定时、测温、报警、控制.... - 寒假在家一起练（4）演示by叶开

内容介绍

本次项目所要实现的功能

实现一个可定时时钟的功能，用小脚丫FPGA核心模块的4个按键设置当前的时间，OLED显示数字钟的当前时间，精确到分钟即可，到整点的时候比如8:00，蜂鸣器报警，播放音频信号，最长可持续30秒；
实现温度计的功能，小脚丫通过板上的温度传感器实时测量环境温度，并同时间一起显示在OLED的屏幕上；
定时时钟整点报警的同时，将温度信息通过UART传递到电脑上，电脑上能够显示当前板子上的温度信息（任何显示形式都可以），要与OLED显示的温度值一致；
PC收到报警的温度信号以后，将一段音频文件（自己制作，持续10秒钟左右）通过UART发送给小脚丫FPGA，蜂鸣器播放收到的这段音频文件，OLED屏幕上显示的时间信息和温度信息都停住不再更新；
音频文件播放完毕，OLED开始更新时间信息和当前的温度信息

设计思路

由于这是我第一次使用FPGA，我还是倾向于使用别人验证成功的代码修改拼凑成一个完整的功能，感谢每一个在为学习FPGA和完成任务途中帮助过我的人、团队和工具，谢谢大家。方案导图如下

FmAyMMveRNasEt0hkP9feMQFBqoG

具体实现DS18B20温度计模块

读取DS18B20的代码引用自电子森林的应用案例及参考代码，代码省略，输出一个16位的温度

16位的温度经过转换分割成个位十位和小数点后一位，由于此FPGA不能运算除法，使用打表，代码如下

always @(posedge sys_clk or negedge sys_rst_n) begin
   //最后四位为小数
   case(data[3:0])
       4'b0000: unit <= 4'd0;
       /* 中间省略 */
       4'b1111: unit <= 4'd9;
       default: unit <= 4'd0;
   endcase
   //只处理0-40摄氏度数据
   case (data[11:4])
       8'b0   : begin hun = 4'd0; ten = 4'd0; end
       /* 中间省略 */
       8'b100111: begin hun = 4'd3; ten = 4'd9; end
       default     : begin hun = 4'd0; ten = 4'd0; end
   endcase
end

代码略长，这里我使用python来生成代码

for a in range(2):
   for b in range(2):
       for c in range(2):
           for d in range(2):
               print("4'b%d%d%d%d: unit <= 4'd%d;"%(a,b,c,d,(a*0.5+b*0.25+c*0.125+d*0.0625)*10))

for i in range(40):
   ib = bin(i)
   print("8'b%s\t: begin hun = 4'd%d; ten = 4'd%d; end" % (ib[2:], i // 10, i % 10))

分割后的温度计数据传入OLED模块和串口发送模块

SSD1306 OLED模块

OLED显示模块同样引用自电子森林的应用案例及参考代码，添加了蜂鸣器播放时不更新，代码部分省略，展示修改部分

MAIN:begin
    if (oled_update) begin
        if(cnt_main >= 5'd6) cnt_main <= 5'd5;
        else cnt_main <= cnt_main + 1'b1;
    end else begin
        if(cnt_main >= 5'd4) cnt_main <= 5'd4;
        else cnt_main <= cnt_main + 1'b1;
    end
    case(cnt_main)//MAIN状态
        5'd0:begin state <= INIT; end
        5'd1:begin y_p <= 8'hb0; x_ph <= 8'h10; x_pl <= 8'h00; num <= 5'd16; char <= "Temperature:   ";state <= SCAN; end
        5'd2:begin y_p <= 8'hb1; x_ph <= 8'h10; x_pl <= 8'h00; num <= 5'd16; char <= "Time:           ";state <= SCAN; end
        5'd3:begin y_p <= 8'hb2; x_ph <= 8'h10; x_pl <= 8'h00; num <= 5'd16; char <= "This is Line 3 ";state <= SCAN; end
        5'd4:begin y_p <= 8'hb3; x_ph <= 8'h10; x_pl <= 8'h00; num <= 5'd16; char <= "This is Line 4 ";state <= SCAN; end

