单片机解密GD32L233C-START DAC输出
单片机解密GD32L233C采用的是一款M23的内核。这个芯片据说功耗非常的低，低到什么程度呢？等后面我们再进行测试，今天我们主要来测试GD32L233C-START的DAC，既然要测试DAC，示波器是不可少的，这个实验在家做，然而LZ家里并没有示波器，不过最近看到一款好东西，LOTO，看过这款示波器的参数，还不错。所以入手了一款，测量芯片输出的DAC应该没什么问题，接下来开始测试吧。
单片机解密
首先需要输出让芯片输出DAC，单片机解密而且还需要输出波形，这个稍微费点功夫，之前在GD32L233C-START移植了RTThread，现在在这个代码的基础上添加DAC的输出程序，这个程序移植了其他网友的，代码我也贴出来，经过测试，代码没有啥问题：
比较麻烦的是正弦波的代码：
单片机解密
首先需要输出让芯片输出DAC，单片机解密而且还需要输出波形，这个稍微费点功夫，之前在GD32L233C-START移植了RTThread，现在在这个代码的基础上添加DAC的输出程序，这个程序移植了其他网友的，代码我也贴出来，经过测试，代码没有啥问题：
比较麻烦的是正弦波的代码：
const float sinus_I_quarter[91] =
{
0.0000, 0.0175, 0.0349, 0.0523, 0.0698, 0.0872, 0.1045, 0.1219, 0.1392, 0.1564, // 00 .. 09
0.1736, 0.1908, 0.2079, 0.2250, 0.2419, 0.2588, 0.2756, 0.2924, 0.3090, 0.3256, // 10 .. 19
0.3420, 0.3584, 0.3746, 0.3907, 0.4067, 0.4226, 0.4384, 0.4540, 0.4695, 0.4848, // 20 .. 29
0.5000, 0.5150, 0.5299, 0.5446, 0.5592, 0.5736, 0.5878, 0.6018, 0.6157, 0.6293, // 30 .. 39
0.6428, 0.6561, 0.6691, 0.6820, 0.6947, 0.7071, 0.7193, 0.7314, 0.7431, 0.7547, // 40 .. 49
0.7660, 0.7771, 0.7880, 0.7986, 0.8090, 0.8192, 0.8290, 0.8387, 0.8480, 0.8572, // 50 .. 59
0.8660, 0.8746, 0.8829, 0.8910, 0.8988, 0.9063, 0.9135, 0.9205, 0.9272, 0.9336, // 60 .. 69
0.9397, 0.9455, 0.9511, 0.9563, 0.9613, 0.9659, 0.9703, 0.9744, 0.9781, 0.9816, // 70 .. 79
0.9848, 0.9877, 0.9903, 0.9925, 0.9945, 0.9962, 0.9976, 0.9986, 0.9994, 0.9998, // 80 .. 89
1.0000 // 90
};
#define CIRCLE_QUARTER_1 1
#define CIRCLE_QUARTER_2 2
#define CIRCLE_QUARTER_3 3
#define CIRCLE_QUARTER_4 4
float sinus_lookup (unsigned int angle)
{
float sin_value;
unsigned int circle_quarter;
// correct angles outside the accepted angle range into 0 .. 359
if (angle > 359u)
angle = angle % 360u;
circle_quarter = 1 + (angle / 90u);
switch (circle_quarter)
{
case CIRCLE_QUARTER_1: // 00 .. 89
sin_value = sinus_I_quarter[angle];
break;
case CIRCLE_QUARTER_2: // 90 .. 179
sin_value = sinus_I_quarter[180 - angle];
break;
case CIRCLE_QUARTER_3: // 180 .. 269
sin_value = -sinus_I_quarter[angle - 180];
break;
case CIRCLE_QUARTER_4: // 270 .. 359
sin_value = -sinus_I_quarter[360 - angle];
break;
}
return sin_value;
}
void plot_sin(uint32_t f, uint32_t delta_f)
{
/* 定时周期为T=1/delta_f， f=1/(pMax*T) */
static uint32_t point = 0;
uint32_t pMAX = delta_f/f;
uint32_t value = 0;
if (point++ > pMAX) point = 0;
value = (uint32_t)((sinus_lookup(360*point/pMAX)+1)*10000)*2047/10000;
dac_software_trigger_enable();
dac_data_set(DAC_ALIGN_12B_R, value);
}
{
0.0000, 0.0175, 0.0349, 0.0523, 0.0698, 0.0872, 0.1045, 0.1219, 0.1392, 0.1564, // 00 .. 09
0.1736, 0.1908, 0.2079, 0.2250, 0.2419, 0.2588, 0.2756, 0.2924, 0.3090, 0.3256, // 10 .. 19
0.3420, 0.3584, 0.3746, 0.3907, 0.4067, 0.4226, 0.4384, 0.4540, 0.4695, 0.4848, // 20 .. 29
0.5000, 0.5150, 0.5299, 0.5446, 0.5592, 0.5736, 0.5878, 0.6018, 0.6157, 0.6293, // 30 .. 39
0.6428, 0.6561, 0.6691, 0.6820, 0.6947, 0.7071, 0.7193, 0.7314, 0.7431, 0.7547, // 40 .. 49
0.7660, 0.7771, 0.7880, 0.7986, 0.8090, 0.8192, 0.8290, 0.8387, 0.8480, 0.8572, // 50 .. 59
0.8660, 0.8746, 0.8829, 0.8910, 0.8988, 0.9063, 0.9135, 0.9205, 0.9272, 0.9336, // 60 .. 69
0.9397, 0.9455, 0.9511, 0.9563, 0.9613, 0.9659, 0.9703, 0.9744, 0.9781, 0.9816, // 70 .. 79
0.9848, 0.9877, 0.9903, 0.9925, 0.9945, 0.9962, 0.9976, 0.9986, 0.9994, 0.9998, // 80 .. 89
1.0000 // 90
};
#define CIRCLE_QUARTER_1 1
#define CIRCLE_QUARTER_2 2
#define CIRCLE_QUARTER_3 3
#define CIRCLE_QUARTER_4 4
float sinus_lookup (unsigned int angle)
{
float sin_value;
unsigned int circle_quarter;
// correct angles outside the accepted angle range into 0 .. 359
if (angle > 359u)
angle = angle % 360u;
circle_quarter = 1 + (angle / 90u);
switch (circle_quarter)
{
case CIRCLE_QUARTER_1: // 00 .. 89
sin_value = sinus_I_quarter[angle];
break;
case CIRCLE_QUARTER_2: // 90 .. 179
sin_value = sinus_I_quarter[180 - angle];
break;
case CIRCLE_QUARTER_3: // 180 .. 269
sin_value = -sinus_I_quarter[angle - 180];
break;
case CIRCLE_QUARTER_4: // 270 .. 359
sin_value = -sinus_I_quarter[360 - angle];
break;
}
return sin_value;
}
void plot_sin(uint32_t f, uint32_t delta_f)
{
/* 定时周期为T=1/delta_f， f=1/(pMax*T) */
static uint32_t point = 0;
uint32_t pMAX = delta_f/f;
uint32_t value = 0;
if (point++ > pMAX) point = 0;
value = (uint32_t)((sinus_lookup(360*point/pMAX)+1)*10000)*2047/10000;
dac_software_trigger_enable();
dac_data_set(DAC_ALIGN_12B_R, value);
}
芯片解密
