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: . a5 J9 [/ e0 d
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2、HAL库中的us延时函数" u0 a3 E! |1 }& j
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 */7 D0 D# r# q! X1 V
- void delay_us(uint32_t Delay)
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+ K( X6 N- Z# ^6 S/ r - uint32_t cnt = Delay * 8; " H" U! g' s5 {' ~( S
- uint32_t i = 0;- w8 |4 Q6 a4 D7 K
- for(i = 0; i < cnt; i++)__NOP();
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4 }4 v! H( \5 g' I - /* USER CODE END 4 */
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' h! l( W5 B6 {# p0 }1 E3、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"9 x* v/ {4 h6 k$ j, B
$ g. l7 `- U/ x% [1 m2 y- // ------------------------------------------------------------------
: x7 |: u' ~: F$ P& F+ @ - void i2c_init(void) {, E% J) S* B$ \9 I
-
4 N1 X- e: k; ~7 A, p) L - // the SDA and SCL pins are defined as input with pull up enabled
( r( s; a" o. w8 x: ] - // pins are initialized as inputs, ext. pull => SDA and SCL = high" y7 u/ s, w4 E9 w3 D& m/ `" K
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- // ------------------------------------------------------------------
' z+ X A9 r" f - // send start sequence (S)
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8 N" t; O8 r5 G; O$ _! [/ l- void i2c_start(void) {
% T$ f4 L8 X; X: N. H - sda_high();
1 g7 R, @! X4 r7 p( E( d$ ]" N+ g - delay_us(10);3 Q* P+ E7 _9 i& d7 [/ K2 }% p
- scl_high();
8 z7 n* e9 q) Z% z9 o4 ? - delay_us(10);* W1 e! I( H. K, W" J7 q6 \- u
- sda_low();
2 d, ~ M" {7 L* p - delay_us(10);
( R) i8 L# T9 S* ~ - scl_low(); ) x# j) t* ^6 H# H5 B+ G, p
- delay_us(10);
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- // ------------------------------------------------------------------
6 C: [8 p$ J) y7 ~; R! E - // send stop sequence (P)
& l) l3 _; z7 L7 m2 J - void i2c_stop(void) { 1 s& t4 d8 Q. q5 F
- sda_low(); - N9 [/ ^/ j1 l
- delay_us(10);! \2 a; H8 b* t4 A" w
- scl_low(); - m+ g5 [/ {9 e, v' F, }" t) F
- delay_us(10); . L6 Y+ ?; b) q
- scl_high();
6 L* Z; e! A, h" v- F - delay_us(10); 2 N, A* T/ }- \. I$ J7 m; b8 L
- sda_high();, X" C, n8 F( n% T) B4 I# q
- delay_us(10);
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) H- i1 L6 P6 ^ F0 Y - // ------------------------------------------------------------------% G f# ?- w9 D! j4 {5 }$ S# h2 |
- // returns the ACK or NACK. G/ k2 X) X$ @4 Y3 R, s7 T/ n
- uint8 i2c_write(uint8 u8Data)
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4 Q9 X* ]6 I; \' G. l; X0 w - uint8 u8Bit;/ D h0 {4 h" N1 Y
- uint8 u8AckBit;) `. x/ J( O' E2 ]/ U
- // write 8 data bits, @5 R1 e- v5 T& M& `7 ]
- u8Bit = 0x80; //msb first
6 M6 }0 Y1 U" v* Z) a - while(u8Bit) {
, l$ [. f1 w* w+ U: m, L" X - if(u8Data&u8Bit) {
8 Y4 A- ?3 [& d8 n - sda_high();
6 \5 c4 n2 ~# g6 L: a5 u: e: ` - delay_us(20);5 w. c9 C1 ~6 x3 G m5 x+ R
- } 2 h& g) W' f ]: W
- //& compare every bit" l: ]: [1 \' U
- else{
