显示加速度和磁力传感器值实时曲线，附VB源码

Frdm307 · 发表于 2015-12-3 15:36:16

本帖最后由 Frdm307 于 2015-12-3 15:40 编辑

第一次帖子，弄得不好的地方，小编多包涵。发这个帖子的原因主要有2个
1.看了@wambob 的文章：https://www.nxpic.org.cn/module/forum/forum.php?mod=viewthread&tid=599763&highlight=frdm-k64
下载了mbed中的 Hello_FXOS8700Q 例程，觉得不太过瘾，没有曲线，不够直观
2.想把上位机串口读数据和绘制实时曲线的方法和大家分享一下，共同学习，基于直观的实时曲线，促使大家对FXOS8700CQ传感器开发一些有趣的应用
基于FRDM-K64F板子，我所做的工作有2个部分，如下：
1. Hello_FXOS8700Q 例程中，printf语句太多，main.cpp修改如下：

#include "mbed.h"
#include "FXOS8700Q.h"
//FXOS8700Q acc( A4, A5, FXOS8700CQ_SLAVE_ADDR0); // Proper Ports and I2C address for Freescale Multi Axis shield
//FXOS8700Q mag( A4, A5, FXOS8700CQ_SLAVE_ADDR0); // Proper Ports and I2C address for Freescale Multi Axis shield
FXOS8700Q_acc acc( PTE25, PTE24, FXOS8700CQ_SLAVE_ADDR1); // Proper Ports and I2C Address for K64F Freedom board
FXOS8700Q_mag mag( PTE25, PTE24, FXOS8700CQ_SLAVE_ADDR1); // Proper Ports and I2C Address for K64F Freedom board
Serial pc(USBTX, USBRX);
MotionSensorDataUnits mag_data;
MotionSensorDataUnits acc_data;
MotionSensorDataCounts mag_raw;
MotionSensorDataCounts acc_raw;
int main() {
float faX, faY, faZ;
float fmX, fmY, fmZ;
int16_t raX, raY, raZ;
int16_t rmX, rmY, rmZ;
acc.enable();
//pc.printf("\r\n\nFXOS8700Q Who Am I= %X\r\n", acc.whoAmI());
while (true) {/*
acc.getAxis(acc_data);
mag.getAxis(mag_data);
pc.printf("ACC: X=%1.4f Y=%1.4f Z=%1.4f ", acc_data.x, acc_data.y, acc_data.z);
pc.printf("MAG: X=%4.1f Y=%4.1f Z=%4.1f\r\n", mag_data.x, mag_data.y, mag_data.z);
acc.getX(&faX);
acc.getY(&faY);
acc.getZ(&faZ);
mag.getX(&fmX);
mag.getY(&fmY);
mag.getZ(&fmZ);
pc.printf("ACC: X=%1.4f Y=%1.4f Z=%1.4f ", faX, faY, faZ);
pc.printf("MAG: X=%4.1f Y=%4.1f Z=%4.1f\r\n", fmX, fmY, fmZ);
acc.getAxis(acc_raw);
mag.getAxis(mag_raw);
pc.printf("ACC: X=%d Y=%d Z=%d ", acc_raw.x, acc_raw.y, acc_raw.z);
pc.printf("MAG: X=%d Y=%d Z=%d\r\n", mag_raw.x, mag_raw.y, mag_raw.z);*/
acc.getX(&raX);
acc.getY(&raY);
acc.getZ(&raZ);
mag.getX(&rmX);
mag.getY(&rmY);
mag.getZ(&rmZ);
pc.printf("FF ACC: X=%d Y=%d Z=%d MAG: X=%d Y=%d Z=%d EE", raX, raY, raZ,rmX, rmY, rmZ);
wait(0.5);
}
}

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我只保留了一句printf，用于从串口输出ACC和MAG，为了确保串口接收字符串的完整性，我用FF和EE来识别整串字符串。
2.上位机用VB编写，MSCOMM串口控件。代码关键点介绍如下：

