We're trying (unsuccessfully) to attach a UART bluetooth SoC to the Raspberry Pi 3 Compute Module.
The bluetooth SoC is a based off a Nordic nRF51. It's running project Zephyr RTOS hci_uart sample. Only changes made to this sample is: pins used for comms and added a blinking LED to assure CPU is running.
What have been done so far and it works:
- on raspi-config removed the SSH over UART
- added to /boot/config.txt
dtparam=audio=off start_x=0 enable_uart=1 gpu_mem=16 - bluez 5.43 compiled from source and installed fine. Check with any of the bluez tools with
-v(also tried on bluez 5.44 with same results) - monitor the bluetooth
sudo btmon - attach bluetooth module to system
btattach -B /dev/ttyAMA0 -S 115200 -P h4 - set beacon address, power on and scan for devices
sudo btmgmt --index 0 static-addr ... something.... power on find -l - calling
hciconfigwe can see transmitted and received bytes between Pi and BT-SoC without issues.
What is missing: bluetoothctl Any attempt to use bluetoothctl informs that we have no controller.
bluetoothctl
[bluetooth]# list
[bluetooth]# agent on
Agent registered
[bluetooth]# default-agent
Default agent request successful
[bluetooth]# list
[bluetooth]# show
No default controller available
Further digging I've found that hciuart.service does not execute (as it would normally do on a Raspberry Pi 3:
pi@raspberrypi:~ $ systemctl status hciuart.service
● hciuart.service - Configure Bluetooth Modems connected by UART
Loaded: loaded (/lib/systemd/system/hciuart.service; enabled)
Active: inactive (dead)
start condition failed at Tue 2017-05-23 09:44:13 CEST; 1s ago
ConditionPathIsDirectory=/proc/device-tree/soc/gpio@7e200000/bt_pins was not met
pi@raspberrypi:~ $ cat /lib/systemd/system/hciuart.service
[Unit]
Description=Configure Bluetooth Modems connected by UART
ConditionPathIsDirectory=/proc/device-tree/soc/gpio@7e200000/bt_pins
Before=bluetooth.service
After=dev-serial1.device
[Service]
Type=forking
ExecStart=/usr/bin/btuart
[Install]
WantedBy=multi-user.target
It points that /proc/device-tree/soc/gpio@7e200000/bt_pins doesn't exist, and indeed it doesn't.
I've tried to directly execute the binary from the service and got the following error message:
pi@raspberrypi:~ $ sudo /usr/bin/btuart
Can't open serial port: No such file or directory
Can't initialize device: No such file or directory
Doing the same tests using a USB serial connection to my Linux PC it works. Bluetoothctl have controller and it sees/communicates with the BT SoC
So my questions: - Why there is not bluetooth controller? how do I add/enable one? - Is it because of the hciuart.service? How do I enable it? - Is it because of the gpio@7e200000/bt_pins? How do I add, enable them?
Thanks a lot for any help
00:00:00:00to the host computer. That madeBluetoothctlnot want to work. I managed to hack it to work by changing the "read-mac-address" function in Zephyr to always reply '11:22:33:44:55' or something like this. It was not production ready, but gave an idea on where to go. But at the end we switched to Nordic SDK API and just communicate with the PC via serial port. So I can't help you there, but hopefully gives you a direction.