mbed lcd display factory

The contrast VO pin seems to have different behaviour on different displays, so you may need to experiment for your display to see anything. I think I"ve seen some work tied to 0V, some to 3.3V, or with a different resistor.

Some displays need a negative voltage at VO. One side of the trimpot is connected to the negative voltage instead of GND in that case. F.i. a Maxim MAX1044 can be used to generate the negative voltage.

The underlying HD44780 chip is a driver used in many LCD character displays. It might sometimes be referred to as Hitachi HD44780U. There are also several compatible clones of this chip in use (eg Samsung KS0066).

E Ink is the originator, pioneer and commercial leader in ePaper technology. The company delivers its advanced display products to the world"s most influential brands and manufacturers, enabling them to install extremely durable, low power displays in previously impossible or unimaginable applications and environments.

E Ink encompasses the combined E Ink Corporation, which was spun out of the MIT Media Lab in 1997 to commercialize electronic ink and EPD technology, and Prime View International, which was established in 1992 as the first TFT LCD company in Taiwan, focusing on high quality small-to-medium-sized TFT LCDs. In 2009, Prime View acquired E Ink Corporation to further integrate and expand the EPD supply chain and the new combined companies were branded as E Ink.

This Internet of Things example displays the current weather conditions on a text LCD. It uses a Google Weather API to retrieve a web page containing XML with weather data for Los Angeles. The Simple Plain XML parser library ported to mbed is used to parse the XML and retrieve the desired data fields for the LCD display. It is based on an earlier XML parser example and the Text-LCD library.

If you still get the net error message, make sure that DHCP service is enabled for your mbed. On some networks, you need to add the module"s MAC address to enable the DHCP server to give it an IP address. It times out with an error, if no IP address is returned in about fifteen seconds. If the weather does not display on the LCD after seeing "net OK", you may have DNS problems or a very slow network.

Where N/C is not connected and the top left pin of the TextLCD’s header is GND and the right most pin is D7 in the LCD orientation shown in the images above. The resistor sets the contrast and some LCDs may need a different value or a contrast adjust potentiometer. See Text LCD for additional help, if needed.

(*) Note: some older LCDs may use 5V, but 3.3V is more common on current LCDs. If you cannot find a data sheet to confirm this, try 3.3V first and if the display is still blank (after double checking all other connections and code) it might need 5V. To save jumper wires, this setup uses the four bit interface to transfer ASCII characters to the LCD.

The code sets up networking and reads a special Google web page containing XML data with weather using http.get(). Data extracted from this XML web page is then displayed in the LCD using the TextLCD library lcd.printf() function. Here is a typical web page of XML data in response to http://www.google.com/ig/api?weather=Los+Angeles

Note that the data needed is found above under -. After reading the web page and finding - , the XML parser is used in parseWeather() to extract the data fields needed for use in the LCD display. Change the city at the end of the URL to obtain weather for another city. In this code, long XML web pages from other URLs containing several thousand characters can consume all of the available RAM memory on mbed and cause out of memory errors. In such cases, file I/O could be used. Another option is to process the XML data as read streams in each block of data and release the memory buffers (to avoid running out of memory) as it is parsed in sequential order.

When the USB cable is plugged in, mbed powers up and contacts the DHCP server to get an IP address. It gets an IP address and responds with "net OK". It then reads the web page containing the XML with the current weather, parses the XML to extract the data, and displays it on the LCD.

This Internet of Things example uses mbed"s networking features to display live RSS news feeds on the LCD. It is based on earlier networking examples from the cookbook that read a web page and the Text LCD library to display characters on a text LCD. CNN Technology news is used for the live RSS feed.

If you still get the net error message, make sure that DHCP service is enabled for your mbed. On some networks, you need to add the module"s MAC address to enable the DHCP server to give it an IP address. It times out with an error, if no IP address is returned in about fifteen seconds. If the news does not display on the LCD after seeing "net OK", you may have DNS problems or a very slow network.

Where N/C is not connected and the top left pin of the TextLCD’s header is GND and the right most pin is D7 in the LCD orientation shown in the images above. The resistor sets the contrast and some LCDs may need a different value or a contrast adjust potentiometer. See Text LCD for additional help, if needed.