Private Sub DrawACCMAG(x As Single, y As Single, z As Single)
Dim wd As Integer
Dim maxv As Integer
maxv = 5000
If OptMag.Value Then
maxv = 3000
End If
wd = 30
'确保不会超过最大值，ACC设为-5000 5000,MAG设为-3000 3000
x = IIf(x > maxv, maxv, x) '[-maxv maxv]
y = IIf(y > maxv, maxv, y)
z = IIf(z > maxv, maxv, z)
x = IIf(x < -maxv, -maxv, x)
y = IIf(y < -maxv, -maxv, y)
z = IIf(z < -maxv, -maxv, z)
xpos = xpos + wd
'新点位置尚未到达图框边缘，则顺序往后画线条
If xpos <= Pic2.ScaleWidth Then
Pic2.PSet (xpos - wd, PreYpos_x), vbRed
PreYpos_x = x + maxv
Pic2.Line -(xpos, PreYpos_x), vbRed
Pic2.PSet (xpos - wd, PreYpos_y), vbGreen
PreYpos_y = y + Max
Pic2.Line -(xpos, PreYpos_y), vbGreen
Pic2.PSet (xpos - wd, PreYpos_z), vbBlue
PreYpos_z = z + maxv
Pic2.Line -(xpos, PreYpos_z), vbBlue
Else
'新点位值已到达图框边缘，则往前移动一帧，并将新点画到图框最后
Pic1.PaintPicture Pic2.Image, 0, 0, Pic1.ScaleWidth, Pic1.ScaleHeight, 0, 0, Pic1.ScaleWidth, Pic1.ScaleHeight '复制pic2
Pic2.PaintPicture Pic1.Image, 0, 0, Pic1.ScaleWidth - wd, Pic1.ScaleHeight, wd, 0, Pic1.ScaleWidth - wd, Pic1.ScaleHeight 'pic2左移30
Pic1.PaintPicture Pic3.Image, 0, 0, Pic1.ScaleWidth, Pic1.ScaleHeight, 0, 0, Pic1.ScaleWidth, Pic1.ScaleHeight ' pic1 去line
Pic1.PSet (0, PreYpos_x), vbRed
PreYpos_x = x + maxv
Pic1.Line -(wd, PreYpos_x), vbRed
Pic1.PSet (0, PreYpos_y), vbGreen
PreYpos_y = y + maxv
Pic1.Line -(wd, PreYpos_y), vbGreen
Pic1.PSet (0, PreYpos_z), vbBlue
PreYpos_z = z + maxv
Pic1.Line -(wd, PreYpos_z), vbBlue
Pic2.PaintPicture Pic1.Image, Pic2.ScaleWidth - wd, 0, wd, Pic2.ScaleHeight, 0, 0, wd, Pic1.ScaleHeight
End If
End Sub

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主要思路是采用PaintPicture 方法，对pic2进行剪切移动，实现实时曲线的效果（类似任务管理器中的实时曲线）

'====================================================================================
' 文本接收
'====================================================================================
Private Sub textReceive()
Dim str As String
Dim ffpos, eepos As Integer
On Error GoTo Err
InputSignal = MSComm1.Input
Text1.Text = Text1.Text & InputSignal
ffpos = InStr(1, Text1.Text, "FF")
If ffpos <> 0 Then eepos = InStr(ffpos, Text1.Text, "EE")
If ffpos > 0 And eepos > 0 Then
MSComm1.RThreshold = 0
str = Mid(Text1.Text, ffpos, eepos + 2)
GetPointsFormstr str'用FF EE截取完整字符串送给数值提取函数
Text1.Text = ""
End If
Err:
End Sub

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效果与应用截图：

串口曲线1

之前我也一直对于FRDM-K64的串口使用迷惑，后来发现只要安装了最新的mbed驱动，插到opensda口插入USB后自己会虚拟一个串口，上位机配置成这个串口号即可收到printf语句发送的字符。和我之前对串口的理解很不一样，之前我都是用虚拟串口助手将2个串口对接，而这货居然可以自己发自己收。附上mbed最新驱动。
串口曲线2.jpg