CAN通信是STM32中比较复杂的东西之一,它 的初始化主要分为两个部分,一个是CAN的初始化,一个是过滤器的初始化。自发自收只需要一个器件,CAN的模式选择回环(Loopback)模式,这种模式下发出的数据也会被CAN本身接收回来,只需要检查接收到的数据和发送的数据是否一样,就能测试发送是否成功。
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% V! ^8 t6 }" n4 B$ l- void CAN_Config(void); H& a# e" p# \
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- CAN_InitTypeDef CAN_InitStructure;
- s) g" j1 a7 U9 x - CAN_FilterInitTypeDef CAN_FilterInitStructure;6 F8 \" M0 g, u: t
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- RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1,ENABLE);
+ }& h8 [3 D4 p8 e1 ?" K( R; K - CAN_DeInit(CAN1);
( e! N7 Y8 n" f, R7 z - CAN_StructInit(&CAN_InitStructure);, n/ C* l! j$ } d
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- CAN_InitStructure.CAN_TTCM = DISABLE;
0 N' G7 ?# J' h( J& m0 v# C - CAN_InitStructure.CAN_ABOM = DISABLE;
$ M$ i L/ i% k/ q, V6 `5 K$ `& r5 l - CAN_InitStructure.CAN_AWUM = DISABLE;
2 s8 @" O3 x- x - CAN_InitStructure.CAN_NART = DISABLE;" Z/ O: y2 E1 ~/ G0 q2 S; g/ Q
- CAN_InitStructure.CAN_RFLM = DISABLE;
. M k9 ^. p0 a - CAN_InitStructure.CAN_TXFP = DISABLE;
! p9 O' m4 _; `8 {7 O% I2 f - CAN_InitStructure.CAN_Mode=CAN_Mode_LoopBack;//回环模式
- I# w! K1 b. G5 w - CAN_InitStructure.CAN_SJW=CAN_SJW_1tq;//1
/ A; a( G" a0 A, f - CAN_InitStructure.CAN_BS1=CAN_BS1_9tq;//9: T, o9 ]) Z( u: @
- CAN_InitStructure.CAN_BS2=CAN_BS2_8tq;//8& g! Z+ A9 J- h( [, _
- CAN_InitStructure.CAN_Prescaler=16;//16分频
$ E- J. H" [- V2 ] - CAN_Init(CAN1,&CAN_InitStructure);
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- CAN_FilterInitStructure.CAN_FilterNumber=0;
* v$ {' ^1 g) c% y - CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask;//屏蔽模式1 D3 t7 \% y. D4 v
- CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit;
0 i7 ?, |/ c9 v, g x9 X; v5 g4 Z - CAN_FilterInitStructure.CAN_FilterIdHigh = 0x0000;! p/ ^, ]6 i7 f/ x/ t
- CAN_FilterInitStructure.CAN_FilterIdLow = 0x0000;
; ^0 E: P. x B' Q2 V - CAN_FilterInitStructure.CAN_FilterMaskIdHigh = 0x0000;9 q$ |" x* C3 K' z t
- CAN_FilterInitStructure.CAN_FilterMaskIdLow = 0x0000; 6 X+ k# c; C3 Z! f/ H1 L. ]7 g
- CAN_FilterInitStructure.CAN_FilterFIFOAssignment = CAN_FilterFIFO0;
( E5 [% |1 u _. {6 J' t7 J; k1 v$ u - CAN_FilterInitStructure.CAN_FilterActivation=ENABLE;
. ~0 ^( i2 K5 T v/ ? - CAN_FilterInit(&CAN_FilterInitStructure);
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配置完成,开始发送和接收:5 J% K% I z$ x8 X8 v
- void CAN_Test(void), B" ]# [& F/ S1 h3 p8 q9 H
- {
0 c/ `8 }5 N# }4 g4 T+ J& g - CanTxMsg TXmessage;
$ \% h. E: d) c5 H" G: h - CanRxMsg RXmessage;1 v1 z8 K* {' m' l7 f, ]* i: q
- uint8_t TxMailbox=0;/ J1 u* r# x$ h
- uint8_t ret=0;
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- CAN_Config();
1 ~3 z$ r4 X1 o* i8 h: a) V - TXmessage.StdId=0x123;//ID,标识符
' k% {: m) C2 g9 |- B - TXmessage.IDE=CAN_ID_STD;//标准ID
- x8 q* W) Y8 H5 [, C+ z - TXmessage.RTR=CAN_RTR_DATA;//传送的是数据帧
7 r- s( F' z+ U- j$ k! N2 L - TXmessage.DLC=3;//数据个数。不能超过8个( f; n6 a/ a l. N
- TXmessage.Data[0]=0x01;//传送的数据
; I1 w; F: ~; a) W! B$ h$ S% p! J - TXmessage.Data[1]=0x10;% j4 w' K: z2 O1 f) q4 S
- TXmessage.Data[2]=0xFF;
5 B7 z3 q; m9 J$ v; G - TxMailbox=CAN_Transmit(CAN1,&TXmessage);//发送,返回的是当前邮箱号
8 V2 ~% K- {" J( `$ P% G9 m: ?9 u - while(CAN_TransmitStatus(CAN1,TxMailbox) !=CANTXOK);//等待发送完成
1 b9 C+ D# o* g; Z - while(CAN_MessagePending(CAN1,CAN_FIFO0)<1);//查询接受状态位,看是否有信息(报文)到达
7 \3 _1 H; U4 H2 ~ - RXmessage.StdId=0x00;//初始化接受结构体
+ R; F& {* C/ y& G - RXmessage.IDE=CAN_ID_STD;
4 O. x, d" ^& R2 h - RXmessage.DLC=0;
; o% V3 A3 @% b+ { - RXmessage.Data[0]=0; t% Y3 V1 t+ ^5 Z- A0 c
- RXmessage.Data[1]=0;! P+ j! F+ P) @$ v
- RXmessage.Data[2]=0;
' n; l2 M( u- q* c9 k4 M* f* d6 S - CAN_Receive(CAN1,CAN_FIFO0,&RXmessage);//接收信息(报文): p6 t( D6 S6 T s/ W
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- //最后检查所接收到的数据每一个项和发送的是否一样,如果全部一样则发送成功,否则发送失败
3 H5 }- Y* [& c/ P0 s! |* e: k - //设置标志位对结果进行保存,用串口打印或者LED显示不同的状态来表示发送接收情况2 |5 V) a% x; V$ r# M. o. S
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