(*) Note: some older LCDs may use 5V, but 3.3V is more common on current LCDs. If you cannot find a data sheet to confirm this, try 3.3V first and if the display is still blank (after double checking all other connections and code) it might need 5V. To save jumper wires, this setup uses the four bit interface to transfer ASCII characters to the LCD.

A small portion of the RSS news feed web page containing XML is seen below. The data displayed on the LCD is the title. The format is "". The code uses ad hoc parsing with strstr (i.e., this searches a large string for a substring) to find the "" strings in the read buffer. The data on the web page is too large in many cases to read all of it into a memory buffer given mbeds RAM size, so it is split into several smaller buffers for each read and processed as the data streams in.

In the video above, mbed is powered up and obtains an IP address from the DHCP server. Net OK appears on the LCD. It then opens and reads a portion of the web page, searches for news items displaying them as they are found on the LCD and reads through the rest of the web page. When it reaches the end of the web page, "Read Complete" is displayed.

7. Use a Google RSS news feed. Google also has several RSS news feeds and news can be searched to generate a new RSS feed. Here is an example https://news.google.com/news/feeds?q=mbed&output=rss.

The C027 will now dial up to the internet. You will see the status “updated” in the LCD display. If the device cannot connect to the internet, it will display an error message. If there is an error message “Wrong APN setting” or “Unknown APN setting”, follow the instructions below in the section Troubleshooting.

When the device is connected to Cumulocity IoT, it will show its current status in the LCD display. The first line always displays the tenant name (until there is a message received from the platform, see the section [To interact with control operations] (#Interacting_with_the_control_operations)). The second line shows the signal quality in units of dBm. The third line displays information about which sensor data the u-blox is sending and their corresponding values. In the case of repeatedly sending similar data, the third line remains empty.

Switch to the Cockpit application using the application switcher and then navigate to Groups > where you will find the “Mbed Test Device”.

In the “Message sending” widget, enter a message in the text field, and then click Send. After several seconds, the first line of the LCD display should display the message you sent. This message will be displayed in the first line until you send another message or restart the device.

In the Configuration tab of the device, the supported configuration parameters are shown with their current values. Currently for the mbed u-blox, the only parameter is “interval” with the default value of 20 minutes, which determines the time period at which Cumulocity IoT will check the availability of the device. It must be set to the same value as in the Required interval in the Info tab.

For temperature sensor: Place one finger atop the temperature sensor, which is located in the top middle of the u-blox device, above the text “Temperature LM7580”. You should immediately see its effect on the LCD display updating its status to send a temperature reading.

For acceleration sensor: Simply turn aside or rotate the device. You should immediately see the device sending an acceleration reading on its LCD display.

For analog sensor: Turn right or left the two blue knobs below the LCD display. You should immediately see the device sending analog readings on its LCD display.

Prior to 2.1, after the LCD display shows “Join Network” and the device is correctly joined to the network, you should see “Reset Success” shown on the LCD display, which indicates a successful factory reset. Starting from version 2.1, a factory reset is much faster, simply wait for “Factory resetting” to appear on the screen, and you can release your finger. After about 2 seconds, you should see “Reset Success” on the display.

The device failed to join a network and displays “Wrong APN setting” or “Unknown APN setting”: Review the source code file C027_Support/MDMAPN.h and add an entry with the Mobile Country Code (MCC), Mobile Network Code (MNC) and your APN setting. The current MMC and MNC code should be shown on the LCD display below the error message “Wrong APN setting” or “Unknown APN setting”.

The device does not appear as CONNECTED in the device registration process: Review the application output using a serial console. See https://os.mbed.com/handbook/SerialPC for details. Also make sure you flashed the device with the correct firmware version, i.e. the one that performs the bootstrap against the correct server.

The device does not appear in the devices list in the UI: Review the application output using a serial console. See https://os.mbed.com/handbook/SerialPC for details.

Upon boot-up, the device displays “Connect to Cloud” right after “Agent Run”, instead of showing “Bootstrapping” and IMEI: The device is already registered with Cumulocity IoT under another user account, a factory reset has to be performed to unregister the device.

