1、CubeMX IO口的设置 模拟I2C的IO口都设置为开漏输出,因为电路图上有外部上拉。初始化的时候,2个SDA和SCL都得拉高。所以设置如下:
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% k/ f5 W+ F1 n* X2、HAL库中的us延时函数
# y$ h: T O5 u在HAL库中,只有ms的延时函数HAL_Delay,没有us的延时函数,今天用了网上一个延时函数,发现有问题,搞得整个时钟出了问题,郁闷,折腾了一下午。时间浪费了,通讯模块那边因为这个时钟设置也出了点问题,一直返回复位信息,用了怎么多年的芯片还第一次遇到,Enocean 的TCM310模块,主要这个技术支持也不太好找。= =!还是快速找一个us函数,不是那么精确也可以,直接用空语句测试,后面已经经过测试,下面这个函数做的us延时可以正常移植以前的I2C程序。 - /* USER CODE BEGIN 4 */" w! G3 q# C v8 n( i
- void delay_us(uint32_t Delay). u) }/ N! X5 A- b% O b% ~# g
- {
. {7 U- A( w9 i5 K4 N0 U5 } - uint32_t cnt = Delay * 8;
0 a8 `7 `6 B' q& B - uint32_t i = 0;5 i6 L) ^% z3 _) N' ?: _ B
- for(i = 0; i < cnt; i++)__NOP();
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- /* USER CODE END 4 */
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0 [7 e3 K$ r8 j3、移植I2C代码3.1 SHT21温湿度传感器代码移植没什么问题, i2c.c: - #include "i2c.h"
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5 z# N4 F4 j5 U0 e- }& w- // ------------------------------------------------------------------
8 X+ ~' m5 n0 L: P/ w - void i2c_init(void) {4 z; q' Z9 m3 Q# F# p; r
-
. s" _$ R& ^. o1 C9 m/ t - // the SDA and SCL pins are defined as input with pull up enabled: L. ^5 o5 C: b
- // pins are initialized as inputs, ext. pull => SDA and SCL = high
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- // ------------------------------------------------------------------; @8 j" O7 t" K; w s: O4 C
- // send start sequence (S)
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/ [3 p( Q$ \" c t+ k1 t- void i2c_start(void) {
" ?" U) N# L/ J/ t - sda_high(); 6 d1 O& ^# {5 z7 O: G4 [1 \
- delay_us(10);
! ^; X, Y# g2 i2 F- ]8 o - scl_high();
6 l& P' n5 J* ^5 u: L5 c# v/ j - delay_us(10);, ?" c: W4 E; y5 y3 A
- sda_low();
* L; k, {- S) K+ t# V( M/ Q - delay_us(10);' X3 `- I. q3 s+ w# U0 Q& q
- scl_low(); # ]& _2 K1 v7 V0 e
- delay_us(10);
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! b* D6 M% a. G" i: d - // ------------------------------------------------------------------
^4 s: @1 U7 O- t - // send stop sequence (P)5 T" {! d6 e8 V5 {
- void i2c_stop(void) { 4 B+ @) P9 J# u) S/ A, o
- sda_low(); 1 ]1 a, O: Q4 u
- delay_us(10);6 ~: l' i5 k6 ~ I" s
- scl_low();
5 J( Y+ {: r, j- [ - delay_us(10);
& @9 p' t3 ~6 Y) q - scl_high(); & j8 Q6 X' _7 Y4 N
- delay_us(10);
! L3 v) P! x8 Z6 } - sda_high();% h- B) ?" R. G9 \: v: ^' u) v) X
- delay_us(10);
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! O! w$ J+ e. g) ^+ v T% j - // ------------------------------------------------------------------- p- D8 a6 J+ A
- // returns the ACK or NACK D3 ?/ r9 }( Q/ o
- uint8 i2c_write(uint8 u8Data)
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- uint8 u8Bit;
" U5 k6 [4 x$ D) \ - uint8 u8AckBit;
# h% p6 J1 C, m7 i7 ?6 Z9 X - // write 8 data bits* w( B8 {$ m3 N' ~
- u8Bit = 0x80; //msb first
+ q& k" ]% n' a: C z - while(u8Bit) {- h. t6 ^+ J, s( N$ h5 Z
- if(u8Data&u8Bit) {
* ~8 H( K. ~, u, _# B - sda_high(); q5 J6 ]' B& U; v6 x. f" }
