Otherwise, the board is OK. But it takes a lot of research on the internet to get his way, because there is no datatsheet on this map. The datasheet of TC35 can nevertheless find at Siemens, and note differences in multimeter or oscilloscope, including pin "TX" (which is an input pin!) Is raised to + 5V (not +2.64 V!) with a rather weak pull-up resistor (about 500 ohms).
The coating beneath the TC35 itself is too fragile. I had to do it again because a serial connection line had finally connect to the mass of TC35 (vicious failure, the hitch in the varnish was hidden under the TC35 ...)
