nRF8001: interpreting logic data

[Erlend]

I'm running the ble_my_project_template example from ble-sdk-arduino, and listening to the ACI lines with a logic analyzer. Here is what I found in the first transmission, in which RDY is pulled low before REQ. One row for each byte transferred.

| MOSI | MISO | Meaning                    |
|------|------|----------------------------|
| 0    | 1    |                            |
| 15   | 4    | (len)                      |
| 180  | 129  | DeviceStartedEvent         |
| 0    | 3    | - Operating mode (standby) |
| 0    | 0    | - HW error                 |
| 1    | 2    | - Data credit available    |
|------|------|----------------------------|

I'm not sure about the first byte (MOSI=0, MISO=1). What does this mean? Secondly, I'm not sure how to interpret what the Master is transmitting (while it's really the Slave who initiated the transmission to give an asynchronous event (?)). Where in the nRF8001 PS can I find this?

[Erlend]

I would expect the first byte of MOSI to be 5, which is the length of Connect command (15).

This is the serial output:

Arduino setup
Evt Device Started: Setup
Evt Device Started: Standby
Advertising started

I'm also puzzled that Evt Device Started happens with mode = Setup. In the decoding done by Logic (with LSBit first, 8 bits per transfer, CPOL = CPHA = 0, Enable line is active low, and using RDY as enable line) there are no 129 followed by 2 that makes this possible. Decoded logic data: bpaste.net/.../252237975ab0