        5'd5:   begin y_p <= 8'hb0; x_ph <= 8'h16; x_pl <= 8'h00; num <= 5'd 4; char <={4'd0,temp_hun,4'd0,temp_ten,8'd46,4'd0,temp_unit}; state <= SCAN; end
        5'd6:begin y_p <= 8'hb1; x_ph <= 8'h15; x_pl <= 8'h00; num <= 5'd 5; char <={4'd0,time_hour_high,4'd0,time_hour_low,8'd58,4'd0,time_min_high,4'd0,time_min_low}; state <= SCAN; end
        default: state <= IDLE;
    endcase
end

时钟模块

时钟模块的思路参考了杨彧老哥的思路，在此表示感谢

时钟设定模块采用500ms检测一次按键状态，避免了按键消抖

//T=500ms分频
reg clk_500ms;
reg [10:0] clk_500ms_cnt;
always @(posedge clk_1ms or negedge rst_n) begin
    if(!rst_n) begin
        clk_500ms_cnt <= 0;
    end else if (clk_500ms_cnt <= 250) begin
        clk_500ms_cnt <= clk_500ms_cnt + 1;
    end else begin
        clk_500ms_cnt <= 0;
        clk_500ms <= ~clk_500ms;
    end
end
//时间设定
reg [3:0] hour_set_low;
reg [3:0] hour_set_high;
reg [3:0] min_set_low;
reg [3:0] min_set_high;
always @(posedge clk_500ms) begin
    if((hour_a != 0) && (hour_d != 0) && (min_a != 0) && (min_d != 0)) begin
        hour_set_high = 0;
        hour_set_low = 0;
        min_set_high = 0;
        min_set_low = 0;
    end else if(hour_a == 0) begin
        hour_set_high = time_hour_high;
        hour_set_low = time_hour_low;
        min_set_high = time_min_high;
        min_set_low = time_min_low;
        hour_set_low = hour_set_low + 1;
        if (hour_set_low == 10) begin
            hour_set_low = 0;
            hour_set_high = hour_set_high + 1;
        end
    end else if(hour_d == 0) begin
        hour_set_high = time_hour_high;
        hour_set_low = time_hour_low;
        min_set_high = time_min_high;
        min_set_low = time_min_low;    
        if (hour_set_low != 0)
            hour_set_low = hour_set_low - 1;
        else if (hour_set_high != 0) begin
            hour_set_high = hour_set_high - 1;
            hour_set_low = 9;
        end
    end else if(min_a == 0) begin
        hour_set_high = time_hour_high;
        hour_set_low = time_hour_low;
        min_set_high = time_min_high;
        min_set_low = time_min_low;
        min_set_low = min_set_low + 1;
        if (min_set_low == 10) begin
            min_set_low = 0;
            min_set_high = min_set_high + 1;
        end
    end else if(min_d == 0) begin
        hour_set_high = time_hour_high;
        hour_set_low = time_hour_low;
        min_set_high = time_min_high;
        min_set_low = time_min_low;
        if (min_set_low != 0)
            min_set_low = min_set_low - 1;
        else if (min_set_high != 0) begin
            min_set_high = min_set_high -1;
            min_set_low = 9;
        end
    end
    if((hour_set_high == 2) && (hour_set_low == 4)) begin
        hour_set_high = 0;
        hour_set_low = 0;
    end
    if(min_set_high == 6)
        min_set_high = 0;
end

