I have a weight scale with display TM1627 datasheet chipset. I want intercept and decode signal with arduino and write value to tx port.
The TM1627 device appears to be driven in display mode as a shift register. It has the classic Clock, Strobe and Data_in pins. Start by looking for rising edges of the clock pulses, print out the status of the data_in pin (0 or 1 ) and print a marker when the strobe pin changes state. You will see a bit stream which represents the status of all the digit segments. From that, you can determine what was last written to the display.