STM32F429 422串口通信 1.422串口的硬件原理图如下:
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2.422串口和232串口不同的是引脚的电平控制,还有DE是发送使能,置高即可:RE是接收使能,置低即可。422接出来的是4根线,有RS485_A、RS485_B、RS485_Z、RS485_Y,对应422串口线的DB1、DB2、DB3、DB4,,DB5连接地线,其他的配置用232串口的代码即可。 ) f, _0 E/ A2 f8 \6 Y8 `
3.GPIO的配置: - void RS422_Config()5 m# a0 q4 W; e
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+ W/ F" `. ^4 U* v7 U, P - GPIO_InitTypeDef GPIO_InitStructure;
& `) c- Q8 ]* j, I/ x% }) q/ z( b - USART_InitTypeDef USART_InitStructure; H* K1 W N6 J
- /* PC6/USART6_TX , PC7/USART6_RX, PG12/USART6_RTS, PG13/USART6_CTS */; v/ K- \1 X( ~& n2 J: w0 }
* P. M: s a, @/ t- RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC |RCC_AHB1Periph_GPIOG, ENABLE);
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9 f6 H: T1 L3 f% D+ L4 t" F0 Y- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;3 \' e2 O, u! k! k* j. R: x4 S
- GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;2 Z. L7 X& G, x B. y. K" z7 @& }
- GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;2 y& I" F& i4 o: D' t4 N- n8 m
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
9 N4 j8 `: v& S. z. c' u - GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12 | GPIO_Pin_13;+ U# C. x0 g6 `7 d9 P5 ?) B
- GPIO_Init(GPIOG, &GPIO_InitStructure);9 N* M. T3 b I
3 V0 U; A; H8 r- GPIO_ResetBits(GPIOG,GPIO_Pin_12); //USART6_RTS
4 B6 [8 Y0 N8 u0 r3 R8 |/ _ - GPIO_SetBits(GPIOG,GPIO_Pin_13); //USART6_CTS5 X8 x e& U* o! q7 f
" n. g4 m: H9 c- RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART6, ENABLE);9 a- {9 }/ u z) t1 R
s' ~$ K& o2 |3 K( o8 y- GPIO_PinAFConfig(GPIOC, GPIO_PinSource6, GPIO_AF_USART6);+ t7 b& A/ f/ e3 a) e
8 B/ J9 b5 m8 @ X5 G- GPIO_PinAFConfig(GPIOC, GPIO_PinSource7, GPIO_AF_USART6);- N0 {# i) @$ E6 T8 f
+ w7 J V5 H& H# }- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;0 L0 p9 C2 L8 b* [. V2 X, O, _2 Z3 p" u
- GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
/ u$ t3 f2 a' X$ x5 H - GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
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{% v1 f1 y& I( z* O- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;) ]9 i# x$ b- w0 Q& |& b
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
' p0 E. E! u, [+ S {3 @# b) f' z9 c8 | - GPIO_Init(GPIOC, &GPIO_InitStructure);
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/ K( N1 f& M( U' A- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;/ M7 L+ y7 l- `
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;) i# L2 K+ q3 Z% ]
- GPIO_Init(GPIOC, &GPIO_InitStructure);0 M$ t: Y g# H1 T8 f- d
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- USART422_NVIC_Config();
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# f2 ^6 N* b* S0 Z) a. m6 ^$ G- USART_InitStructure.USART_BaudRate = 115200;+ _! |3 B' g6 d. z) a0 B% t4 P5 b& j
- USART_InitStructure.USART_WordLength = USART_WordLength_8b; b0 j# B# `) N9 F
- USART_InitStructure.USART_StopBits = USART_StopBits_1;9 X: K, C. H' n+ Q
- USART_InitStructure.USART_Parity = USART_Parity_No ;# ~5 e& ?4 G4 }. s4 t4 E. y5 g
- //USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_RTS_CTS;! ~: c- b; b4 ?/ a! @) C& P, `) E+ L
- USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;9 _: B1 h/ ~6 @! n; j
- USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
% B& \8 i, A K1 {# B5 x& v - USART_Init(USART6, &USART_InitStructure);
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- USART_ITConfig(USART6, USART_IT_RXNE, ENABLE);
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. e4 j& c6 d3 ]+ q- USART_Cmd(USART6, ENABLE);; b+ _, k ~1 S8 q! ]3 {! S
" j- B# B% w. v: I# c- USART_ClearFlag(USART6, USART_FLAG_TC);* I4 B7 k y# }: d. J0 A" ]7 W4 B
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. d1 c8 s. `6 a' ^4 g" c4.422串口中断的配置: - void USART422_NVIC_Config(void)
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C2 h% ^% }( F2 \ - NVIC_InitTypeDef NVIC_InitStructure;( Q: b6 l/ G9 f/ C; ]
- NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); //设置中断分组2
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) n3 b0 } t- R8 y- NVIC_InitStructure.NVIC_IRQChannel = USART6_IRQn; // 选择 USART6 通道
! P" o2 m- x2 a \6 m% \$ j4 | - NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; //抢占优先级设置为38 _' E, b: y2 Y* J3 A
- NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; //响应优先级设置为1
5 n) }- \- G7 Z& N - NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //开启中断, i8 N6 f: V8 b% A3 B7 Z
- NVIC_Init(&NVIC_InitStructure); //初始化配置; F4 G/ c; ?( d; P
- }
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( Q5 `6 C" S; @3 Z3 V- void USART6_IRQHandler (void)! {: w6 I( t! C ~* o
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( _6 O: S3 z! ~/ l9 V& K; Z; V7 I - char Date422 = 0;
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; ?' I3 m: T2 x: ?) A8 v5.主函数的发送: - int main(void)
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- Delay_Init(); //延时函数初始化- v0 y+ U7 s, w! o! J
- RS422_Config(); //422串口初始化( h4 U5 x+ P* Z' Q) [+ s
- while(1)* m( s, n3 m: y3 u- I+ W' t1 _
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- Delay_ms(1000);* R5 T+ D# ^( W
- USART_SendData(USART6,3); //将接收到的数据发回' A& [- H% O$ y: y3 F
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- }
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