Bluetooth V4.0 HM-11 BLE Module
HM-11 Bluetooth 4.0 BLE module with UART serial interface operating in the 2.4 GHz ISM band. Used to add low-energy wireless connectivity to microcontroller projects via AT commands.
Pinout
- UART_RTSpin 1
UART RTS
Type · UARTVoltage · 3.3V LVTTL - UART_TXpin 2
UART transmit
Type · UARTVoltage · 3.3V LVTTL - UART_CTSpin 3
UART CTS
Type · UARTVoltage · 3.3V LVTTL - UART_RXpin 4
UART receive
Type · UARTVoltage · 3.3V LVTTL - NCpin 5
No connection
Type · Control - NCpin 6
No connection
Type · Control - NVpin 7
Reserved/not user pin per Seeed table
Type · Unknown - NVpin 8
Reserved/not user pin per Seeed table
Type · Unknown - VCCpin 9
Power supply
Type · PowerVoltage · 3.3V - NCpin 10
No connection
Type · Control - RESETBpin 11
Reset, active low at least 5ms
Type · UnknownVoltage · 3.3V logic - GNDpin 12
Ground
Type · GroundVoltage · 0V - PIO3pin 13
IO port, used for DHT11/DS18B20 in Seeed docs
Type · GPIOVoltage · 3.3V logic - PIO2pin 14
Digital input/output
Type · GPIOVoltage · 3.3V logic - PIO1pin 15
LED indicator IO
Type · GPIOVoltage · 3.3V logic - PIO0pin 16
Button pin
Type · GPIOVoltage · 3.3V logic
| Pin | Position | Type | Function | Voltage |
|---|---|---|---|---|
| UART_RTS | pin 1 | UART | UART RTS | 3.3V LVTTL |
| UART_TX | pin 2 | UART | UART transmit | 3.3V LVTTL |
| UART_CTS | pin 3 | UART | UART CTS | 3.3V LVTTL |
| UART_RX | pin 4 | UART | UART receive | 3.3V LVTTL |
| NC | pin 5 | Control | No connection | |
| NC | pin 6 | Control | No connection | |
| NV | pin 7 | Unknown | Reserved/not user pin per Seeed table | |
| NV | pin 8 | Unknown | Reserved/not user pin per Seeed table | |
| VCC | pin 9 | Power | Power supply | 3.3V |
| NC | pin 10 | Control | No connection | |
| RESETB | pin 11 | Unknown | Reset, active low at least 5ms | 3.3V logic |
| GND | pin 12 | Ground | Ground | 0V |
| PIO3 | pin 13 | GPIO | IO port, used for DHT11/DS18B20 in Seeed docs | 3.3V logic |
| PIO2 | pin 14 | GPIO | Digital input/output | 3.3V logic |
| PIO1 | pin 15 | GPIO | LED indicator IO | 3.3V logic |
| PIO0 | pin 16 | GPIO | Button pin | 3.3V logic |
Pin details
16 connections- UART_RTSpin 1
UART RTS
UARTVoltage · 3.3V LVTTL - UART_TXpin 2
UART transmit
UARTVoltage · 3.3V LVTTL - UART_CTSpin 3
UART CTS
UARTVoltage · 3.3V LVTTL - UART_RXpin 4
UART receive
UARTVoltage · 3.3V LVTTL - NCpin 5
No connection
Control - NCpin 6
No connection
Control - NVpin 7
Reserved/not user pin per Seeed table
Unknown - NVpin 8
Reserved/not user pin per Seeed table
Unknown - VCCpin 9
Power supply
PowerVoltage · 3.3V - NCpin 10
No connection
Control - RESETBpin 11
Reset, active low at least 5ms
UnknownVoltage · 3.3V logic - GNDpin 12
Ground
GroundVoltage · 0V - PIO3pin 13
IO port, used for DHT11/DS18B20 in Seeed docs
GPIOVoltage · 3.3V logic - PIO2pin 14
Digital input/output
GPIOVoltage · 3.3V logic - PIO1pin 15
LED indicator IO
GPIOVoltage · 3.3V logic - PIO0pin 16
Button pin
GPIOVoltage · 3.3V logic
Start wiring
UART · SPI · 3.3 V · 5 V · Breakout
Seeed describes MDBT50Q-1M and MDBT50Q-P1M as Bluetooth 5.0 / BLE modules based on Nordic nRF52840, with GPIO, SPI, UART, I2C, I2S, PWM, …
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