No, there are of course other methods of verifying your implementation.
Note that there are a few separate steps that can be distinguished:
- the TEA block cipher;
- the CFB mode (using the right number of bits to forward);
- The encoding of the message and ciphertext.
First, test your block cipher (without CFB mode of operation) against any available test vectors. There seem to be a few available.
Second, test your CFB mode of encryption with a well known block cipher, e.g. DES, Triple-DES or blowfish (all come with 64 bit block size, just like TEA). You will need to establish key, IV and number of bits that are forwarded within CFB mode encryption (CFB-8 or CFB-64?).
Thirdly, test your encoding / decoding. You should treat the output of TEA as binary, not as text. For the input message you need a well described, canonical way of creating a message using numbers. Of course this encoding / decoding must be reversible. The codec should be tested separately first.
Finally, try and see if the combination of all three works as expected. If you cannot find text vectors directly then try and use a different implementation (and test that against text vectors first).
You could also use a third party implementation to create intermediate values, so you can verify the correctness of your implementation.
Here's a test vector created using Bouncy Castle (Java, v1.57) and, of course, hexadecimals to represent the bytes:
TEA in CFB-8 mode
K : 2c1003d83c3c3707a92a10f45a3bd72f
M : 3132333435363738
C : d2751754c6699453
This is the kind of representation you need to test. Note that the input message M consists of the ASCII encoding of the string "12345678". The 128 bit key and full 64 bit IV have been randomized.