HM-10 Bluetooth Low Energy serial module pinout

The documented HM-10 carries a Bluetooth Low Energy serial bridge with local UART and GATT service settings.

Huamao HM-10 bare module

34 contacts Current package

Jinan Huamao · 26.9 × 13 mm module with 34 castellations.

Huamao HM-10 bare module pinout

Huamao HM-10 bare module

Component-side view with the antenna at the top. Pad 1 is at upper left. The numbering passes down the left side, across the bottom and up the right side. Scroll the map to reach all contacts.

Selected pin details

22 · GND

Return · Ground

Common return. Connect every GND contact.

Jinan Huamao HM Bluetooth module datasheet V539, §§ 6.1–6.4

Electrical limits · Link to this pin

All 34 pins

Pin	Signal	Direction	Function
1	UART_TX Output	Output	Module serial data output. Connect to the host RX input.
2	UART_RX Input	Input	Module serial data input. Use 3.3 V logic.
3	UART_CTS Input	Input	Active-low hardware flow-control input.
4	UART_RTS Output	Output	Active-low hardware flow-control output.
5	NC No connection	No connection	No application connection. Leave open.
6	NC No connection	No connection	No application connection. Leave open.
7	NC No connection	No connection	No application connection. Leave open.
8	NC No connection	No connection	No application connection. Leave open.
9	NC No connection	No connection	No application connection. Leave open.
10	NC No connection	No connection	No application connection. Leave open.
11	RESETB Input	Input	Hold low for more than 100 ms for a hardware reset.
12	VCC Supply	Supply	Connect to the regulated 3.3 V supply.
13	GND Return	Return	Common return. Connect every GND contact.
14	GND Return	Return	Common return. Connect every GND contact.
15	USB_D− Bidirectional	Bidirectional	Module USB data minus, according to the terminal table.
16	NC No connection	No connection	No application connection. Leave open.
17	NC No connection	No connection	No application connection. Leave open.
18	NC No connection	No connection	No application connection. Leave open.
19	NC No connection	No connection	No application connection. Leave open.
20	USB_D+ Bidirectional	Bidirectional	Module USB data plus, according to the terminal table.
21	GND Return	Return	Common return. Connect every GND contact.
22	GND Return	Return	Common return. Connect every GND contact.
23	PIO0 Input	Input	System key input for the documented firmware.
24	PIO1 Output	Output	System LED output for the documented firmware.
25	PIO2 Bidirectional	Bidirectional	Digital I/O with PWM capability.
26	PIO3 Bidirectional	Bidirectional	Digital I/O and ADC capability. Check the firmware command table before using the pad.
27	PIO4 Bidirectional	Bidirectional	Digital I/O and ADC capability. Check the firmware command table before using the pad.
28	PIO5 Bidirectional	Bidirectional	Digital I/O and ADC capability. Check the firmware command table before using the pad.
29	PIO6 Bidirectional	Bidirectional	Digital I/O and ADC capability. Check the firmware command table before using the pad.
30	PIO7 Bidirectional	Bidirectional	Digital I/O and ADC capability. Check the firmware command table before using the pad.
31	PIO8 Bidirectional	Bidirectional	Digital I/O and ADC capability. Check the firmware command table before using the pad.
32	PIO9 Bidirectional	Bidirectional	Digital I/O and ADC capability. Check the firmware command table before using the pad.
33	PIO10 Bidirectional	Bidirectional	Digital I/O and ADC capability. Check the firmware command table before using the pad.
34	PIO11 Bidirectional	Bidirectional	Digital I/O and ADC capability. Check the firmware command table before using the pad.

Signal assignments

3.3 V serial UART

Connect module TX to host RX and module RX to host TX. Use a shared return and a 3.3 V logic adapter.

BLE serial bridge

The documented transmit firmware uses service UUID FFE0 and characteristic FFE1 by default. Query the installed firmware before relying on configured values.

Electrical limits

Parameter	Limit	Conditions and source
Module supply3.3 V DC	3.3 V DC	The vendor lists a 50 mA supply specification. Jinan Huamao HM Bluetooth module datasheet V539, Product parameters

Models and documents

This 34-pad HM-10 follows the Huamao V539 datasheet. The contact table and commands apply to the documented Huamao module and transmit firmware.

Jinan Huamao HM-10: 34-pad module in the V539 pinout and land pattern.

Jinan Huamao HM Bluetooth module datasheet V539· Jinan Huamao manufacturer datasheet hosted by Manuals+. Hardware map and transmit firmware AT protocol.