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DSM-055 Bluetooth Cloud Module

Table of Contents

1. Product overview

DSM-055 are 2.4 GHz wireless SOCs optimized for line-powered Bluetooth Low Energy and Bluetooth mesh applications, including connected lighting, smart plugs, gateways and voice
assistants. An 80 MHz ARM® Cortex®M33 (EFR32BG21A010F768IM32-B) core provides plenty of processing capability while an integrated security subsystem provides leading security features that greatly reduce the risk of IoT security breaches and compromised intellectual property.  With better than -104dBm sensitivity and up to +19 dBm output power.

The module can support plug-in and patch mode, the production process is simple and convenient, the transmission power is large, and the receiving sensitivity is high, and it can be widely used in the field of smart home.

2. Features

  • ARM Cortex-M33, Floating-Point Unit
  • Up to 80 MHz Clock Speed
  • Up to 1024 KB of Programmable Flash
  • Up to 96 KB SRAM
  • BLE RF features
    Compatible with Bluetooth 5.0 and Bluetooth mesh specification
    Excellent receive sensitivity:
    -101dBm @125 kbps GFSK
    Programmable output power: Up to +19dBm
    Active mode RX:8.8mA
    Active mode TX:[email protected]
    Active mode TX: 33.8 [email protected]
    Antenna: PCB or IPEX
  • Support master mode, slave mode, broadcast mode (Beacon),
  • Support master-slave integration, connecting up to 8 slave devices
  • Support multi-master and multi-slave, can connect 3 masters and 4 slaves
  • Support SIG mesh, support multiple node types of mesh
  • Built-in onboard PCB antenna/reserved IPEX connector for high gain external antenna
  • Working temperature: -30℃ to +105℃
  • Humidly:<85%RH(No condensation)

3. Applications

  • Intelligent building
  • Smart household and home appliances
  • Smart socket and light
  • Industrial wireless control
  • Baby monitor
  • Network camera
  • Intelligent bus

4. Module interfaces

4.1 Dimensions and package

DSM-055 dimensions are 14.5 (±0.35) mm (W)×20 (±0.35) mm (L) ×2.8(±0.15) mm(H):

DSM 055 1
DSM 055 2
4.2 Pin definition
DSM 055 3
The definition of interface pins is shown in the following table:
Pin No. Symbol I/O
1 GND P Power supply reference ground pin
2 UART_TX PA05 MP test points need to be reserved for calibration
3 UART_RX P PA06 MP test points need to be reserved for calibration
4 SWDIO PA02 GPIO interface; 8mA drive capability. Wake-up function. Internal strong/weak
pull-up and pull-down. SWDIO (default)
6 ADC2 PB02 GPIO interface, which can be configured as an ADC
7 LOG PB01 Power-on mode: normal operation pull-down, bypassing the program code executed
in the flash (the PAD internal pull-down by default).
8 LED1 PB00 Common GPIO interface
9 SPI_CLK PC02 Common GPIO interface
10 SPI_MISO PC01 Common GPIO interface
11 SPI_MOSI PC00 Common GPIO interface
12 SPI_CSN PC03 Common GPIO interface
13 GND GND Power supply reference ground pin
14 RESET RESET MP test points need to be reserved for calibration
15 VCC VCC 1. Power:2V ~ 3.6V
2. MP test points need to be reserved for calibration
16 GND P Power supply reference ground pin
17 PWM1 PD04 Support PWM function LED (fixed timer), default connection cold LED
18 PWM2 PD03 Support PWM function LED (fixed timer), default connection warm LED
19 PWM3 PD02 1. The I2C SDA
2. LED support PWM such as breathing light (adjustable timer)
3. Red LED by default
20 PWM4 PC04 1. The I2C SCL
2. LED support PWM such as breathing light (adjustable timer)
3. Green LED by default
21 PWM5 PC05 1. LED support PWM such as breathing light (adjustable timer)
2. Blue LED by default
22 ADC1 PD00 Common GPIO interface
23 GPIO1 PA03 Common GPIO interface
24 GPIO2 PA04 Common GPIO interface

Note: P indicates a power supply pin, I/O indicates an input/output pin and AI indicates
an analog input pin. If you have your requirements on the light color controlled by PWM output,
please contact the business representative of Dusun.

5. Electrical parameters

5.1 Absolute electrical parameters
Parameter Description Minimum value Maximum value Unit
Ts Storage temperature –30 125
VCC Power supply voltage –0.3 3.8 V
Static electricity
discharge voltage (human
body model)
TAMB-25℃ - 2 KV
Static electricity
discharge voltage (machine
TAMB-25℃ - 1 KV
5.2 Working conditions
Parameter Description Minimum value Typical value Maximum value Unit
Ta Working temperature –30 - 105
VCC Working voltage 1.75 3.3 3.8 V
VIL I/O low level input –0.3 - VCC*0.3 V
VIH I/O high level input VCC*0.7 - - VCC V
VOL I/O low level output VSS - 0.3 V
VOH I/O high level output VCC–0.3 - VCC V
5.3 Power consumption in working mode
Symbol Conditions Typical value Unit
Itx Constantly transmit, output power of 0 dBm 10.5 mA
Irx Constantly receive 9.4 mA

6. RF features

6.1 RF output power

Unless otherwise indicated, typical conditions are: TA = 25℃, VCC = 3.0V, RF center
frequency 2.45 GHz.

