I'm having some problems creating a EMS.

I looked at the specification and found most of the things out by
With AT+CMGS I can send the SMS. So far, so good.

I found out about the 7bit-encoding of text and how to create the UDH.
Sending a SMS: no problem.
As soon as I have a UDH, the text isn't correct when I look at the
send sms.
I made a concatenated message, so a UDH is present.

I tried to figure it out for the last 3 hours, but somehow I can't get
it to work.
The Data-Coding-Scheme doesn't seem to be the problem. I can either
set 7bit-coding or 8bit-coding. That doesn't change anything.

I looked at every single bit in my user-data ... somehow I don't get
the way the text is encoded. (just to mention again. I _do_ know how
7bit-encoding works).

If I send the text "123456" some "weired" characters are shown when I
look at the decoded sms.
But the first character is _always_ right.

The I found out, that it looks "more right" if I fill in 2 fillbits
after each 7bit-character: char1 11 char2 11.

If I try this with my text "123456" the coded message (before sending)
looks like this:
0110001 11 0110010 11 0110011 11 0110100 11 0110101
If I look at the decoded text after receiving the display shows:
"12377" ...
In binary 7bit-alphabet this would be:
0110001 0110010 0110011 0110111 0110111 0110011 0110111 1011111
1100011 1100111
If you look at the bits you see the similarity and why I added 2
fillbits ... but it's not the exact bits I send ... so the message is
only partially correct.

Does anyone know the answer?

I'm really stuck here.
Without any help I'm lost

Thanks a lot in advance.


See More: EMS-Question