Serial port for Canon X-07

Canon X-07 is great little handheld retro computer. But being Canon, nothin is standard. Canon has always insisted using weird proprietary connector for devices, and usually it is impossible to find connectors that would fit them. This is also a case with X-07. It uses weird connectors for serial- and parallel ports. They look bit like a normal D-sub connector, and D-sub connector almost fits into them, but it is not a good fit. I wanted to make new connector that matches X-07’s serial port perfectly, so I took my callipers and 3D cad and started to work. Read More …

UART to RS232 voltage level shifter

IMG_3577Sometimes I find myself in need of interface some old tech that uses legacy RS232 interface. The thing is today’s computers and other smart logics do not have real TIA-232 compliant serial ports. The RS232 standard uses voltage levels that range from ±3V to ±15V, and space between -3V and +3V is defined as not valid. And a logic 1 is transmitted as negative voltage.

Even though use of RS232 ports are seldom use anymore, an asynchronous serial communication is not dead. Many embedded systems use it as debug interface. Also some devices still use it as communication interface, even if physical layer is implemented with USB or Bluetooth.  Read More …