Joan, I will definitely try your proposed solution. TheRayTracer, I did investigate difference between .xfer() and .xfer2() in documentation, but in practice these command do the same, if the one try to send array of commands (I checked it on oscilloscope). Btw, this has been already reported a few ...

I have SPI slave device connected to my RaspberryPi 1 (revison "000e", model B, manufactured by Sony, SPI IC family = BCM2708, implementation BCM2835). My device vendor suggest to interface the device in this way: first send command byte (0x03), wait for at least 10mS and then send data byte (0x04)....