# N, f; Y/ a- c1 H, m! }# R - sda_low();
& U! E* r- q, T5 r3 N8 x - delay_us(20);
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% Z! K9 v+ X' i1 F - scl_high();
, h# s9 a$ I& m/ T4 S7 _( `8 d: i" a1 { - delay_us(30);
7 s7 o. Q5 ]$ p! M$ ?' J - u8Bit >>= 1; ; C5 P U' D3 o* Y) [- k6 ]
- //next bit
+ `2 A! P8 t% ]% t" Z2 t - scl_low();
0 K1 H; a/ ^8 p# c: Y - delay_us(30);
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- // read acknowledge (9th bit) - ]+ c- Y" `3 }( a+ d
- sda_high();
; i; e% Q; |# P3 R7 Q) J* T - delay_us(10); $ W9 |& T% w+ L9 v
- scl_high();5 _# U+ j! X# q1 V6 ]
- delay_us(10);3 X: D% |! b7 I5 P* k7 v7 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 SCSEDIO0
3 \ D! n) l" X0 n8 U - delay_us(10);. n4 d' U. w4 U& Q0 X
- scl_low();
. E0 c3 P* U9 x! s7 g; V - delay_us(10);
/ ?% i4 ]- |1 Q; W& X4 M - return u8AckBit;! v e) |' Q5 B3 ]7 @4 u
- }
5 i( X6 r0 k" d, A - // ------------------------------------------------------------------, V3 i4 P. r2 {- R- {
- // pass the ack/nack
2 Y2 C! [% n, F, I2 u' n - // returns the read data " A* }9 N, G6 E- X& p* z
- uint8 i2c_read(uint8 u8Ack) ) n0 O G) |) ^4 R" L; B
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- uint8 u8Bit; v+ i1 c. M" B& J f
- uint8 u8Data;' z$ `, ]; Z a& _ h5 M
- u8Bit = 0x80; // msb first
" r4 l3 E" y7 A4 |, ~+ i/ b* p - u8Data = 0;" V. l; F7 T4 W( u( s
- while(u8Bit){
+ J9 E8 S& [+ [! I2 K" A0 w; w - scl_high();' \( Z+ y+ J0 A; D7 i7 ~
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- delay_us(20);
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- u8Bit >>= 1; //next bit
/ Q2 L% L W7 r - u8Data <<= 1;) z# u' j5 F8 M/ t( O6 N
-
2 \' F7 w( {! l+ r7 e, [7 n - u8Data |= sda_read(); //(sda_port & sda_pin)? 1 :0 sda_port gpio0 sda_pin SCSEDIO0
1 }, h3 X3 u- Y% G3 v- M3 B - delay_us(20);8 l* C0 d0 @: x. _5 J6 m$ [% n
- 0 p* ~3 j; e& N
- scl_low();7 O$ _8 i' h M) i
- delay_us(50);& ], q6 b+ _& f( o1 e$ K
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- // 9th bit acknowledge! j* ~- p" o1 R4 L5 e$ [# D" g
- if(u8Ack==I2C_ACK) {
, ], G) r6 \+ ]2 T, Q& W, a - sda_low();
) z" B R( n9 T - delay_us(20);, g* y0 G0 s9 J9 x* N/ F' D
- }
4 ?) ?2 ^0 E6 ^& a- c3 l; r - //I2C_ACK=07 @" t, u: C: t4 T
- else {
3 E# a; y2 m2 w+ h f% d; s - sda_high();
8 h4 v8 Y$ O: c2 Z - delay_us(20);' S2 `+ d' \# E# ~& e! y, Z7 i8 {
- }
2 t2 L& m8 n% T- `( s. l - scl_high();
/ V1 l6 W) T: O2 e' _ - delay_us(20);( ^8 ^" ]: J! R. @" Q( i
- scl_low();! t; D& A3 W1 i* \( ^0 b% o o
- delay_us(20);8 o9 z" g9 }& w4 f/ l4 l1 S
- sda_high();
0 _% q" B9 R$ L# g+ _, C) y7 u - delay_us(20); # R; K! X4 W U
- return u8Data; w$ j* M0 W* p* [; P) E, f
- }
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& D! ?1 `. X9 ~8 P' G/ r% ^i2c.h: - #ifndef _I2C_H_INCLUDED t* A6 }+ [ x) A" {
- #define _I2C_H_INCLUDED2 `& N' ^. _3 D' q9 i$ M
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- #include "main.h"
8 R# ]* b( b; _' q8 J' V0 G2 t - #include "Datadef.h"
