本帖最后由 黑溱郎 于 2015-1-7 10:54 编辑 5 q( z& z# e# n4 D & ?. i4 h# S( K 2 X; N( q. b5 {8 t2 I6 F5 D 下面是STM8的模拟串口实验例子 实验工具:STM8S103FP6最小系统版, ST-linkV2, PL2303转串口模块7 @9 e: \% e& @$ }* z1 R / l3 g- w$ _# k, D: Z7 k/ |% l& fq: m8 S. y& U; L6 B 步骤1、算出定时初值, STM8内部晶振为16M, 采用8分频后震荡周期 =8/16 =0.5us,所以发送或接受以为数据的采样定时器初值应为48~52; 下面为定时器初始化代码: void Tim2_Init(void); S2 d0 a' l4 a, I; l* ]8 T {; [* n4 T8 n4 E, {' U1 o TIM2_DeInit();7 i8 t) [0 l" j# w TIM2_TimeBaseInit(TIM2_PRESCALER_8, 48); TIM2_ClearFlag(TIM2_FLAG_UPDATE); TIM2_ITConfig(TIM2_IT_UPDATE, ENABLE); TIM2_Cmd(ENABLE); } # O, p) m1 w$ P/ x5 v$ Q2 l 步骤2、RXD和TXD初始化,RXD为上拉输入,TXD位推挽输出高电平 #define Uart_RXD_Init() GPIO_Init(GPIOD,GPIO_PIN_6,GPIO_MODE_IN_PU_NO_IT)% o9 W: a5 Z- O) m, Q1 g #define Uart_RXD_Status() GPIO_ReadInputPin(GPIOD,GPIO_PIN_6)& O2 }& \; y& W! A5 e #define Uart_TXD_Init() GPIO_Init(GPIOD,GPIO_PIN_5,GPIO_MODE_OUT_PP_HIGH_FAST)9 V& W( U' Z$ h8 ?$ p #define Uart_TXD_Out_HIGH() GPIO_WriteHigh(GPIOD,GPIO_PIN_5)& `+ ], f2 b* S4 n# k #define Uart_TXD_Out_LOW() GPIO_WriteLow(GPIOD,GPIO_PIN_5)* c9 {6 g# ^# ?. H7 L 步骤3、中断调用函数 void Uart_Interrupt(void)% `$ N8 D0 _% j9 F { uint8_t i;1 X9 C6 C0 {' G1 N ' }: P6 g w! y; Y2 Q0 V" s if(1 == flag_rxd_finish)6 c# E3 T# G! n' T1 t { flag_rxd_finish = 0;9 J7 i0 f- G5 p0 _$ V) g! {6 l flag_rxd_txd = 0; for(i = 0;i < TxXKCnt; i++)- q2 u5 R% m, e5 u3 `/ { { UartTxBuff= UartRxBuff; } } if(1 == flag_rxd_txd) // 为1,接收; O2 m( g1 H" [. N1 f$ }* A! W { Y& ~; H) X2 }( W Uart_Rx_Byte(); } else // 为0,发送 { Uart_Tx_Byte();; \% [) v' R2 T. _ } }! T: o/ f8 }+ t5 Y- C7 d3 D. g& i& ~ 步骤4、接收函数+ t6 f$ t G3 V; ^/ | static void Uart_Rx_Byte(void) j, z6 N/ E# V# A9 m" C {- k3 I) E! `) ^: `: a$ ~# A/ ~4 ` static uint8_t RxBitNum; //接收位计数7 C2 I! k+ i" S; b" C static uint8_t OverTime; //接收超时计时器. c$ P- t. z& |! [* `( [0 ` static uint8_t RxByteBuff; //一字节数据接收缓存 if(1 == Uart_RXD_Status())+ u5 B& O h, m, n4 _% y3 B { OverTime++;8 ~# h/ C ?. u% F* A/ } }2 @- D/ |6 n& d! {/ }: O) D; }6 l else+ d) Z3 g+ ]' c. {0 L { OverTime = 0;, d4 m# o2 |) }# a% _8 r- ? } if(OverTime > 44)3 j0 i4 F4 j! O( e4 e" e { OverTime = 0; RxByteIndex = 0;% y- Q1 ^/ G; ~ RxBitNum = 0;- m! Z1 {8 C; A4 {, c% { \ }8 n9 n+ E1 M5 C0 }5 O ; |1 }8 U/ T- ~, T+ M; D if((1 == Uart_RXD_Status()) && (0 == RxBitNum)) { ]+ p. @& p0 k7 x6 \( F* R( ^9 Z RxSampFreq = 0;1 c. ]% C* W* C- x- _ } else {, J( o% I1 U/ B RxSampFreq++;) L" H7 t# z) W' t# D6 e }4 y. x7 U5 [ A' G0 I/ W if(1 == RxSampFreq) {9 ?2 V: A* ~, l8 a if(0 == RxBitNum) { if(0 == Uart_RXD_Status())5 E3 c+ X, { \6 z( D4 C { RxByteBuff = 0;/ a3 l3 @% { ` RxBitNum++;5 q0 E; Z: {3 |9 v* c( h5 k } }' W; u2 F. K; H( M) O Z else if((RxBitNum > 0) && (RxBitNum < 9)) {, ^$ L. V6 m l" V: ], S if(1 == Uart_RXD_Status())+ R1 N: V8 e3 s6 G { RxByteBuff = RxByteBuff | (1 << (RxBitNum - 1));2 z+ Z) T! |( h! E$ q& n1 ^# D } RxBitNum++; } else if(9 == RxBitNum) { if(1 == Uart_RXD_Status()) { RxBitNum = 0; if(0x0d != RxByteBuff && 0x0a != RxByteBuff) {( H6 a0 i/ v; G; c8 P UartRxBuff[RxByteIndex] = RxByteBuff;' k" n: i$ e) V) T RxByteIndex++;4 J, u& x6 V! D& w3 t if(RxByteIndex > 63) { RxByteIndex = 0;& A, ^5 _/ {+ l4 g3 ^5 P9 d }) R9 _+ `: f$ |2 y+ k }0 o; H: ~ {+ V7 v6 N# L4 c else. a3 Z A3 N- |2 V {9 n) G, {9 T6 h6 ]" C TxXKCnt = RxByteIndex;2 m2 c. x+ L' G# {" f2 W2 n RxByteIndex = 0;$ F' s" Q+ w7 e8 o7 f/ o flag_rxd_finish = 1;3 P+ B$ ~8 O& G/ k& {) G2 P }; W G" V" v7 N: R. d$ }9 \ }. e( E1 q; s9 B } else { RxBitNum = 0; } }( q) U; b$ L8 g( r4 e else if(RxSampFreq > 3) {' z( v! {% S, c$ M RxSampFreq = 0;6 P1 x- n. t0 R# @ V3 i }/ N0 K2 G$ ^8 i }8 A" w1 F4 }) `' v! k ! _0 }$ R! f8 ^ 贴子超长,接下页。 ; T5 g% n- w" E6 d7 i3 A; c 0 O9 Z, @9 W6 ]! I+ j % {% W/ Z7 d, f* e ' N4 T8 ^% S' d & V, [/ H7 ?3 h8 @2 X5 h* h ) U0 }9 \, _$ W4 R. k: U: ] |
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接上页。
步骤5、发送函数
static void Uart_Tx_Byte(void)- S# C" [( E& {. u8 L4 [' D) k
{
static bool SendFinish = 1; //发送完成标志
static u8 TxSampFreq = 0; //发送计数 采样4次& D: v/ L+ U+ X# K; B- z/ u
static u8 BitNum = 0; //位计数
static u8 ByteLock; //发送字节锁定(防止在发送途中 发送数字被改变)* H* c& @, B8 @4 L }/ P9 r
static u8 TxIndex = 0; //当前发送索引
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if(SendFinish)
{
SendFinish = 0;6 ~# |! J. a8 z5 e4 v
RxSampFreq = 0;
BitNum = 0;
if(TxIndex < TxXKCnt) //控制发送的字节
{
ByteLock = UartTxBuff[TxIndex];7 A0 W8 h U3 }# g
TxIndex++;1 U% X7 V4 n8 ?# g# \
RxByteIndex = 0;
}
else if(TxIndex == TxXKCnt). k' D: y+ W' q
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ByteLock = '\n';: T; m$ Z# ?4 ~7 m
TxIndex++;
RxByteIndex = 0;
}
else
{
flag_rxd_txd = 1;/ f% Y) `) |- C' J9 I! ?4 {
SendFinish = 0;: j0 J% B" ]$ K
TxIndex = 0;1 O! b+ I0 `' K+ _3 d
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}
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if(++TxSampFreq > 3)
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if(BitNum == 0) //起始位
{
Uart_TXD_Out_LOW();
BitNum++;
}
else if((BitNum >0) && (BitNum < 9)) //数据位
{
if(0x01 & (ByteLock >> (BitNum-1))) //先发低位! Z# n9 r6 t5 K* W
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Uart_TXD_Out_HIGH();% [1 B2 G4 K) @2 u; ]; i
}; ?, @% `/ e2 P* l
else! b; }* M B* z+ X9 B. c- Z5 V
{
Uart_TXD_Out_LOW();2 O: W6 K5 D2 v0 R
}
BitNum++;, h0 y$ [4 r2 {# o" k" s
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else if(BitNum == 9) //结束码
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Uart_TXD_Out_HIGH();
SendFinish = 1;
BitNum = 0;
}
TxSampFreq = 0;. P* w$ K1 o8 y% ]6 W- u7 V# T6 H
}
}% S" q' A- E5 s
当然可以的,我还打了板的
能正常运行啊!