例程中没有输出变量，接下来的任务就是通过串口输出 ADC1 的值了。
, B1 G# c, G. V. a  v
- G6 ^  U1 |+ T8 }! |根据板子的设计，将串口输出到 USART3_PD9，USART3_PD8。通过新建立的项目完成硬件配置，主要是将 ADC 的函数拷贝到项目中。
: t& M8 v, @6 c3 M9 h

1. /**
   
2. 
   
3. * @brief USART3 Initialization Function
   
4. * @param None
   - X/ F8 O( |) y
5. * @retval None
   
6.   */static void MX_USART3_UART_Init(void)
   
7.   {
   
8. 
   
9. /* USER CODE BEGIN USART3_Init 0 */
   + p: H% k% R: ]% _- J! S. [5 v
10. 
    
11. /* USER CODE END USART3_Init 0 */
    
12. 
    9 H" a- o$ R( t' X6 e
13. /* USER CODE BEGIN USART3_Init 1 */
    
14. 
    
15. /* USER CODE END USART3_Init 1 */
    , m& I3 {4 {6 @* Z
16. huart3.Instance = USART3;
    
17. huart3.Init.BaudRate = 115200;
    
18. huart3.Init.WordLength = UART_WORDLENGTH_8B;
    
19. huart3.Init.StopBits = UART_STOPBITS_1;
    2 F% N5 c6 I4 T( u3 @
20. huart3.Init.Parity = UART_PARITY_NONE;
    6 K+ I9 v, B; Z+ a; J
21. huart3.Init.Mode = UART_MODE_TX_RX;
    
22. huart3.Init.HwFlowCtl = UART_HWCONTROL_NONE;
    7 q" _$ ]7 A; ~3 l: ^, A2 |
23. huart3.Init.OverSampling = UART_OVERSAMPLING_16;
    * u3 x# S- q# k
24. huart3.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
    
25. huart3.Init.ClockPrescaler = UART_PRESCALER_DIV1;
    7 @' P# G  e' v, x4 M0 T
26. huart3.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
    
27. if (HAL_UART_Init(&huart3) != HAL_OK)
    
28. {
    $ D5 x( L+ |/ ~1 K/ v
29.    Error_Handler();
    % S0 J9 j5 M3 e5 U
30. }
    
31. if (HAL_UARTEx_SetTxFifoThreshold(&huart3, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)
    4 j5 _) j8 P* `
32. {
    
33.    Error_Handler();
    
34. }
    ) _2 ?" S$ Z0 s: a4 S
35. if (HAL_UARTEx_SetRxFifoThreshold(&huart3, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)
    
36. {
    ' C+ x: h. |: H4 }$ s
37.    Error_Handler();
    / z0 G) T* L7 W9 K' e$ l4 z
38. }
    
39. if (HAL_UARTEx_DisableFifoMode(&huart3) != HAL_OK)
    
40. {
    
41.    Error_Handler();
    
42. }
    
43. /* USER CODE BEGIN USART3_Init 2 */
    8 s/ L6 G2 _; d
44. 
    
45. /* USER CODE END USART3_Init 2 */
    . K$ d* s5 M7 ?, E4 t
46. 
    8 m5 `4 N! Y* F5 x6 j- M% j" [
47. }

复制代码

0 C5 w* f- K& p: m: G# y将例程拷贝到例程中，然后是 printf 函数的设置，main.c 中包含 #include <stdio.h>

1. #if defined(__ICCARM__)
   
2. /* New definition from EWARM V9, compatible with EWARM8 */
   1 ^% S; A/ L5 h3 t/ Z5 M
3. int iar_fputc(int ch);
   
4. #define PUTCHAR_PROTOTYPE int putchar(int ch)
   8 {# P. |, W2 f) v$ w
5. #elif defined ( __CC_ARM ) || defined(__ARMCC_VERSION)
     ]4 ^  l5 L) W! A
6. /* ARM Compiler 5/6*/
   / c( ~6 e9 L1 n- a$ P: P/ u
7. #define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
   2 c6 f6 y1 j- M* o
8. #elif defined(__GNUC__)
   
9. #define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
   * i8 }1 o; i0 Q5 R) A2 T9 B! p
10. #endif /* __ICCARM__ */

复制代码

7 h! ]: a3 J0 j: j还有就是声明 PUTCHAR_PROTOTYPE 宏。
9 E" R; S# _- J* @

1. /* USER CODE BEGIN 4 */
   # G, H5 E4 L9 a! ]$ V  Y" r; B
2. /**
   8 I; G5 W6 V3 G
3. 
   1 h6 y* V8 F/ S
4. * @brief  Retargets the C library printf function to the USART.
   
5. * @param  None
   
6. * @retval None
   
7.   */
   
8.   PUTCHAR_PROTOTYPE
   * J8 f5 a8 r, N, \! m. R0 Z
9.   {
   
10.   /* Place your implementation of fputc here */
    
11.   /* e.g. write a character to the USART1 and Loop until the end of transmission */
    
12.   HAL_UART_Transmit(&huart3, (uint8_t *)&ch, 1, 0xFFFF);
    8 W2 G2 O  a0 k8 l4 [
13. 
    / W2 }7 x- b9 X
14. return ch;
    , |+ Z" P9 t8 h6 @8 Y9 i
15. }
    & w0 Y& [0 ]1 W: R/ B, l
16. /* USER CODE END 4 */
    

复制代码

还需要一个 keil 的设置 MicroLib。

1. while (1)
   
2. {
   / ~2 r* \7 R% a  p$ h
3.    /* USER CODE END WHILE */
   - ?' ?3 Y. c. e5 B/ }0 f
4. /* Start ADC group regular conversion */
   ; E7 w) V& F0 v
5.    if (HAL_ADC_Start_IT(&hadc1) != HAL_OK)
   
6.    {
   % W" G. A1 v7 k4 i7 [
7.      /* Error: ADC conversion start could not be performed */
   
8.      Error_Handler();
   ; a* `3 }; V3 [7 V1 w5 W2 o
9.    }
   
10. 
    
11.    /* For this example purpose, wait until conversion is done */
    5 a  Q: _5 \, S2 z0 e3 w, l
12.    while (ubAdcGrpRegularUnitaryConvStatus != 1);
    
13.    printf("mVolt=%d \n",uhADCxConvertedData_Voltage_mVolt);  
    
14.    /* Reset status variable of ADC group regular unitary conversion */
    
15.    ubAdcGrpRegularUnitaryConvStatus = 0;
    5 z8 k: W7 ^9 W9 u: p
16. HAL_Delay(500);
    
17.    /* USER CODE BEGIN 3 */
    
18. }

复制代码

下面是输出的结果
8 p9 r+ Q5 `) i- u5 e5 p
6 O6 h9 M1 \) @3 @6 e测试中我使用了我的一个宝贝，信号发生器。ADC 的性能和以往的ST差不多。

来源：EEWORLD论坛网友 bigbat 版权归原作者所有
+ i$ i0 p- H" j+ ?# M  h  i& ?

+ E* h% T' o, N+ _