User Manual

XR‐21A W
IFI modu
le
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Copyright©2019  ShenzhenJiXinInteligenceCo.,LtdAllRightsReserved 
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4 PA23 EXT_DCDC_PUP ； WUPIO9(wake up IO) ； EINTA23 ；
defaultcannotbehigh 
5 PA0 TWI1_SCL；EINTA0
6 PA1 TWI1_SDA；EINTA1；
PA18;TWI0_SDA;IR_TX;IR_RX;EINTA18
7 PA22 U A RT 2 _ T X ；P W M 3 / E C T 3 ；S P I 1 _ C S 0 ；W U P I O 8 ；E I N T A 2 2 
8 VCC powersupply,2.7~5.5V；
9 GND ground
10 PA21 UART2_RX;PWM2/ECT2；SPI1_CLK；WUPIO7；EINTA21
11 PA20 UART2_CTS;TWI0_SDA;PWM1/ECT1;SPI1_MISO;
WUPIO6;EINTA20
12 PB3 SWD_TCK；JTAG_TDI；PWM7/ECT7；EINTB3;
downloadmode:pull-down,Runmode:do
nothandleorpull-up
13 PA19 UART2_RTS;TWI0_SCL;PWM0/ECT0;SPI1_MOSI;
WUPIO5;EINTA19
14 PA7 UART1_TX；TWI0_SDA；EINTA7；
PA17;WUPIO4;TWI0_SCL;IR_RX;32KOSCO;EINTA17
15 RX0 UART0_RX；JTAG_TCK；PWM5/ECT5；SWD_TCK；EINTB1
16 TX0 UART0_TX;JTAG_TMS；PWM4/ECT4；SWD_TMS；EINTB0