LM058 communication problem

December 5, 2008

It should not escalated to this level and since it does it a bad evidence on the ‘LM Technologies’ brand.

I am working on a system the include communication from a smartphone to a controller.
The controller support RS232, the smartphone support Bluetooth and to bridge this gap I purchased a ‘Bluetooth Serial adaptor’ from ‘LM Technologies’.

The connection works well until the device sends a string longer than 20-40 characters. Then the LM058 freezes and never recovers. (power cycle require)

I tried all known configurations, I sent question to LM support (there website support is terrible), I posted a question in related forums (and in an unrelated forums :).

At this stage it become apparent that either my device is faulty or just badly designed.

A week after my initial question to LM support I got response that suggested disabling the ‘escape character check’ using the AT command ‘ATX0‘. That indeed solve the problem.

BUT!!!
Why is this feature not documented in the LM058 user manual?? or any other related LM058 documents!!??

In the purpose of this blog I am adding a link to another adaptor manual that actually describe this feature. It seems that LM updated the LM058 adaptor functionality but not the manuals.

here it is: a little piece of information that was not part of the ‘world accumulated knowledge base’ (Internet) and now it is.
In the future I’ll try to be more informative and ‘to the point’ and less ‘blah blah’.


RIM development environment serial port

October 16, 2008

I am developing a handheld application for my company. and it on a blackberry device. basically it’s a device programmer interfacing through a serial port. since blackberrys do not have serial port I’ll be using a Bluetooth to serial port converter, but for development I can use the BB serial port emulation through the PC port.

At first I use the class connector interface to open a serial port, as they use in their samples. but I couldn’t get it to accept messages coming over the port, I spent hours on that, tweaking the port and the code, nothing. The DataInputStream.available() always return zero, although I know it got a response. Eventually I found a different class, oddly enough named Class SerialPort that worked perfectly well. RIM did advised not to use it, but I am not going to use it for the final product anyway.