- delay_us(20);- B E8 [* e$ n
- }
. w9 |( F; ?( j0 M L8 f9 B - //& compare every bit
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- sda_low();
" R. l- P6 V9 V8 Q* j - delay_us(20);) w2 K' l2 T$ T( f
- }
\ }4 J g9 g+ ] - scl_high();
5 l7 Q! W# O! H3 p5 {- P - delay_us(30);
, J$ W8 |+ B) R/ D; H3 ~- R - u8Bit >>= 1;
) l+ p$ i- P" o* Z: |7 G& u2 \- j - //next bit
, D$ m5 c& d0 _* e3 a, H - scl_low();/ t; K0 n4 g6 t' Z3 o
- delay_us(30);
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- // read acknowledge (9th bit) 5 N) u5 b; `% B- d
- sda_high();
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- scl_high();9 X/ Z4 {, K/ E9 l. w+ c& M
- delay_us(10);8 } Z& s: b% I& [: h
- u8AckBit= sda_read(); //#define sda_read() (sda_port & sda_pin)? 1 :0 ack on bus is low -> u8AckBit = 1 sda_port gpio0 sda_pin SCSEDIO02 s1 A a6 f3 x# u
- delay_us(10);
$ Q5 d @) C$ O- r1 Q- r2 i - scl_low();
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- return u8AckBit;
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- // ------------------------------------------------------------------
! l. Z) ~0 v A' g4 w - // pass the ack/nack
. `4 s& U$ }% l+ \9 N# a - // returns the read data
' u9 h5 t. n$ s& s* k( P# | - uint8 i2c_read(uint8 u8Ack)
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9 U/ l, n4 R2 Q2 s) M$ z - uint8 u8Bit;4 h3 D4 w2 ~3 H2 G2 e
- uint8 u8Data;4 l4 X- F n) G
- u8Bit = 0x80; // msb first7 w/ D9 G ^( b; H
- u8Data = 0;4 W* W6 y9 a" n
- while(u8Bit){/ h% z* K5 V+ \1 o! S F/ ?
- scl_high();2 t! y Q' g8 P M) E
-
- M3 G! F1 g) v% I) d7 Y. B* _9 ?) t - delay_us(20);
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0 w0 T9 [; V# G3 h0 y - u8Bit >>= 1; //next bit
9 p1 L3 d! p/ R: ?3 r6 A2 X - u8Data <<= 1;
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- u8Data |= sda_read(); //(sda_port & sda_pin)? 1 :0 sda_port gpio0 sda_pin SCSEDIO0
7 a8 `6 m3 [% z" J# O! e' s - delay_us(20);
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) Q- V0 }! g; M; E: t" \ - scl_low();
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" e& t; J7 Q! H+ n; [ - // 9th bit acknowledge
1 O6 s, H' d; T6 M - if(u8Ack==I2C_ACK) {
0 C* Z% B% s" O! @2 `5 l: y - sda_low();/ @2 I6 I% i( d- ^( V* g- [& o
- delay_us(20);+ ^$ q+ u# O0 G9 G/ |1 K
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- //I2C_ACK=0
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- sda_high();
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- scl_high();4 `8 {+ L: L- V! I/ H' `' U
- delay_us(20);: G: C! P: A* i; K% E" A3 o
- scl_low();
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- sda_high();
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- return u8Data;
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% J( v) m u; f) K. Fi2c.h: - #ifndef _I2C_H_INCLUDED4 E) p5 b: c* \3 F# l1 B
- #define _I2C_H_INCLUDED& X# B/ `* S6 {; ~0 V, H Z: B/ J
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- #include "main.h"
* h$ r1 w3 `5 C; j4 V: ~; d - #include "Datadef.h"
