[National Technology Low Power Series N32L43x Evaluation] 3. Key Driver + SPI_LCD Screen Driver

emmnn

[National Technology Low Power Series N32L43x Evaluation] 3. Key Driver + SPI_LCD Screen Driver [Copy link]

 

<i class="pstatus"> This post was last edited by emmnn on 2022-7-11 16:36 </i> **Table of Contents** [TOCM] # Preface After introducing the RTOS porting, today I will introduce the development and function demonstration of the key driver and SPI-LCD screen driver. #Key driver On the official development board, in addition to the reset and wakeup buttons, three more buttons are provided for us to use. In order to facilitate subsequent application development, I found a five-way switch and connected other IOs for demonstration. <ignore_js_op> <img style="cursor:pointer;" id="aimg_621042" aid="621042" src="/bbs/static/image/common/none.gif" onclick="zoom(this, this.getAttribute('zoomfile'), 0, 0, '0')" zoomfile="//bbs.eeworld.com.cn/data/attachment/forum/202207/11/151801enntjmqvvu7uweem.png" file="//bbs.eeworld.com.cn/data/attachment/forum/202207/11/151801enntjmqvvu7uweem.png" inpost="1" onmouseover="showMenu({'ctrlid':this.id,'pos':'12'})" /> <div class="tip tip_4 aimg_tip" id="aimg_621042_menu" style="position: absolute; display: none" disautofocus="true"> <div class="xs0"> <p><strong>1.png</strong> <em class="xg1">(99.83 KB, downloads: 0)</em></p> <p> <a href="javascript:;" class="loginf" >download attach</a> <a href="javascript:;" onclick="showWindow(this.id, this.getAttribute('url'), 'get', 0);" id="savephoto_621042" url="home.php?mod=spacecp&ac=album&op=saveforumphoto&aid=621042&handlekey=savephoto_621042">save to album</a> </p> <p class="xg1 y">2022-7-11 15:18 上传</p> </div> <div class="tip_horn"></div> </div> </ignore_js_op> This type of button has a total of 6 pins, one of which is grounded, and the remaining 5 pins represent 5 directions (up, down, left, right, and press) <ignore_js_op> <img style="cursor:pointer;" id="aimg_621047" aid="621047" src="/bbs/static/image/common/none.gif" onclick="zoom(this, this.getAttribute('zoomfile'), 0, 0, '0')" zoomfile="//bbs.eeworld.com.cn/data/attachment/forum/202207/11/152206v1cbduh8phub1c3u.png" file="//bbs.eeworld.com.cn/data/attachment/forum/202207/11/152206v1cbduh8phub1c3u.png" inpost="1" onmouseover="showMenu({'ctrlid':this.id,'pos':'12'})" /> <div class="tip tip_4 aimg_tip" id="aimg_621047_menu" style="position: absolute; display: none" disautofocus="true"> <div class="xs0"> <p><strong>1.png</strong> <em class="xg1">(260.18 KB, downloads: 0)</em></p> <p> <a href="javascript:;" class="loginf" >download attach</a> <a href="javascript:;" onclick="showWindow(this.id, this.getAttribute('url'), 'get', 0);" id="savephoto_621047" url="home.php?mod=spacecp&ac=album&op=saveforumphoto&aid=621047&handlekey=savephoto_621047">save to album</a> </p> <p class="xg1 y">2022-7-11 15:22 上传</p> </div> <div class="tip_horn"></div> </div> </ignore_js_op> Bring out the switch pin, connect it to the idle IO of the development board, and set the macro definition ```c #define KEY_PORT_GROUP GPIOB #define KEY_RCC_PERIPH RCC_APB2_PERIPH_GPIOB #define KEY_UP_PIN GPIO_PIN_2 #define KEY_DOWN_PIN GPIO_PIN_11 #define KEY_LEFT_PIN GPIO_PIN_10 #define KEY_RIGHT_PIN GPIO_PIN_1 #define KEY_PRESSED_PIN GPIO_PIN_0 ``` The rest is a very simple IO initialization and IO reading operation to obtain the button status. For specific code, please refer to the attached project. In the embedded development using single-chip microcomputer, the button can be said to be the most common module. Although for the MCU side, it only needs to perform simple IO reading operations, there are still many issues to consider in actual development. For example, how to do button debounce processing, and how to judge and process various button events (such as short press, long press, single click, double click) in actual applications. At the same time, how to ensure that the business logic of the entire button application processing can remain clear and not messy, and to complete all these while completing the function, this is still quite difficult. The reason why the button part is taken out separately here is mainly to recommend