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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+ \7 H6 n; t$ O) {2 G( x" v3 @* p2、HAL库中的us延时函数1 t, V" d, ~3 d# k1 ^# b
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 */
2 f. Y' A8 }* r - void delay_us(uint32_t Delay)
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- uint32_t cnt = Delay * 8; 4 _9 L2 ]% R# S! W8 Y
- uint32_t i = 0;
9 N) \( d+ Y' z1 ? - for(i = 0; i < cnt; i++)__NOP();* |6 p C- L6 D1 w$ F) T$ w
- }
5 x& [8 x) q! p" h0 F' a - /* USER CODE END 4 */
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/ B9 T, U$ Z, H: S1 _% z4 K/ D3、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"% z7 P6 A6 c; E4 P
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- // ------------------------------------------------------------------
) L/ Y8 B* K: U# I - void i2c_init(void) {
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, ]! B* B8 x* B1 j. P - // the SDA and SCL pins are defined as input with pull up enabled) F1 W/ X5 j% V1 l. {4 R
- // pins are initialized as inputs, ext. pull => SDA and SCL = high
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% s. q4 E# F! j - // ------------------------------------------------------------------
+ p# H: U) ?: T8 t b" @ - // send start sequence (S)
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- void i2c_start(void) {
$ u2 c0 v$ U8 e' l - sda_high(); + y% i d( S& g7 x/ \
- delay_us(10);
' b; y$ z8 {! d( W, G/ |# Q# z - scl_high();
7 @6 \, m, \" w5 c$ o/ f! w( ~! D - delay_us(10);
4 t: x- o4 g$ _' Z - sda_low();
7 D8 H' i" d0 K5 R/ Z% v& e - delay_us(10);* s. P3 o2 v8 @8 N* r
- scl_low(); & {/ T' \! ?% P$ t1 t
- delay_us(10);$ d2 q: O' K! g* d: t& V
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- // ------------------------------------------------------------------
7 E6 S) a8 H- h* ~+ b" {' G - // send stop sequence (P)
{( x$ _/ s' T3 w/ L7 K: n/ t- H - void i2c_stop(void) { 9 t8 ~6 V" M- m W/ k4 E* ^
- sda_low();
3 f/ e) O; `$ m8 m* t4 g - delay_us(10);0 n5 x5 @: |3 k5 _/ i n9 e8 f
- scl_low();
# i8 R$ x- |6 ]1 p) y0 i - delay_us(10);
3 s8 q8 Z. c% l# }" g- a - scl_high(); : R. R0 d( ?4 M3 B0 i. c
- delay_us(10); 6 ~0 o% r, X. G5 a- K' {
- sda_high();0 {- y0 O7 _ U
- delay_us(10);2 T" N% j. a1 H6 f2 ~# P7 {; w
- }
4 T5 M+ [. p, `' d6 A e" ` - // ------------------------------------------------------------------
& I9 O' Q) I$ h1 X M) ^ - // returns the ACK or NACK: ?* n9 M2 e9 r4 @: ~* q
- uint8 i2c_write(uint8 u8Data)
2 r% C+ z; S, n ?3 a. ? - {
$ y6 m& |$ n- E! |- G/ s - uint8 u8Bit;- q7 o5 E) X* f( Y& }4 P& d
- uint8 u8AckBit;2 `/ p4 W5 u4 U; g% w* L6 v
- // write 8 data bits* q+ Q! }+ C8 \. ~% |6 u( P
- u8Bit = 0x80; //msb first
/ n' `7 _3 x2 O) |) P, C6 s# U8 b" j6 O - while(u8Bit) {
: v) w0 \( l: C" ` - if(u8Data&u8Bit) {
- ?; Q( T: N! k( e# m( X1 `9 e' m - sda_high();
! q" n" K3 a& ^ - delay_us(20);
