WCH BLE2U User manual

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BLE/UART/USBTransceiverModule BLE2U
Manual
Version:1C
http://wch.cn
1. Overview
The BLE/UART/USBtransceivermodule(BLE2U)isdeveloped based on CH9143 toimplementdata
transmission between BLE,USBinterface and UART.The BLEsupports mastermode, slavemode and
master-slavemode. BLEcommunication and parameters can be configuredinslavemode andmaster-slave
mode, and BLE4.2 issupported. The UARTsupports ATcommand configuration and MODEMsignals.The
baud ratecan be upto1Mbps.Itcan implementonlinedebug ordatamonitorbetween computerUSB
interface, serialport and Bluetooth atthe same time.
USBandBLEvirtualserialport technology.Avirtualserialport driverisprovided on thecomputer,
shielding the underlying technicaldetailsofBLEand USB,withno secondarydevelopmentrequired. Itis
compatiblewithcommon serialport applicationsandserialdebugtools,easytoimplementtransmission
between 3 "serialports".
BLE2Uproductselection:
Part No. Apperance Features
BLE2U-A-ANT
BLE2U-A
Onboard antenna
Small size
Built-in 32Mcrystal.
BLE2U-C-ANT
BLE2U-C
Onboard antenna
All functionalpins
Built-in 32Mand 32Kcrystals.
Some application block diagramsofCH9143:
Figure 1 Block diagramofserialcommunication between CH9143USBand BLEslave orUARTdevice

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Figure 2 Block diagramofserialcommunication between BLEhostand USBhostorUARTdevice through
CH9143
Figure 3 Block diagramofserialcommunication between USBhoststhrough CH9143 in BLEmaster-slave
mode
2. Features
Data transmission between BLE, USB, and UART.
BLEsupports slave mode, mastermode and master-slave mode.
ProvidesPC-side USBand BLEvirtualserialport driver.
Compatible with existing serialport software and tools, with no secondarydevelopmentrequired.
Supports BLEhostconnection inWindows/Linux/Android/iOS andothersystems.
2 serialport drivermodes:Vendordrivermode and installation-free USB-CDC drivermode.
100mBLEtransmission distance.
Adjustable 8 positionsofBLETXpower.
Supports 3.3Vand 2.5Voperating voltages.
Supports BLEtransmission configuration and serialATcommand configuration.
Asynchronousserialport default baud rate is115200bps.
Serialport supports MODEMsignals:RTS,DTR,DCD,RI, DSRand CTS.
Serialport supports 5/6/7/8 data bitsand 1/2stop bits.
Serialport supports odd, even, no parity, space 0 and mark 1.
Full-speed USBdevice interface, compatible with USBV2.0.

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3. Packagesize and pinsofBLE2U-A
PinNo. PinName PinType Description
1 BLE_MODE I BLEmode selection, with built-in pull-up resistor
Lowlevel:Slavemode. High level: Master-slavemode.
2 VCC P Powerinput
3 GND P Ground
4 LED O Module statusand data receive/transmitindication
outputpin, active low
5 UD+ USBsignal USBD+ data line
6 UD- USBsignal USBD-data line
7 TXD O UARTtransmit pin
8 RXD IUARTreceive pin
Note:P:Power. I:Input. O:Output.
4. Recommended bondingpadsize forBLE2U-A
Symbol Value Unit
A 10.22
mm
B 10.6
C 1.02
D 0.8
E 1.27
F 0.74
G 1.7

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5. Packagesize and pinsofBLE2U-C
PinNo. PinName PinType Description
1 GND P Ground
2 PANT A Optionalpin to connectantenna externally(Note 2)
3 SWREG_EN I InternalDC-DC powerenable, with built-in pull-up resistor
Enabled when atlowlevel
4 BLE_MODE I Bluetooth mode selection, with built-in pull-up resistor
Lowlevel:Slavemode. High level: Master-slavemode.
5 RTS# O UARTMODEMoutputsignal, requestto send, active low
6 DCD# I UARTMODEMinputsignal, data carrierdetection
7 RI# I UARTMODEMinputsignal, ring indicator
8 CTS# I UARTMODEMinputsignal, clearto send, active low
9 NC N Suspended pin. Donotconnectto it.
10 NC N Suspended pin. Donotconnectto it.
11 GND P Ground
12 VCC P Powerinput
13 LED O Chip statusanddata receive/transmitindication outputpin, active
low
14 DSR# I UARTMODEMinputsignal, data device ready