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- // #define I2C_CLK_HIGH() HAL_GPIO_WritePin(sht_scl_GPIO_Port,sht_scl_Pin,GPIO_PIN_SET);7 k+ V" }. l) m& |
- // #define I2C_CLK_LOW() HAL_GPIO_WritePin(sht_scl_GPIO_Port,sht_scl_Pin,GPIO_PIN_RESET);- n: B& u: b5 f% n. ?& G) \' T* E/ X4 Z
- % s* x' Q1 n+ R" M0 a5 H; ]
- // #define I2C_DATA_HIGH() HAL_GPIO_WritePin(sht_sda_GPIO_Port,sht_sda_Pin,GPIO_PIN_SET);
" c; ^* Q: I: ]+ S% k - // #define I2C_DATA_LOW() HAL_GPIO_WritePin(sht_sda_GPIO_Port,sht_sda_Pin,GPIO_PIN_RESET); ; E9 T( u9 k" ?( e! n! i. [& v; P
- // #define I2C_DATA_STATE() (HAL_GPIO_ReadPin(sht_sda_GPIO_Port,sht_sda_Pin) == GPIO_PIN_SET); 2 b' m4 c6 ^1 P0 R# s# n
- 2 u" Z7 V0 F. D$ G8 T% ~( V" V
- // #define sda_high() I2C_DATA_HIGH() // set signals to HIGH first before selecting IN -> slew rates& g, Q- e! b: L7 i9 ?) z/ d
- // #define sda_low() I2C_DATA_LOW() * t. a, ~1 [3 q8 q/ K. n
- // #define sda_read() I2C_DATA_STATE() //ack on bus is low -> u8AckBit = 15 c! e) _9 k1 w- _
- & g+ v# z4 t, e9 m/ o8 {
- // #define scl_high() I2C_CLK_HIGH() // set signals to HIGH first before selecting IN -> slew rates4 W t J* |/ @% R3 K% S2 i- _5 U" h
- // #define scl_low() I2C_CLK_LOW() 6 }5 F+ I2 Y4 O- {6 `; `6 z
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- #define sda_high() HAL_GPIO_WritePin(sht_sda_GPIO_Port,sht_sda_Pin,GPIO_PIN_SET); 4 ?# \4 ~! l/ Q7 D
- #define sda_low() HAL_GPIO_WritePin(sht_sda_GPIO_Port,sht_sda_Pin,GPIO_PIN_RESET);
2 {) u3 j' M" q `; } - #define sda_read() (HAL_GPIO_ReadPin(sht_sda_GPIO_Port,sht_sda_Pin) == GPIO_PIN_SET);4 h. p+ u( V6 i) a( X* E+ r, B
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- #define scl_high() HAL_GPIO_WritePin(sht_scl_GPIO_Port,sht_scl_Pin,GPIO_PIN_SET);
2 i8 u1 P2 X2 m) v+ f, Z+ j' K { - #define scl_low() HAL_GPIO_WritePin(sht_scl_GPIO_Port,sht_scl_Pin,GPIO_PIN_RESET);. E8 L# [. P& u2 m' C: c
-
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% x- L1 H9 C! o, ]; @ - // ------------------------( ~% U- \4 i1 j J
- #define DONOTHING() {;}
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7 m5 u) f9 W. Y! g5 V- // ------------------------
1 ~1 J# n" ^. h2 p0 c% G - // command's
P8 J5 U" j. Z3 d4 o% ^& `/ Y - #define I2C_WRITE 0
# `2 a' _/ d5 M( y4 G; J( m - #define I2C_READ 1: W% Z e: T' J
- #define I2C_ACK 0
2 { E6 F' J& o1 H# C7 |& h! V - #define I2C_NACK 1
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- void i2c_init(void);+ r. B5 l1 ^# Y- T( M% h
- void i2c_start(void);# k7 B6 B: E( D- Y- [3 \
- void i2c_stop(void);
# [, F' E4 Y. F6 m" e$ g* _ - uint8 i2c_write(uint8 u8Data);+ ?4 e) M' ~8 j4 _8 s
- uint8 i2c_read(uint8 u8Ack);
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- #endif
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# M0 B4 H3 ]5 f: G, CSHT21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: . w# @! v. ^, `: B# Z% T
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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。
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