a simple and easy-to-use event-driven button driver module that was recently opened on Github. The GitHub address is as follows: [https://github.com/0x1abin/MultiButton](https://github.com/0x1abin/MultiButton) The code is written in pure C, the code is concise, and the readability is also very good. About 200 lines of code have realized various trigger events of the button, the scalability is also very good, and the business logic is also very clear (here I silently worship the big guy). ```c /** * <a href="https://en.eeworld.com/bbs/home.php?mod=space&uid=159083" target="_blank">@brief</a> Key event and callback registration* * <a href="https://en.eeworld.com/bbs/home.php?mod=space&uid=784970" target="_blank">@return</a> uint8_t */ uint8_t KeyRegister(void) { button_init(&dev_handler_s.dev_btn_s.btn_up, KeyS can, 0, KEY_UP_ID); button_init(&dev_handler_s.dev_btn_s.btn_down, KeyScan, 0, KEY_DOWN_ID); button_init(&dev_handler_s.dev_btn_s.btn_left, KeyScan, 0, KEY_LEFT_ID); button_init(&dev_handler_s.dev_btn_s.btn_ right, KeyScan, 0, KEY_RIGHT_ID); button_init(&dev_handler_s.dev_btn_s.btn_ok, KeyScan, 0, KEY_PRESSED_ID); button_attach(&dev_handler_s.dev_btn_s.btn_up, SINGLE_CLICK, BtnUp_Single_Clicked_Handler); button_attach(&dev_handler_s.dev_ btn_s.btn_down, SINGLE_CLICK, BtnDown_Single_Clicked_Handler); button_attach(&dev_handler_s.dev_btn_s.btn_left, SINGLE_CLICK, BtnLeft_Single_Clicked_Handler); button_attach(&dev_handler_s.dev_btn_s.btn_right, SINGLE_CLICK , BtnRight_Single_Clicked_Handler); button_attach(&dev_handler_s.dev_btn_s.btn_ok, SINGLE_CLICK, BtnOk_Single_Clicked_Handler); button_attach(&dev_handler_s.dev_btn_s.btn_ok, DOUBLE_CLICK, BtnOk_Single_Clicked_Handler) ; button_start(&dev_handler_s.dev_btn_s.btn_up); button_start(&dev_handler_s.dev_btn_s.btn_down); button_start(&dev_handler_s.dev_btn_s.btn_left); button_start(&dev_handler_s.dev_btn_s.btn_right); button_start(&dev_handler_s.dev_btn_s.btn_ok); dev_handler_s.dev_btn_s.btn_Timer = rt_timer_create("BTN Timer", BtnTimerCb, RT_NULL, 5, RT_TIMER_FLAG_PERIODIC); if (dev_handler_s.dev_btn_s.btn_Timer != RT _NULL) rt_timer_start(dev_handler_s.dev_btn_s.btn_Timer); } ``` According to the example demonstration, after porting to my project, the key part achieved the effect I wanted. (The source code part is only about 200 lines. If you have time, you can carefully study the code of the big guy and learn his programming ideas. You can learn a lot.) <ignore_js_op> <img style="cursor:pointer;" id="aimg_621078" aid="621078" src="/bbs/static/image/common/none.gif" onclick="zoom(this, this.getAttribute('zoomfile'), 0, 0, '0')" zoomfile="//bbs.eeworld.com.cn/data/attachment/forum/202207/11/155006pfuugmmv70u7ajj1.png" file="//bbs.eeworld.com.cn/data/attachment/forum/202207/11/155006pfuugmmv70u7ajj1.png" inpost="1" onmouseover="showMenu({'ctrlid':this.id,'pos':'12'})" /> <div class="tip tip_4 aimg_tip" id="aimg_621078_menu" style="position: absolute; display: none" disautofocus="true"> <div class="xs0"> <p><strong>1.png</strong> <em class="xg1">(8.84 KB, downloads: 0)</em></p> <p> <a href="javascript:;" class="loginf" >download attach</a> <a href="javascript:;" onclick="showWindow(this.id, this.getAttribute('url'), 'get', 0);" id="savephoto_621078" url="home.php?mod=spacecp&ac=album&op=saveforumphoto&aid=621078&handlekey=savephoto_621078">save to album</a> </p> <p class="xg1 y">2022-7-11 15:50 上传</p> </div> <div class="tip_horn"></div> </div> </ignore_js_op> #SPI-LCD screen driver After talking about the key driver module, let's talk about using the SPI interface of the MCU to drive the LCD screen. As for the screen, it is a very common SPI interface screen on Taobao. The seller will also provide some sample driver codes. <ignore_js_op> <img style="cursor:pointer;" id="aimg_621096" aid="621096" src="/bbs/static/image/common/none.gif" onclick="zoom(this, this.getAttribute('zoomfile'), 0, 0, '0')" zoomfile="//bbs.eeworld.com.cn/data/attachment/forum/202207/11/160029zllc188cllcc3213.png" file="//bbs.eeworld.com.cn/data/attachment/forum/202207/11/160029zllc188cllcc3213.png" inpost="1" onmouseover="showMenu({'ctrlid':this.id,'pos':'12'})" /> <div class="tip tip_4 