Parameter Minimum value Typical value Maximum value Unit
Average RF output power –20 0 20 dBm
6.2 RF receiving sensitivity

Unless otherwise indicated, typical conditions are: TA = 25℃, VCC = 3.0V, RF center
frequency 2.45 GHz.

Parameter Minimum value Typical value Maximum value Unit
RX sensitivity 1 Mbps –95 –97 dBm
RX sensitivity 2 Mbps –93 –94 dBm

7. Antenna

7.1 Antenna type

DSM-055 uses an onboard PCB antenna or IPEX antenna.

7.2 Antenna interference reduction

To ensure the optimal RF performance, it is recommended that the antenna be at least
15 mm away from other metal parts.
Because DSM-055 is mounted to the main control panel through SMT, the placement location
and manner of the PCB directly affect the RF performance. The following are placement
positions recommended and not recommended.
Among them, placement positions in Solution 1 and 2 are recommended, that is, the antenna
is placed outside the frame of the panel, or the antenna is placed along the frame edge
of the panel with a carved area below. In the above two solutions, the RF performance is
not different from that of an independent module.
If the PCB antenna must be placed on the panel due to the design limit, you can refer
to the placement manner in Solution 3. That is, the antenna is placed along with the frame
of the panel without copper or traces below. However, the RF performance is still reduced
by 1 to 2 dBm.
The placement position in Solution 4 is not recommended. In this solution, the antenna
is placed on the PCB without a clearance area below, which greatly affects the strength
of the RF signal.

DSM 055 4
DSM 055 5

8. Production Instructions

Use an SMT placement machine to mount components to the stamp hole module that Dusun produces
within 24 hours after the module is unpacked and the firmware is burned. If not, vacuum pack
the module again. Bake the module before mounting components to the module.

  • SMT placement equipment:
    Reflow soldering machine
    Automated optical inspection (AOI) equipment
    Nozzle with a 6 mm to 8 mm diameter
  • Baking equipment:
    Cabinet oven
    Anti-static heat-resistant trays
    Anti-static heat-resistant gloves
  • Storage conditions for a delivered module are as follows:
    The moisture-proof bag is placed in an environment where the temperature is below 30°C
    and the relative humidity is lower than 70%.
    The shelf life of a dry-packaged product is six months from the date when the product
    is packaged and sealed.
    The package contains a humidity indicator card (HIC).
DSM 055 6
  • Bake a module based on HIC status as follows when you unpack the module package:
    If the 30%, 40%, and 50% circles are blue, bake the module for 2 consecutive hours.
    If the 30% circle is pink, bake the module for 4 consecutive hours.
    If the 30% and 40% circles are pink, bake the module for 6 consecutive hours.
    If the 30%, 40%, and 50% circles are pink, bake the module for 12 consecutive hours.
  • Baking settings:
    Baking temperature: 125±5℃
    Alarm temperature: 130℃
    SMT placement ready temperature after natural cooling:<36℃
    Number of drying times: 1
    Rebaking condition: The module is not soldered within 12 hours after baking.
  • Do not use SMT to process modules that have been unpacked for more than 3 months, because
    electroless nickel/immersion gold (ENIG) is used for PCBs and they are seriously
    oxidized for over 3 months. SMT is very likely to cause pseudo and missing soldering.
    Dusun is not liable for such problems and consequences.
  • Before using SMT, take electrostatic discharge (ESD) protective measures.
  • To reduce the reflow defect rate, draw 10% of the products for visual inspection and
    AOI before the first mounting, to determine the rationality of oven temperature control
    and component attachment and placement manners. Draw 5 to 10 modules from subsequent
    batches each hour for visual inspection and AOI.

9. Recommended oven temperature curve

Perform SMT based on the following reflow oven temperature curve. The highest temperature
is 245℃. The reflow oven temperature curve is as below:
Refer to IPC/JEDEC standard; Peak Temperature:<245℃; Number of Times: ≤2 times

DSM 055 7

10. Recommended oven temperature curve and temperature

For oven temperature setting, refer to oven temperatures for wave soldering. The peak
temperature is 260℃±5℃. The wave soldering temperature curve is shown below:

DSM 055 8

Recommended soldering temperature:

Recommended wave soldering
oven temperature
Recommended manual soldering
Preheat temperature 80 to 130℃ Soldering temperature 360±2℃
Preheat time 75 to 100s Soldering time <3s/point
Peak contact time 3 to 5s NA NA
Temperature of tin cylinder 260±5℃ NA NA
Ramp-up slope ≤2℃/s NA NA
Ramp-down slope ≤6℃/s NA NA

11. Storage conditions

DSM 055 9

12. MOQ and packaging information

Product No. MOQ (pcs) Shipping packaging
Number of modules
per reel (pcs)
Number of reels per
carton (reel)
DSM-055 4000 Tape reel 1000 4

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