NXP offers a variety of evaluation and prototyping platforms that are enabled through the popular, easy to use, web-based Arm mbed development platform. With an online software development kit, free software libraries, hardware designs and online tools, it is the fastest way to create products based on Arm microcontrollers.

This is another great I2C 16x2 LCD display compatible with Gadgeteer modules from DFRobot. With limited pin resources, your project will quicly run out of resources using normal LCDs. With this I2C interface LCD module, you only need 2 lines (I2C)to display the information.If you already have I2C devices in your project, this LCD module actually cost no more resources at all. The adress can be set from 0x20-0x27. Fantastic for Arduino or gadgeteer based projects.

A quick tutorial on using the Explore Cortex M3 (LPC1768) with mbed. Right now, the USB bootloader(mass storage) option does not work with mbed. However if you have a USB to Serial converter, you can definitely program it. This tutorial also applies for other bare metal LPC1768 boards.

The mbed online compiler does not allow specifing offest addresses for RAM and ROM which are required in order to make the boot-loader work. If you"ve figured out a way let us know.

We need a hex file in order to flash it using Flash magic. Use this bin2hex utility to convert the file to hex. Copy the bin2hex.exe to some folder, copy the bin file from mbed to the same folder. Enter the command below:

It would really be nice if we were able to define offset with the mbed compiler. We will work on it and see if there is anything else we can do about it.

Using the graphic LCD from the previous tutorial, we will connect a sensor to add an interactive component to our project. We can use an MMA8452Q 3-axis accelerometer to move a ball around the screen for a cool demo.

This circuit can be made with parts in the SparkFun mbed Starter Kit. Also, keep in mind that the LPC1768 box contains a USB mini-B cable for programming and power.

To follow this experiment, you would will need the following materials if you did not order the SparkFun mbed starter kit. You may not need everything though depending on what you have. Add it to your cart, read through the guide, and adjust the cart as necessary.

Heads up! For anyone ordering the parts separately from the SparkFun mbed starter kit, you will need to solder the header to the accelerometer"s breakout board.

We will be building on the previous tutorial. In addition to importing an mbed library from the Cookbook for the LCD, we will be building our own library for the MMA8452Q accelerometer.

Click “Import this library” on the right side of the page. You will be brought to the mbed Compiler and asked to import the library. For "Target Path," select our "ulcd_accel" project and click "Import."

Repeat the same file creation process to make another file: "MMA8452Q.cpp". Your project folder should contain a main.cpp, the mbed library, the 4DGL-uLCD-SE library, and our newly created MMA8452Q library (with our blank .h and .cpp files).

And that"s it! We just created our very first library in mbed. Because the library is contained within our project, everything is automatically linked at compile time. We just need to write #include "MMA8452Q.h" in our main program to use the MMA8452Q accerlerometer functions.

Click on "main.cpp" under our "ulcd-accel" project to open up our main program file. Because we selected the "Blinky" template, there will be some code in the file already. Go ahead and delete everything in "main.cpp". Copy and paste in the following code.

Compile the program and copy the downloaded file to the mbed. Press the mbed"s restart button to see the LCD display a little red ball. Pick up the breadboard and tilt it in different directions. You should see the ball start to move around!

I2C (or "Inter-Integrated Circuit") is a communications protocol built by Philips in the 1980s. As I2C is a bus protocol, it allows for multiple masters and multiple devices to reside on the same bus and relies on addresses to communicate to specific devices. In our example, we used mbed"s I2C library to talk to the accelerometer. To read more about the history of I2C, see this Wikipedia article.

In the last tutorial, we imported an existing library. In this tutorial, we created a new library to make accessing the accelerometer easier. If you feel that you have a solid, well documented library that you want to share with others, read through mbed"s Collaboration guide and specifically, how to write and publish a library.

I have a PCB on which there is an input of 12VDC, which is reduced to 9VDC by a 3A buck converter, for supplying the Pico VSYS pin and a 7805 strung, up on the 9VDC to supply 5VDC to the 20x4 LCD display.

What was happening is, that when the backlight was switched on, the 7805 supply would drop to 3.4VDC and the LCD would stop displaying. I caught this only when I experimented with switching off the backlight. Till then, I had the backlight on from the beginning of the program...