Difference between revisions of "Matrix - Analog to Digital Converter"
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[[Matrix - Analog to Digital Converter/zh|查看中文]] | [[Matrix - Analog to Digital Converter/zh|查看中文]] | ||
| − | == | + | ==Introduction== |
[[File:ADC.png|thumb|Analog to Digital Converter]] | [[File:ADC.png|thumb|Analog to Digital Converter]] | ||
| − | + | We utilize the PFC8591T in this module and extend necessary pins through a 2.54 mm spacing pin header. The PFC8591T is an 8-bit A/D and D/A converter. It has 4 A/D channels and 1 D/A channel. In this module we use the PFC8591T's power, ground, I2C, A/D and D/A pins. The I2C's address is configured as 1001000x. Its power source range is 2.5V - 6.0V. By default the power pin is 5V however if you want to take a 0 - 3.3V analog signal and keep its accuracy you can connect it to a 3.3V power source. | |
| − | We | + | |
==特性== | ==特性== | ||
Revision as of 10:01, 5 August 2015
1 Introduction
We utilize the PFC8591T in this module and extend necessary pins through a 2.54 mm spacing pin header. The PFC8591T is an 8-bit A/D and D/A converter. It has 4 A/D channels and 1 D/A channel. In this module we use the PFC8591T's power, ground, I2C, A/D and D/A pins. The I2C's address is configured as 1001000x. Its power source range is 2.5V - 6.0V. By default the power pin is 5V however if you want to take a 0 - 3.3V analog signal and keep its accuracy you can connect it to a 3.3V power source.
2 特性
- 宽电源电压输入，2.5V-6.0V
- I2C接口，3.3V/5V
- 8-bit A/D x4
- 8-bit D/A x1
- 体积小巧， 带固定孔，方便嵌入到外壳
- 2.54mm排针接口，接线方便，通用性强
3 使用方法
3.1 连接
- 连接到Tiny4412 SDK (1506)
- VCC接5V，G接地
- SDA接I2C SDA
- SCL接I2C SCL
3.2 Linux下的C示例
#include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> #include "libfahw.h" int main(int argc, char ** argv) { int devFD; int data, channel, mode; if ((devFD = pcf8591Init()) == -1) { printf("Fail to init pcf8591\n"); return -1; } if (pcf8591SetCtrl(devFD, PCF8591_INIT_AD_CONTROL) == -1) { printf("Fail to Set pcf8591 control AD\n"); pcf8591DeInit(devFD); return -1; } mode = 0; printf("pcf8591 working as AD in mode%d\n",mode); for(channel = PCF8591_AIN_CHANNEL0;channel <= PCF8591_AIN_CHANNEL3; channel++) { data = pcf8591Read(devFD, mode, channel); printf("Channel%d's value: %d\n",channel,data); } pcf8591DeInit(devFD); return 0; }
3.3 编译并运行示例
git clone http://github.com/friendlyarm/fa-hardware.git cd fa-hardware cd demo/matrix-analog_to_digital_converter make
将编译生成的pcf8591通过ftp上传到开发板上运行即可测试。