走时部分，频率比设定模块更高以便正确处理时间设定。最终输出四位时间数据给OLED模块

//T=1ms分频
reg clk_1ms;
reg [12:0] clk_1ms_cnt;
always @(posedge clk or negedge rst_n) begin
   if(!rst_n) begin
       clk_1ms_cnt <= 0;
   end else if (clk_1ms_cnt <= 6000) begin
       clk_1ms_cnt <= clk_1ms_cnt + 1;
   end else begin
       clk_1ms_cnt <= 0;
       clk_1ms <= ~clk_1ms;
   end
end
//时间输出
reg [15:0] ms;
always @(posedge clk_1ms or negedge rst_n) begin
   if(!rst_n) begin
       ms = 0;
       time_min_low = 0;
       time_min_high = 0;
       time_hour_low = 0;
       time_hour_high = 0;
   end else if ((hour_set_low != 0) || (hour_set_high != 0) || (min_set_low != 0) || (min_set_high != 0)) begin
       time_hour_high = hour_set_high;
       time_hour_low = hour_set_low;
       time_min_high = min_set_high;
       time_min_low = min_set_low;
   end else begin
       if (ms < 60000)
           ms = ms + 1;
       else begin
           ms = 0;
           time_min_low = time_min_low + 1;
           if (time_min_low == 10) begin
               time_min_low = 0;
               time_min_high = time_min_high + 1;
               if (time_min_high == 6) begin
                   time_min_high = 0;
                   time_hour_low = time_hour_low + 1;
                   if (time_hour_low == 10) begin
                       time_hour_low = 0;
                       time_hour_high = time_hour_high + 1;
                   end
                   else if ((time_hour_low == 4) && (time_hour_high == 2)) begin
                       time_hour_low = 0;
                       time_hour_high = 0;
                   end
               end
           end
       end    
   end  
end

串口发送模块

刚开始使用原子哥的代码，并使用状态机进行字符串的发送，调试了半天只能成功发送一次，延时后电脑即收不到数据，遂放弃

最后还是引用了杨彧老哥的代码，进行部分修改，每秒上报温度和时间或者温度报警，一次成功，再次表示感谢。代码如下

module uart_tx(
   input           clk_in,
   input   [3:0]   temp_hun,
   input   [3:0]   temp_ten,
   input   [3:0]   temp_unit,
   input   [3:0]   time_hour_high,
   input   [3:0]   time_hour_low,
   input   [3:0]   time_min_high,
   input   [3:0]   time_min_low,

   output          uart_out
);

localparam IDLE = 2'b0;
localparam SEND = 2'b1;

reg uart_out,flag_1,flag_2,state;
reg [120:0] uart_data;
reg [7:0] tab[9:0];
reg [6:0] i;

reg clk_uart;
reg[9:0] times;
always @(posedge clk_in) begin
    if(times < 625)
        times = times+1;
    else begin
        clk_uart = ~clk_uart;
        times = 0;
    end
end

reg clk_en;
reg [23:0] clk_en_cnt;
always @(posedge clk_in) begin
   if (clk_en_cnt <= 12_000_000) begin
       clk_en_cnt = clk_en_cnt + 1;
   end else begin
       clk_en_cnt = 0;
       clk_en = ~clk_en;
   end
end
 /// @note The enter in Windows is \r\n 
 ///       while the return in macOS is \n 
always @(posedge clk_en) begin
    if ((temp_hun * 10 + temp_ten ) >= 25) begin
        uart_data = {  
            1'd1,8'd10,1'd0,                   //return
            /* 上报TempAlarm!!，代码省略 */
            1'd1,8'd84,1'd0,                   //T
            1'd1,1'd1
        };
    end else 
        uart_data = {  
              1'd1,8'd10,1'd0,                   //return
              1'd1,4'd3,time_min_low,1'd0,       //分钟低位
              1'd1,4'd3,time_min_high,1'd0,      //分钟高位
              1'd1,8'd58,1'd0,                   //:
              1'd1,4'd3,time_hour_low,1'd0,      //小时低位
              1'd1,4'd3,time_hour_high,1'd0,     //小时高位
              1'd1,8'd32,1'd0,                   //space
              1'd1,8'd67,1'd0,                   //C
              1'd1,4'd3,temp_unit,1'd0,          //one tenth
              1'd1,8'd46,1'd0,                   //point
              1'd1,4'd3,temp_ten,1'd0,           //unit
              1'd1,4'd3,temp_hun,1'd0,           //ten
              1'd1,1'd1
          };
    flag_1 = ~flag_1;
end