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# H+ d' F2 Q0 B7 |" _3 g e; ~ - // #define I2C_CLK_HIGH() HAL_GPIO_WritePin(sht_scl_GPIO_Port,sht_scl_Pin,GPIO_PIN_SET);- N5 h4 { D8 G3 q* {
- // #define I2C_CLK_LOW() HAL_GPIO_WritePin(sht_scl_GPIO_Port,sht_scl_Pin,GPIO_PIN_RESET);; s2 y5 O, a2 U9 o: o8 S
- @+ ^6 j) J3 Y V$ a! n8 R- // #define I2C_DATA_HIGH() HAL_GPIO_WritePin(sht_sda_GPIO_Port,sht_sda_Pin,GPIO_PIN_SET);
& B2 h: }6 R4 F( h ~ - // #define I2C_DATA_LOW() HAL_GPIO_WritePin(sht_sda_GPIO_Port,sht_sda_Pin,GPIO_PIN_RESET); & I0 M( j( j2 o* {* r
- // #define I2C_DATA_STATE() (HAL_GPIO_ReadPin(sht_sda_GPIO_Port,sht_sda_Pin) == GPIO_PIN_SET);
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- // #define sda_high() I2C_DATA_HIGH() // set signals to HIGH first before selecting IN -> slew rates
* \3 k7 Z S( u7 V5 { - // #define sda_low() I2C_DATA_LOW()
8 }3 c+ Q& ?9 P9 Q+ X2 r9 E# d* f - // #define sda_read() I2C_DATA_STATE() //ack on bus is low -> u8AckBit = 1* O* C9 _6 G' }3 B7 y9 y4 |8 f
3 M5 W9 x. X2 ?( b! l! b- // #define scl_high() I2C_CLK_HIGH() // set signals to HIGH first before selecting IN -> slew rates
3 T/ B; A" D$ G7 [' F - // #define scl_low() I2C_CLK_LOW()
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- #define sda_high() HAL_GPIO_WritePin(sht_sda_GPIO_Port,sht_sda_Pin,GPIO_PIN_SET);
' G5 D) c5 a8 ]+ l' n+ N - #define sda_low() HAL_GPIO_WritePin(sht_sda_GPIO_Port,sht_sda_Pin,GPIO_PIN_RESET);* ~- M; s4 U& l/ G. r- A! C
- #define sda_read() (HAL_GPIO_ReadPin(sht_sda_GPIO_Port,sht_sda_Pin) == GPIO_PIN_SET);, U7 a0 B% z' J) k7 c" S6 _
1 d: z2 L7 H' [/ |; | j% e- #define scl_high() HAL_GPIO_WritePin(sht_scl_GPIO_Port,sht_scl_Pin,GPIO_PIN_SET);& j; m0 M1 Q4 Y# I
- #define scl_low() HAL_GPIO_WritePin(sht_scl_GPIO_Port,sht_scl_Pin,GPIO_PIN_RESET);. `. p. c$ A+ U ]
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6 k1 z) X0 L! K. P - // ------------------------* j* G$ X1 @- {" ~/ m9 @
- #define DONOTHING() {;}
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- // ------------------------7 o) u g) Q5 F4 |& U. p g
- // command's
4 v4 F) E6 i9 p# Y% u# r7 M - #define I2C_WRITE 0
- w9 b4 J2 {* K: t4 N2 n; R1 u - #define I2C_READ 1
0 a% g0 @ g. j6 ?4 A. c - #define I2C_ACK 0
# V0 d. W2 Q5 U0 B. H% \ - #define I2C_NACK 1
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: [9 f( g1 f4 @& n I& L+ i- void i2c_init(void);4 d& ^& b: ?6 C# D
- void i2c_start(void);
& q, b! E1 I& T7 r0 u5 N: b4 m - void i2c_stop(void);
: g, ~8 T2 z7 b) X0 |" g4 g9 r - uint8 i2c_write(uint8 u8Data);
5 a+ P+ R% Q3 B/ L) v - uint8 i2c_read(uint8 u8Ack);9 S# N( _- J# P7 z
0 t! J' ?4 l! z% Q- #endif
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2 B1 p- ]( A: J1 |4 NSHT21部分的驱动就不用怎么修改了,基本上直接拿过来,把ms延时函数替换一下,就直接用,这里就不贴出来 测试结果:
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板载的HTU21D,实际测试下来,一直会比空气问题高一点,这个问题,我倒是有点头疼,虽然做过分割,不铺铜等一些处理,还是不尽如人意。 ) r( ?$ L2 I4 Q& u& R
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