Data Sheet
Table Of Contents
- 1. Feature List
- 2. Typical Applications
- 3. Design Guidelines
- 4. Pin-Out Description
- 5. Power Control
- 6. Interface
- 7. Antenna
- 8. Bluetooth® Software Stack
- 9. Host Interface
- 10. Connection Examples
- 11. Electrical Characteristics
- 12. RF Characteristics
- 13. Packaging Specifications
- 14. Soldering Recommendations
- 15. Tape and Reel Packaging
- 16. Certifications
- 17. Ordering Guide
- 18. Revision History
6. Interface
6.1 GPIO
BT122 contains several pins which can be configured to operate as general-purpose digital I/Os, analog inputs, or to be used in combi-
nation with various built-in functions. The module contains I
2
C and UART communication. Most of pins (except PA0 and PA1) are 5V
tolerant. All GPIO pins can drive current of up to ±50 mA. Any available GPIO signal can be assigned an interrupt function. However,
the module microcontroller has a limited number of interrupt channels available for GPIO. In short, MCU classified interrupts in key of
modulo 4. So, for pins with number 0-3 for each port are available only 4 interrupts, and for next pins in the same way.
6.2 UART
There is one UART port available on the BT122. By default, it is used for BGAPI
™
host interface, but with BGScript
™
it can be used as
an application UART. The UART supports all standard baud rates up to 3 Mbps. RTS/CTS handshake scheme is supported and recom-
mended for every application for reliable data transfer.
6.3 I
2
C
BT122 has one available I2C channel, which support each defined mode:
• Standard-up to 100kbps
• Fast-up to 400kbs
• Fast Plus-up to 1Mbps
6.4 ADC
BT122 contains a 3-channel 12-bit ADC with multiple external input sources as well as an internal battery measurement and tempera-
ture measurement possibility. ADC input voltage range is 0 to VDD.
6.5 Real-Time Clock
BT122 contains a real-time clock (RTC) with full calendar support and sub-second resolution. The RTC can be used for periodic or
specifically programmed wakeups. The RTC is clocked by an internal crystal oscillator which is always on as long as power is supplied
to the module.
6.6 Microcontroller Programming Interface
The preferred method of programming the BT122 is by using DFU through UART host interface. Some problem may occur if bootloader
is disabled by disabling the UART or if the bootloader is overwritten accidentally. Then the bootloader would need to be re-uploaded.
Bootloader can be re-uploaded using SWD interfaces and J-Link options in BGTool™. SWD interface should be connected in following
pin configuration:
• PF0 – SWDIO
• PF1 – SWCLK
• PF2 – SWO
• RESET – RST
BT122 Data Sheet
Interface
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