aimg_tip" id="aimg_621096_menu" style="position: absolute; display: none" disautofocus="true"> <div class="xs0"> <p><strong>1.png</strong> <em class="xg1">(417.67 KB, downloads: 0)</em></p> <p> <a href="javascript:;" class="loginf" >download attach</a> <a href="javascript:;" onclick="showWindow(this.id, this.getAttribute('url'), 'get', 0);" id="savephoto_621096" url="home.php?mod=spacecp&ac=album&op=saveforumphoto&aid=621096&handlekey=savephoto_621096">save to album</a> </p> <p class="xg1 y">2022-7-11 16:00 上传</p> </div> <div class="tip_horn"></div> </div> </ignore_js_op> Looking through the data sheet and user manual of the chip, we know that the MCU has two SPI peripheral interfaces for us to use. Here we use SPI2. Looking at the data sheet about the definition of pin multiplexing, we use PB13 and PB15 to multiplex the CLK and MOSI pins of SPI2 respectively. <ignore_js_op> <img style="cursor:pointer;" id="aimg_621102" aid="621102" src="/bbs/static/image/common/none.gif" onclick="zoom(this, this.getAttribute('zoomfile'), 0, 0, '0')" zoomfile="//bbs.eeworld.com.cn/data/attachment/forum/202207/11/160823iur95b58u8268mzu.png" file="//bbs.eeworld.com.cn/data/attachment/forum/202207/11/160823iur95b58u8268mzu.png" inpost="1" onmouseover="showMenu({'ctrlid':this.id,'pos':'12'})" /> <div class="tip tip_4 aimg_tip" id="aimg_621102_menu" style="position: absolute; display: none" disautofocus="true"> <div class="xs0"> <p><strong>1.png</strong> <em class="xg1">(90.71 KB, downloads: 0)</em></p> <p> <a href="javascript:;" class="loginf" >download attach</a> <a href="javascript:;" onclick="showWindow(this.id, this.getAttribute('url'), 'get', 0);" id="savephoto_621102" url="home.php?mod=spacecp&ac=album&op=saveforumphoto&aid=621102&handlekey=savephoto_621102">save to album</a> </p> <p class="xg1 y">2022-7-11 16:08 上传</p> </div> <div class="tip_horn"></div> </div> </ignore_js_op> Other pin definitions are as follows```c #define SPI_SCK_RCC_PERIPH (RCC_APB2_PERIPH_GPIOC) #define SPI_RCC_PERIPH (RCC_APB2_PERIPH_GPIOB)//RCC_APB2_PERIPH_GPIOA /* RES Port/Pin definition */ #define RES_PORT (GPIOB) # RES_PIN (GPIO_PIN_14) /* DC Port/Pin definition */ #define DC_PORT (GPIOC) #define DC_PIN (GPIO_PIN_7) /* BLK Port/Pin definition */ #define BLK_PORT (GPIOB) #define BLK_PIN (GPIO_PIN_12) #define SPI_PERIPH (SPI2) #define define SPI_LCD_CLK (RCC_APB2_PERIPH_SPI2) /* Define port and pin for SDA and SCL */ #define SPI_SCK_PORT (GPIOB) #define SPI_SCK_PIN (GPIO_PIN_13) #define SPI_MOSI_PORT (GPIOB) #define SPI_MOSI_PIN (GPIO_PIN_15) ``` For other parts, refer to the official examples and screen driver examples. After modification, the screen can also light up normally. #Effect demonstration picture [attach] 621110 [/attach] #Problem record In the process of using the SPI interface to drive the LCD screen, a problem was found. At the beginning, I used PC7 and PB15 to multiplex the SCK and MOSI of SPI2 to drive the LCD, but in the actual use, I used a logic analyzer to capture the signal and found that the clock pin SCK always had no signal output. Later, the SCK pin was changed to PA10. After SCK was changed to PB13, that is, it belonged to the same GPIO group as MOSI, SPI can use the output signal normally. I don't know if the MCU's use of SPI requires that the IO ports must belong to the same GPIO group. I haven't spent time to do more verification. I haven't encountered this problem with other manufacturers' MCUs before, and I haven't seen any relevant instructions in the official documents. If someone knows the problem, I hope you can help me solve it. :Onion-39: The final project attachment is as follows: #Attachment <ignore_js_op> <img src="/bbs/static/image/filetype/zip.gif" border="0" class="vm" alt="" /> <span style="white-space: nowrap" id="attach_621120" onmouseover="showMenu({'ctrlid':this.id,'pos':'12'})"> <a href="javascript:;" class="loginf">N32L43X.7z</a> <em class="xg1">(679.87 KB, downloads: 7)</em> </span> <div class="tip tip_4" id="attach_621120_menu" style="position: absolute; display: none" disautofocus="true"> <div class="tip_c xs0"> <div class="y">2022-7-11 16:33 上传</div> 点击文件名下载附件 </div> <div class="tip_horn"></div> </div> </ignore_js_op>