always @(posedge clk_uart) begin
    case(state)
        IDLE: begin
            if(flag_2 != flag_1) begin
                flag_2 = flag_1;
                state = SEND;
            end
        end
        SEND: begin
            if(i < 122) begin
                uart_out = uart_data[i];
                i = i+1;
            end else begin
                i = 0;
                state = IDLE;
            end
        end  
    endcase
end

endmodule

串口接收模块

串口接收部分引用原子哥的代码，仅修改晶振频率，在此省略

串口接收处理模块和蜂鸣器驱动模块

由于驱动蜂鸣器模块的模块只能有一个，故将整点报警也集成在内，略凌乱，代码如下

reg recv_done_d0;
reg recv_done_d1;
wire recv_done_flag;
assign recv_done_flag = (~recv_done_d1) & recv_done_d0;
always @(posedge sys_clk or negedge sys_rst_n) begin         
   if (!sys_rst_n) begin
       recv_done_d0 <= 1'b0;                                  
       recv_done_d1 <= 1'b0;
   end                                                      
   else begin                                               
       recv_done_d0 <= uart_done;                               
       recv_done_d1 <= recv_done_d0;                            
   end
end

reg clk_1s;
reg [24:0] clk_1s_cnt;
always @(posedge sys_clk or negedge sys_rst_n) begin
   if (!sys_rst_n) begin
       clk_1s <= 0;
       clk_1s_cnt <= 0;
   end else if (clk_1s_cnt >= 12_000_000) begin
       clk_1s_cnt <= 0;
       clk_1s <= ~clk_1s;
   end else begin
       clk_1s_cnt <= clk_1s_cnt + 1;
   end
end

reg [4:0] alarm_cnt;
reg clk_1s_temp;
always @(posedge sys_clk or negedge sys_rst_n) begin
   if (!sys_rst_n) begin
       tone = 0;
       alarm_cnt = 0;
       clk_1s_temp = 0;
   end else begin
       if (recv_done_flag) begin
           tone = uart_data;        //上位机中需注意此编码
       end else if ((time_min_high == 0) && (time_min_low == 0)) begin
           if (alarm_cnt <= 10) begin
               if (clk_1s_temp != clk_1s) begin
                   clk_1s_temp = clk_1s;
                   alarm_cnt = alarm_cnt + 1;
               end 
               if (clk_1s) begin
                   tone = 5'h11;
               end else begin
                   tone = 0;
               end   
           end else if (alarm_cnt <= 60)begin
               tone = 0;
               if (clk_1s_temp != clk_1s) begin
                   clk_1s_temp = clk_1s;
                   alarm_cnt = alarm_cnt + 1;
               end 
           end else begin
               alarm_cnt = 0;
           end
       end else begin
           alarm_cnt = 0;
       end
   end
end

蜂鸣器模块

蜂鸣器模块主要引用电子森林的应用案例及参考代码，修改音域为大字组到小字一组，并在播放时停止OLED的更新，修改如下

always@(tone) begin
case(tone)
           //大字组1-7
       5'h1:begin time_end =16'd45867;  oled_update = 0; end//C3,
       5'h2:begin time_end =16'd40863;  oled_update = 0; end//D3,
       5'h3:begin time_end =16'd36405;  oled_update = 0; end//E3,
       5'h4:begin time_end =16'd34362;  oled_update = 0; end//F3,
       5'h5:begin time_end =16'd30613;  oled_update = 0; end//G3,
       5'h6:begin time_end =16'd27273;  oled_update = 0; end//A3,
       5'h7:begin time_end =16'd25742;  oled_update = 0; end//B3,
           //小字组11-17
       5'h11:begin time_end =16'd22935;oled_update = 0; end//C4,
       5'h12:begin time_end =16'd20428;oled_update = 0; end//D4,
       5'h13:begin time_end =16'd18203;oled_update = 0; end//E4,
       5'h14:begin time_end =16'd17181;oled_update = 0; end//F4,
       5'h15:begin time_end =16'd15305;oled_update = 0; end//G4,
       5'h16:begin time_end =16'd13635;oled_update = 0; end//A4,
       5'h17:begin time_end =16'd12147;oled_update = 0; end//B4,
           //小字一组21-27
       5'h21:begin time_end =16'd11464;oled_update = 0; end//C5,
       5'h22:begin time_end =16'd10215;oled_update = 0; end//D5,
       5'h23:begin time_end =16'd9100;oled_update = 0; end//E5,
       5'h24:begin time_end =16'd8589;oled_update = 0; end//F5,
       5'h25:begin time_end =16'd7652;oled_update = 0; end//G5,
       5'h26:begin time_end =16'd6817;oled_update = 0; end//A5,
       5'h27:begin time_end =16'd6073;oled_update = 0; end//B5,
           //高过可听范围内频率，计为休止符
       5'h28:  begin time_end =16'd100;oled_update = 0; end
       default:begin time_end =16'd100;oled_update = 1; end
endcase
end

