1 + EDR | CSR BC04 | USB Pluggable | 2.480 GHz | 2.402 GHz | UART | +4 dBm | Multipoint Mode | -84 dBm | Terminal Software | 2 wire and 3 wire schemes supported | Bluetooth v2.1 + EDR | 3.0 – 3.3V | < 40mA | 3.4 mm | 22 mm | 12.5 mm |
| Antenna Connector Type | Bluetooth Version | Chipset (Wireless) | Connector Type | Dimension (Height - mm) | Dimension (Length - mm) | Dimension (Width - mm) | Frequency Range (Max) | Frequency Range (Min) | Input Power | Logical Interfaces | Max Transmit Power | Power Consumption | Protocols | Receive Sensitivity | Software | Wi-Fi Coexistence | Wireless Specification | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| DVK-BTM441 | Integrated Antenna | v2.1 + EDR | CSR BC04 | USB Pluggable | 3.4 mm | 22 mm | 12.5 mm | 2.480 GHz | 2.402 GHz | 3.0 – 3.3V | UART | +4 dBm | < 40mA | AT Command Set | -84 dBm | Terminal Software | 2 wire and 3 wire schemes supported | Bluetooth v2.1 + EDR |
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Documentation
BT 2.1 - SSP initiated by a BTM module
This article is designed to illustrate the process of Simple Secure Pairing (SSP) when initiated from a BTM module. Introduced in Bluetooth v2.1, SSP creates a bond in a very different way than the legacy PIN pairing many users are familiar with. This is demonstrated both for security level 2 (default) and security level 3.
Security Level = 2
Assumptions:
peer device is BT2.1 (supporting secure simple pairing)
security level of BTM device is
security level of peer device is
the pairing initiating device is aware of the peer device's Bluetooth Device Address
Note: Connections in Bluetooth v2.1 are always encrypted.
Figure 1: BTM vs BTM
Figure 2: BTM vs PC
Security Level = 3
Assumptions:
peer device is BT2.1 (supporting secure simple pairing)
at least one device with security level = 3 (MITM protection / authentication enabled)
the pairing initiating device is aware of the peer device's Bluetooth Device Address
Remarks:
Connections with BT2.1 are always encrypted
"MITM" = Man-In-The-Middle. "MITM protection" means "protection against a MITM attack".
MITM protection is equivalent with authentication
Figure 3: BTM vs BTM, security level 3
Figure 4: BTM vs PC, security level 3
What is the throughput of your bluetooth modules with the embedded AT command interface?
Our fully-embedded modules have a throughput of around 300-360 kbps. They have an on-board Bluetooth stack and do all of the Bluetooth processing themselves. Bluetooth 2.1 + EDR has a practical transfer rate of 2.1 Mbit/s, but this is not possible on a small embedded module that does not have a powerful PC-type processor.