5.1 KiB
5.1 KiB
Bluetooth Serial Console
Setup a cheap, simple bluetooth adapter as a serial console.
THIS IS VERY ADVANCED. YOU PROBABLY DON'T WANT TO DO THIS UNLESS YOU'RE WILLING TO PLAY WITH HARDWARE
Inspiration / Further Reading
- https://www.sparkfun.com/products/12576
- https://learn.sparkfun.com/tutorials/using-the-bluesmirf
- https://cdn.sparkfun.com/assets/1/e/e/5/d/5217b297757b7fd3748b4567.pdf
- https://www.sparkfun.com/datasheets/Wireless/Bluetooth/rn-42-ds.pdf
- https://play.google.com/store/apps/details?id=de.kai_morich.serial_bluetooth_terminal
- https://play.google.com/store/apps/details?id=com.ucconnect.ucbtadapter_hex
- https://blog.miguelgrinberg.com/post/a-cheap-bluetooth-serial-port-for-your-raspberry-pi
- https://linux-sunxi.org/Xunlong_Orange_Pi_Zero
- https://unix.stackexchange.com/questions/378359/how-to-use-uart-pins-on-orange-pi-zero
Hardware
This document assumes the Sparkfun Bluetooth Mate Silver (link) is used for the bluetooth serial console.
Android Apps
Connect to your device on the go
- https://f-droid.org/packages/ru.sash0k.bluetooth_terminal/
- https://play.google.com/store/apps/details?id=ru.sash0k.bluetooth_terminal
- https://play.google.com/store/apps/details?id=de.kai_morich.serial_bluetooth_terminal
Hardware Connection
Connect the Bluetooth Mate Silver to the Orange Pi Zero UART 1 or 2 on expansion header.
Note: use UART1 if possible. It's more likely to be present already
| BT Mate Silver Pin | UART 1 Pin | UART 2 Pin |
|---|---|---|
| CTS | N/A | 15 |
| RTS | N/A | 22 |
| Rx | 8 | 13 |
| Tx | 10 | 11 |
| VCC | 1 | 1 |
| GND | 9 | 9 |
Setup Orange Pi UART
Edit /boot/armbianEnv.txt and add uart1 to the overlays line.
Reboot after applying the changes
Configure Bluetooth Mate Silver
minicom -s
The below commands should be run to configure the Bluetooth Mate Silver. You'll need to adapt these to your needs.
$$$ # Enter command mode
V # Display firmware version
D # Displays current config
SF,1 # Restore to factory defaults
ST,0 # Disable remote configuration
SR,Z # Erase any stored addresses
SU,115K # Set BT serial speed
SA,4 # Force entering a pin code to connect
SE,1 # Turn on crypo if firmware below 5.40 (on by default otherwise)
SM,<value> # sets the mode (6 pairing)
SN,<string(max 20 chars)> # Set device name
SP,1234 # Set pin code (up to 20 alphanumeric)
SY,0000 # Set a lower antenna power mode (0 in this case, FFF4 for -12, FFF8 for -8, FFFC for -4)
S|,0A03 # Cycle on for 3 seconds and off for 10 seconds (adjust per how fiddly your bt is to connect)
R,1 # Reboot device
--- # Exit command mode
Enable New Serial tty
Start / enable a new serial tty with the following
# Adjust the default serial-getty config for the BT device/oPi
cat > /etc/systemd/system/serial-getty@ttyS1.service <<EOF
# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
[Unit]
Description=Serial Getty on %I
Documentation=man:agetty(8) man:systemd-getty-generator(8)
Documentation=http://0pointer.de/blog/projects/serial-console.html
BindsTo=dev-%i.device
After=dev-%i.device systemd-user-sessions.service plymouth-quit-wait.service
After=rc-local.service
# If additional gettys are spawned during boot then we should make
# sure that this is synchronized before getty.target, even though
# getty.target didn't actually pull it in.
Before=getty.target
IgnoreOnIsolate=yes
[Service]
ExecStart=-/sbin/agetty 115200 %I $TERM
Type=idle
Restart=always
UtmpIdentifier=%I
TTYPath=/dev/%I
TTYReset=yes
TTYVHangup=no
KillMode=process
IgnoreSIGPIPE=no
SendSIGHUP=no
[Install]
WantedBy=getty.target
EOF
ln -s /etc/systemd/system/serial-getty@ttyS1.service /etc/systemd/system/getty.target.wants
systemctl start serial-getty@ttyS1
systemctl enable serial-getty@ttyS1