Grr Roger

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11 years, 3 months ago.

No Display in Teraterm...

Hello,

I've installed the mbed USB serial program and the mbed driver shows up under "COM ports" in Win7 as "mbed serial port COM 5". (no yellow exclamations) I compiled the test program "Hello World USB" and placed the "USBSerial_HelloWorld_LPC1768.bin" file onto the mbed folder.

I've installed Teraterm 4.76 (newest) and selected serial port->mbed serial port com 5. I have rebooted the mbed device, both with the reset button and by unplugging the usb cable. However, there is nothing appearing in the terminal window.

Any suggestions as to what I could try?

Thanks!

Question relating to:

Last updated: 30 Apr 2020

4 Answers

Wim Huiskamp
11 years, 3 months ago.

There have been reports about mbed problems under Win7 caused by marginal or bad USB cables . Try another cable.

Also make sure you install the serial device driver with the mbed connected to your pc. Note that a serial driver needs to be installed for EVERY new mbed. It may not work when you have installed the driver in the past for another mbed.

You can check the connection is working by typing keys in the terminal application; nothing useful will happen, but the Status light on the mbed Microcontroller should flicker as the characters are received.

If all fails, try removing the driver and reinstalling.

Accepted Answer

Hi, Thanks again for your replies. Very mysterious....I tried the suggestion of typing my keyboard - and although I have no "receive charachter" function set up, the LED flickered. I then rebooted the mbed, and voila! The string from the mbed appeared.

Excellent! Now I can get on with the business of programming it!

Regards, GR

posted by Grr Roger 16 Jan 2013
Erik -
11 years, 3 months ago.

USBSerial is a progam that uses the LPCs USB port, not the USB connector on the mbed. If you are using the USB connector you need to just use printf.

Grr Roger
poster
11 years, 3 months ago.

Thanks for responding.

I changed the "serial.printf" to "printf", and still nothing on Teraterm.

I have looked at this page: http://mbed.org/handbook/SerialPC and tried everything there, including:

Serial pc(USBTX, USBRX); tx, rx

int main(void) { pc.baud(57600); pc.printf("I am a virtual serial port\n"); }

Tried with and without the "pc." (just printf)

Are there any particular settings? Is connecting to the "mded device" under COM ports the right way?

If not clear, I should also mention that I'm using just the single USB cable to the mbed board, no other serial or USB connectors.

Thanks!

Yoshi Mimura
11 years, 3 months ago.

Please check the serial baud rate on TeraTerm.
The default baud rate on mbed is 9600 bps.
If you set it 57600 bps, TeraTerm speed have to be matched the serial speed.

HI, Thank you. I have tried setting speed on Teraterm to various speeds such as 57600, and under the windows device drivers, together and separately, but that did not work. I tried rebooting the mbed board in between. Nothing seems to work!

posted by Grr Roger 15 Jan 2013

I am having the same issue. Were you able to figure out?

posted by Huzaifa Asif 08 May 2017