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15 AT I ATtransparenttransmission function switch pin:
Lowlevel:ATmode. High level:Transparenttransmission mode
16 RELOAD
/BLESTA I/O
Restore factorysetting inputpin (RELOAD)when powered on,
Restore the factorysettingsaftera lowlevelisdetected for2
secondscontinuously.
BLEconnection statusindication signaloutputpin (BLESTA)
afterpowered on. Itoutputslowlevelwhen notconnected, while it
outputshigh levelwhen connected.
17 FCE I CTS/RTS flowcontrolenable, active low, with built-in pull-up
resistor
18 DTR# O UARTMODEMoutputsignal, data terminalready
19 UD+ USBsignal USBD+data line
20 UD- USBsignal USBD-data line
21 TXD O UARTtransmit pin
22 RXD I UARTreceive pin
23 RST# I Resetpin, active low
24 TNOW O UARTtransmit statuspin, active high
Note (1): P:Power.A:Analog. I:Input. O:Output. N:Noconnection.
Note (2): Touse an externalantenna, the usercan connectthe PANTpin to the antenna pin through the
reserved resistorpad. Re-solderthe resistorwhich connectsthe antenna pin toon-board antenna, to
connectthe antenna pin to thePANTpin.
6. Recommended bondingpadsize forBLE2U-C
7. Layout
The upperpart ofthe moduleisthe onboardantenna,and the layoutofantenna isrelated toqualityof
wireless communication. Good communication qualitycanensureastabledatatransmission rate. The
modulecan run separatelywithoutextraground plane, butwhen it isinstalled on the otherPCB,it shouldbe
noted:Antenna area mustbe farawayfromothermetalcomponents,and the distance mustbe greaterthan
20mm.Anyconductornearthe antennamayseriouslyaffectthe antenna radiation pattern.
Symbol Value Unit
A 18.02
mm
B 15.26
C 0.99
E 1.27
F 3.12
G 3.18
H 1.27
J 1.8
K 1

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The figurebelowshowsthe reference layoutofthe module. The first three casesarecorrect,aslong asthe
ground plane doesnotexceedthe ground plane edge ofthe module. The lastthree casesareincorrect.The
exampleon the left isincorrectbecausethereisaground plane underthe antenna,the middleexampleis
incorrectbecausethereisnotenough gap aroundthe antenna, and thelastexampleisincorrectbecause
batterymetalcasing isnotfarawayfromantenna area.
8. Functional description
8.1 Smartpairing
When theCH9143 isinmaster-slavemode, it can be paired withthe designatedCH914x withoutinputting
MACaddress throughATcommand. Aftersuccessfulpairing, the twowill establishabinding relationship,
and there isno need to re-pair when connecting again.
Pairing process isasfollows:
1)The CH9143 isin master-slavemode, and the CH9140/CH9143 isin slave mode ormaster-slavemode;
2)Both sidesneed to complete power-up within 3sto establish a pairing;
3)The indicatorLEDflashes3 timesand then keepson, indicating thatpairing issuccessful.
Ifthe userneedstore-establishthe pairing, repeatthepairing processagain.Thedifference isthatthe
indicatorLEDinstep 3will flashquickly.Inthiscase, thepairing can be re-established bypowering on one
side.
8.2 Data transmission
The CH9143 can implementdata transmission between UART,USBand BLE.The data received byanyone
interface will be transmitted to the other2 interfaces.
The serialport interface isanasynchronousUART. The default setting is115200bit/sbaud rate, 8data bits, 1
stop bit, no parityand enabled flowcontrol. BLEcommunication rate isrelated to itsenvironment, so it is

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recommended to useCTS/RTS flowcontrolto preventbufferoverflowwhen the baud rate exceeds9600bit/s
and the BLEaverage RSSIisless than -70dBm.The USBinterface isa USB2.0 full-speed device, which
communicateswith PCthrough analog serialport device, and iscompatible with common serialsoftware.
8.3 LEDfunction
ListofLEDstatusdescription
No. Status Description
1 once quicklyflashes3 timesafterpowered on currentlyin slave mode
2 twice quicklyflashes3 timesafterpowered on currentlyinmaster-slavemode
3 slowlyflashesat500msintervals currentlyin broadcaststatus
4 keepson currentlyin connection status
5 quicklyflashesin connectionstatus currentlyperforming data transmission
6 quicklyflashesin pairing process hasbeen paired with otherdevices, need
power-up again to complete pairing
Fordetails, please referto CH9143 datasheet.
9. Schematicdiagramforreference
3V3
GND
1K
R2 D1
LED0
3V3
RXD_CONNECT_MCU_TXD
TXD_CONNECT_MCU_RXD
GND
2
3
1 S1
Select 1for master-slave mode
Select 3for slave mode
GND
1
PANT
2
SWREG_EN
3
BLE_MODE
4
RTS#
5
DCD#
6
RI#
7
CTS#
8
NC
9
NC
10
GND
11
VCC
12
LED
13
DSR#
14
AT
15
RL/BSTA
16
FCE 17
DTR# 18
UD+ 19
UD- 20
TXD 21
RXD 22
RST# 23
TNOW 24
U1
BLE2U-C
GND
CONNECT_MCU_UD-
CONNECT_MCU_UD+

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10. Reflowsolderingconditions
Moisture SensitivityLevel MSL3
Average slope rise rate (TLto TP) Max 3℃/s
During warmup
Minimumtemperature (Tsmin) 150℃
Maximumtemperature (Tsmax) 200℃
Time (minimum –maximum) (ts) 60-180s
Tsmax –TLslope rise rate Max 3℃/s
During hold
Temperature (TL) 217℃
Time (tL) 60-150s
Peak temperature (Tp) 260+0/-5℃
Time when actualpeak temperature iswithin 5℃(tp) 20-40s
Slope descentrate Max 6℃/s
Time from25℃to peak temperature Max 8 min