Arduino Mega 2560能够读取0 ~ 5V的电压，并转换为10bit即0~1023级的数字信号。这怎么理解呢？
日期: 2018 年 6 月 28 日
Ubuntu 16.04软件中心安装的Arduino IDE报告错误 – avrdude: ser_open(): can't open device "/dev/ttyACM0": Permission denied
最近要使用Arduino开发一个读取电压的装置，新电脑上没有安装Arduino IDE,因此，从Ubuntu 16.04软件中心中搜索找到一个名为arduino-mhall119的软件，如下图所示：
继续阅读Ubuntu 16.04软件中心安装的Arduino IDE报告错误 – avrdude: ser_open(): can't open device "/dev/ttyACM0": Permission denied
树莓派2B使用ADS1115模块读取模拟信号
树莓派2B的GPIO不能读取模拟信号，因此需要使用一个数模转换模块来操作，这里我们研究使用
ADS1115读取模拟信号。树莓派2B启用I2C
树莓派自带I2C控制器，但是默认没有启用，我们需要手工启用，具体操作如下：
I2C is a very commonly used standard designed to allow one chip to talk to another. So, since the Raspberry Pi can talk I2C we can connect it to a variety of I2C capable chips and modules.Here are some of the Adafruit projects that make use of I2C devices and modules:
- http://learn.adafruit.com/mcp230xx-gpio-expander-on-the-raspberry-pi
- http://learn.adafruit.com/adafruit-16x2-character-lcd-plus-keypad-for-raspberry-pi
- http://learn.adafruit.com/adding-a-real-time-clock-to-raspberry-pi
- http://learn.adafruit.com/matrix-7-segment-led-backpack-with-the-raspberry-pi
- http://learn.adafruit.com/mcp4725-12-bit-dac-with-raspberry-pi
- http://learn.adafruit.com/adafruit-16-channel-servo-driver-with-raspberry-pi
- http://learn.adafruit.com/using-the-bmp085-with-raspberry-pi
The I2C bus allows multiple devices to be connected to your Raspberry Pi, each with a unique address, that can often be set by changing jumper settings on the module. It is very useful to be able to see which devices are connected to your Pi as a way of making sure everything is working.
To do this, it is worth running the following commands in the Terminal to install the i2c-tools utility.
$ sudo apt-get install -y python-smbus $ sudo apt-get install -y i2c-tools