Looking at the nRF8001 DK User Manual: http://imgur.com/a/NyY0L
It is unclear how pins 2-10 are organized.
Looking at the nRF8001 DK User Manual: http://imgur.com/a/NyY0L
It is unclear how pins 2-10 are organized.
Ok, if there are no objections, I will get a TXB0108 then. Thanks. Edit: This is for ACI, so I need 3 high-to-low conversions and 2 2 low-to-high. Someone said that although TXB0108 is bidirectional, all channels have same direction at a time. But low-to-high should not need any translation (right?). Hence I could use that board for the high-to-low conversions, and have no low-to-high conversion. Sounds okay?
You will have to check the datasheet of your device to see what is the MIN input voltage for logic high. It seems the Arduino UNO support high inputs from 3-5 V, while the nRF8001 datasheet specifies output high voltage at VDD-0.3 V, leaving you at the edge of the specifications if running without level shifting on your low-to-high lines if VDD of nRF8001 is 3.3 V.
Someone told me that 5V would be fine for prototyping. However I have another problem now; I think I must have wired it wrongly. Because RDY is held low (one spike during setup) - and when the master (Arduino) sets REQ to low, only MISO goes to high (according to my wiring). http://i.imgur.com/0PbGAMo.jpg I assumed that the lower-right pin in P1 is pin 1, because of the printed '1'. So the RDY pin is left, and next to the topmost one. Is this wrong?
Yes, your understanding of the pins are correct.