These days, connecting your microcontroller project to a WiFi network is pretty easy — you connect up an ESP8266 to your microcontroller project and pretend it’s a WiFi modem, using these old-school-style AT commands. But what do you do if you need to flash new code into the microcontroller? You can’t reprogram the micro remotely through the ESP8266 because those stupid AT commands get in the way.
How to create a virtual serial port. COM Port, serial to ethernet, virtual serial port; September 26, 2017. If your device supports wifi, click the + sign the expanded information will reveal the unit’s current IP address. Otherwise, it should be listed on the main line of the device entry. In the figure below the SB800EX shows an IP of 10. Virtual Serial Port Driver PRO enables the connection of multiple physical ports to one virtual port. A switcher function ensures your application is provided with a free serial port while seemingly connected to a single port.
Virtual Serial Port Windows 10
The solution? By flashing the esp-link firmware into your ESP8266, you talk directly to the microcontroller over WiFi as if it were connected by a serial cable: the ESP8266 becomes a totally transparent WiFi-serial bridge. Now, with a serial bootloader and an ESP8266 in Wifi-to-serial bridge mode, you can reflash your microcontroller wirelessly, and then telnet in to interact with and debug the system remotely. Once you’ve fixed the bugs, you can re-flash the microcontroller: all over WiFi, without having to climb up a ladder to reach your IoT attic-temperature sensor.
To flash a connected Arduino, for instance, all you need to do is convince AVRDUDE to use the network instead of a locally-connected USB-serial cable:
avrdude -p m328p -c arduino -b 115200 -P net:192.168.1.123:23 -U:yourHexFile.hex
. The ESP8266 passes the data straight through its TX and RX lines to your microcontroller and everything works as if it were wired.Configuration to allow the ESP8266 to join your WiFi network takes place on a self-hosted webpage that uses [Sprite_tm]’s esp-httpd standalone server, which makes setup pretty painless. And then after that you can simply telnet to the ESP8266 at port 23 and type away, or do anything else you would with a wired serial connection.
Although the simple bridge mode came first, esp-link looks like it’s growing to be a one-stop shop for all your IoT or microcontroller + WiFi needs. In addition to the serial bridge code, there is also a REST-based microcontroller-to-internet mode and there is bi-directional MQTT support in the wings. We haven’t had a chance to dig into these yet, so if you have, let us know in the comments.
If you want to dig in deeper, head over to [Jeelabs]’ blog for a slightly outdated tour of the project written by the code’s author, [Thorsten von Eicken]. For the most up-to-date development news, follow the very active development of esp-link in this thread on the esp8266 forums.
You can add virtual parallel (LPT) ports and virtual serial (COM) ports to a virtual machine. A Workstation virtual machine can use up to three parallel ports and up to four virtual serial ports.
Beer lambert law definition pdf. Beer-Lambert Law. • The Beer-Lambert Law • The intensity of light decreases exponentially with depth in the material • Linear attenuation coefficient µusually expressed in units of cm−1. • µis a function of wavelength µ=µ(λ) – So Beer-Lambert Law is also a function of λ, i.e.
■ | Linux 2.6.x kernels that support parallel ports use the modprobe modulename and modprobe parport_pc modules. Workstation requires that the parallel port PC-style hardware option (CONFIG_PARPORT_PC) is built and loaded as a kernel module. |
Some Linux distributions do not grant a virtual machine access to the lp and parport devices by default. If this is the case on your Linux host system, you must add the VMware user to the group that has permission to access those devices. | |
A parallel port on the host system does not have an Extended Control Register (ECR). | |
■ | You can add up to four serial (COM) ports to a virtual machine. Virtual serial ports can output to physical serial ports, files, or named pipes. |
■ | You can increase the speed of a serial connection over a pipe to a virtual machine. |