I'm trying to design a circuit that can convert from a two wire full duplex (think SPI), with one transmit line and one receive line, to a one wire half duplex (think i2c), with bidirectional communication over the same line, but I'm having no luck. Is there a specific chip, or a circuit I can use?
edit: the two protocols are (de-strobed and converted to single ended) SpaceWire (or at least SpaceWire hardware carrying I2C signals) and I2C. SpaceWire uses a data in and a data out pin, so I'd like to be able to send an address or command etc. to the I2C device over the DOUT wire, and receive the data through the DIN wire. SpaceWire is a difficult protocol for interface ICs, which are either non-existant or exorbitantly priced. By 1 and 2 wire I'm excluding the clock line since it will be shared between the two protocols.