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- //& compare every bit
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- sda_low(); l! [' r9 n9 @ s' |* Z
- delay_us(20);5 x4 b9 W3 |& v
- }
4 u( |) F0 L5 M4 s5 ~) t( ?9 w' R1 N - scl_high();
. N4 z# V2 I8 R$ [ - delay_us(30);
$ j# C! b+ A3 `/ O/ B. h$ B* c - u8Bit >>= 1; ( f+ ~8 \' w3 B; R b9 J2 u
- //next bit
$ n1 e2 B5 l }' M& X - scl_low();
5 M d8 x7 a* Y8 L3 L( @ - delay_us(30);
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. B- C3 Y+ B' l - // read acknowledge (9th bit) 9 ]% |# c0 u4 r7 E" q4 n
- sda_high();
' ?$ R5 @# G0 ?2 b, ~ - delay_us(10);
& k5 L" M* l% F1 M1 w% e, R5 a - scl_high();
- _" d1 [8 C5 s' u! M S - delay_us(10);7 K6 P% h$ l* J1 E: z2 V* K* ?8 i
- 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
8 z8 Q* g/ m1 v T9 f7 ~" q - delay_us(10);
; f4 @. u j. `7 |. ~ o/ S - scl_low(); % V, H" ~% N8 f4 m, ^
- delay_us(10);
9 Q9 [* u* |. A% J - return u8AckBit;# ]) _& Q$ H1 `+ }9 \
- }
4 ^! g, D' o- s3 w - // ------------------------------------------------------------------
4 O/ s( h" L* X( h+ R9 m! S1 q6 _ - // pass the ack/nack @$ o% I/ d6 H- o# K! `" e
- // returns the read data
5 D+ c: x' @' ^/ s5 k7 j2 {% ^* h+ K - uint8 i2c_read(uint8 u8Ack)
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- uint8 u8Bit;8 G7 Q9 o# S3 N H0 F
- uint8 u8Data;6 c+ q+ _; Z3 x" ^; m7 g
- u8Bit = 0x80; // msb first* d; g; H* Y* G3 D% x: [; o4 v
- u8Data = 0;
6 r# S0 Z- G. l, ~& y s - while(u8Bit){7 `. M( v0 P" y! t- O
- scl_high();$ w( Q; ?2 K: d4 E' n# R7 V2 ?
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- delay_us(20);
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- u8Bit >>= 1; //next bit; p- S. E9 ^2 Q
- u8Data <<= 1;
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- c. Y Q: ]0 T" Y) f. a' M - u8Data |= sda_read(); //(sda_port & sda_pin)? 1 :0 sda_port gpio0 sda_pin SCSEDIO0
$ S5 a) s; @2 b4 c! P - delay_us(20);
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- scl_low();4 C. b' K% b1 M: W; w" R: @4 L5 m
- delay_us(50);/ v; b! l$ _! ^
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- // 9th bit acknowledge( x6 C* M) x! X) c5 o* p
- if(u8Ack==I2C_ACK) {
! ?) r! M$ V0 O0 } - sda_low();
]; S' b' W0 y7 Q7 g6 f1 D - delay_us(20);# ?% c9 U/ r' h5 j3 O
- }
/ L; [8 y, ~8 C+ V8 ?% `* J% X/ ?! C& q - //I2C_ACK=0
& n% G% h3 X/ p - else {
/ ?: S. b0 I8 F# X/ m - sda_high();
( m2 m, b6 y4 C: E) [6 k8 N. z" v - delay_us(20);
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/ a; {# ]) O3 ~ - scl_high();
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- scl_low();
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- sda_high();' H3 L- @: x$ ^! q1 [) w1 F# Y, |
- delay_us(20); : I% J, R' n" x5 a) i3 [: E% I
- return u8Data;3 G& K2 h8 J4 H) E. w. X- e
- }
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3 J- m( Z/ Z0 T0 G! Oi2c.h: - #ifndef _I2C_H_INCLUDED& ^- {! C1 O' v0 J* G7 j1 g