上位机音乐处理及串口下发

首先是制作音频。我这边使用Logic Pro，选用黄霄雲的星辰大海，使用音悦茶楼扒出来的简谱，简单地制作了一段钢琴谱，并导出成mid文件

然后使用python的mido模块解析处理mid文件，控制节奏并使用串口下发，代码如下

import serial
import re
import time
import mido
import operator

def conv_str_2_dic(str):
   res = re.search(r'note_(.*) channel=(.*) note=(.*) velocity=(.*) time=(.*)', str)
   dic = {
       'noteType': res.group(1),
       'note': int(res.group(3)),
       'time': int(res.group(5))
  }
   return dic

def conv_note_2_send(note):
   # 根据全全半全全全半列表
   # 大字组
   if note == 60:
       return 1
   # 全
   elif note == 62:
       return 2
   # 全
   elif note == 64:
       return 3
   # 半
   elif note == 65:
       return 4
   # 全
   elif note == 67:
       return 5
   # 全
   elif note == 69:
       return 6
   # 全
   elif note == 71:
       return 7
   # 半
   # 小字组和小字一组处理类似，代码省略
   else:
       return 0

def play(dic):
   if dic['noteType'] == 'on':
       hex_str = bytes.fromhex("%.2d" % conv_note_2_send(dic['note']))
       ser.write(hex_str)
   elif dic['noteType'] == 'off':
       # bpm=100 八分音符为半拍，时长为1/2/100min = 0.3s 被计作240 故延迟需除以800
       time.sleep(dic['time'] / 800)
       hex_str = bytes.fromhex("28")
       ser.write(hex_str)

def temp_alarm(ser):
   mid = mido.MidiFile("/Users/kai/Music/GarageBand/星辰大海-副歌.mid")
   for i, track in enumerate(mid.tracks):
       for msg in track[7:-1]:
           play(conv_str_2_dic(str(msg)))
   hex_str = bytes.fromhex("00")
   ser.write(hex_str)

try:
   port = "/dev/tty.usbserial-14430"  # CH340
   baudrate = 9600
   ser = serial.Serial(port=port, baudrate=baudrate, timeout=5)
   while True:
       read = ser.readline().decode("utf-8")
       print(read)
       if operator.eq(read, 'TempAlarm!!\n'):
           temp_alarm(ser)
           time.sleep(10)
except:
   print("serial port open failed!")

资源报告

FpZyMkna5XnTm-dKwgTMQTfq0V0F

感悟与心得不足之处

由于这是我第一次接触FPGA，写出来的程序必然有很多地方不是很好。模块之间的耦合性由于特殊的需求变得特别的高，有些地方为了达到任务要求充满了妥协。

心得体会

FPGA的开发与单片机裸机开发还是有许多的区别，FPGA的操作都是并行的，我认为在多任务并行方面比MCU的RTOS的伪并行效率要高上不少。

本次开发中，我也在学习蜂鸣器的使用时顺便学习了下乐理知识，作为一个工科生，我觉得乐理还是很好玩很有趣的。

小遗憾

温度传感器的温度显示一直偏高，猜测可能FPGA的热量和旁边蜂鸣器工作的热量干扰到了这个温度传感器。

蜂鸣器最高音域似乎只有C5？上到C5即破音。