The device defaults to an inactive state (no auto conversions) unless reconfigured.
So I write to the MAX31856 config register 0x80 to setup the device to automatically read the default K type thermocouple using an 8-bit transfer 0X80 address followed by 0x80 data. CS line goes low and immediately before and after the transfer. The timing of CS low to the first clock rising edge is 200 nsec (I have tried 400nsec)
It appears to not accept the config data sent as the DRDY line never changes state after sending this data.
To verify the config data was correctly loaded I attempt a read of the config register by de-asserting CS and reasserting and then send address (0x00) followed by 0x00 to read the data, but the SDO line of the IC remains in a high impedance state (no pull-up used and the pin voltage not driven high or low).
Can't seem to figure out what I am not understanding - this is not my first time with SPI.
Anyone sees my error?