- #define _I2C_H_INCLUDED
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) t7 b. N$ p+ k. T& F- #include "main.h"4 V9 _7 g4 ~# |% b
- #include "Datadef.h"
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- // #define I2C_CLK_HIGH() HAL_GPIO_WritePin(sht_scl_GPIO_Port,sht_scl_Pin,GPIO_PIN_SET);
- B' R6 j3 C- e* Q a$ B/ @ - // #define I2C_CLK_LOW() HAL_GPIO_WritePin(sht_scl_GPIO_Port,sht_scl_Pin,GPIO_PIN_RESET);, e. y. V& x. `0 H) ~: I1 ~4 @+ ~
+ R7 a& Q) X) K3 K Y! c- // #define I2C_DATA_HIGH() HAL_GPIO_WritePin(sht_sda_GPIO_Port,sht_sda_Pin,GPIO_PIN_SET);
7 g, j0 e. D% f$ o- q& D+ t - // #define I2C_DATA_LOW() HAL_GPIO_WritePin(sht_sda_GPIO_Port,sht_sda_Pin,GPIO_PIN_RESET); / F! ]9 n* a# x4 N3 @8 r: b! s
- // #define I2C_DATA_STATE() (HAL_GPIO_ReadPin(sht_sda_GPIO_Port,sht_sda_Pin) == GPIO_PIN_SET);
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. Q2 A0 S& l. j! r- // #define sda_high() I2C_DATA_HIGH() // set signals to HIGH first before selecting IN -> slew rates0 m# [. g- K O0 W8 U8 F: z/ @
- // #define sda_low() I2C_DATA_LOW()
; J- t6 i- c; ^0 b+ I" H: z - // #define sda_read() I2C_DATA_STATE() //ack on bus is low -> u8AckBit = 1
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6 x0 Q' v4 x/ v: B- // #define scl_high() I2C_CLK_HIGH() // set signals to HIGH first before selecting IN -> slew rates
) X0 V5 ^: H0 q1 d - // #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);
& E' R1 ~$ ?2 h9 ` - #define sda_low() HAL_GPIO_WritePin(sht_sda_GPIO_Port,sht_sda_Pin,GPIO_PIN_RESET);
9 Q0 @, Y2 [# F2 ` - #define sda_read() (HAL_GPIO_ReadPin(sht_sda_GPIO_Port,sht_sda_Pin) == GPIO_PIN_SET); n7 n1 P( j. Z
3 j& Z& e! {2 {9 J* d0 H! I8 {0 Z. \- #define scl_high() HAL_GPIO_WritePin(sht_scl_GPIO_Port,sht_scl_Pin,GPIO_PIN_SET);7 |$ E. a8 _; V( M5 v/ p4 {' a: u
- #define scl_low() HAL_GPIO_WritePin(sht_scl_GPIO_Port,sht_scl_Pin,GPIO_PIN_RESET);
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- // ------------------------
+ P/ P) B$ |+ o3 Z4 I - #define DONOTHING() {;}
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- // ------------------------
! q4 h. w" o2 q/ r1 {4 W - // command's8 M. W0 }3 X4 r4 _
- #define I2C_WRITE 0
, x/ C2 l, A! z5 K: R- s; J4 X - #define I2C_READ 1
, {6 C3 \4 i. \2 m - #define I2C_ACK 07 S8 M6 a- C2 a3 |: n
- #define I2C_NACK 1
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- void i2c_init(void);
0 g. T' I! W8 T" }3 K1 v @ - void i2c_start(void);; h2 z: U! E" U' t3 t9 }
- void i2c_stop(void);
5 T" P/ t8 S+ v7 F - uint8 i2c_write(uint8 u8Data);
4 k( e: i6 n ` - uint8 i2c_read(uint8 u8Ack);
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; ~' L. F K; ]- #endif
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3 k! Z' q) K( F7 |7 S! L4 l0 \2 zSHT21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。 3 Q R9 ?) l7 R
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