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]

Now I see that when I press Reset to start everything again (as I do when I start Logic capture), I get errors in serial output:

Evt Device Started: Standby
Advertising started
Evt Device Started: Standby
HW error: 572
ll_ctrl.s0.c�⸮⸮⸮u1 ���
Advertising started
Evt Device Started: Standby
HW error: 572
ll_ctrl.s0.c�⸮⸮⸮u1 ���
Advertising started
Evt Device Started: Standby
HW error: 572
ll_ctrl.s0.c�⸮⸮⸮u1 ���

ETC

But when I restart the arduino by uploading the program it works like in the original post.