lugl4313820

Are you using hardware SPI to drive it? If it is software SPI, you can use different ports. If it is hardware SPI, it should generally be one port. Please read the data sheet for details.

luojiazidi_87

However, in actual development, there are still many issues to consider. For example, how to debounce the key, and how to judge and handle various key events (such as short press, long press, single press, double press) in actual applications. At the same time, how to ensure that the business logic of the entire key application processing can remain clear and uncluttered, and to complete all of these while completing the function, this is still quite difficult. The reason why I put

freebsder

The post is well illustrated with pictures and text, and also includes a table of contents. The author has put a lot of effort into it.

emmnn

lugl4313820 posted on 2022-7-11 17:41 Is the OP using hardware SPI to drive it? If it is software SPI, different ports can be used. If it is hardware SPI, it should be one port in general...

It uses hardware SPI to drive. A while ago, the subsidiary's products used Huada's chips and there was no such problem.

lugl4313820

luojiazidi_87 posted on 2022-7-11 18:00, but in actual development, there are still many issues to consider. For example, how to do key debounce processing, and in actual applications, for various key matters...

It seems that you are a newcomer and may need to earn some points. I hope you can read the author's posts carefully and then reply to meaningful posts, which is also a respect for the hard work of posting. Come on!

eew_DPB3w3

I see your code remaps to AF0, PB13 corresponds to AF0. Is it that when PA10 and PC7 are configured as SCK, there is no configuration to remap to AF5, GPIO_InitStructure.GPIO_Alternate = GPIO_AF5_SPI2;