go-servotester is a simple RC servo tester program on Raspberry Pi using the Go programming language.
It uses the following projects:
-
gobot (http://gobot.io/) for managing pin on Raspberry Pi platform
-
pi-blaster (https://github.com/sarfata/pi-blaster) for generating PWM in raspberry Pi
Use my fork where I modify the period to make the PWM frequency at 50Hz, which is for both analog and digital RC servo.
- libui (https://github.com/andlabs/ui) for GUI version of client program.
I run my raspi headlessly so I make this a simple client-server program. The server runs on raspi and listens on a port receving command to control the RC servo. The client program comes with a GUI or a CLI interface, sending servo position command to the server, and raspi will then set the PWM on specific pin to control the RC servo.
The project uses go module with Makefile. Simply use make to build:
make
Cross compiling for ARMv6:
GOARM=6 GOARCH=arm GOOS=linux make
Cross compiling for ARMv7:
GOARM=7 GOARCH=arm GOOS=linux make
Note: Raspberry Pi A, A+, B, B+, Zero use ARM6, and Raspberry Pi 2, 3, 4 use ARM7.
For GUI version of client program, you have to manually build it:
make build_client_gui
make install will use systemctl to add the server program on the system (raspberry pi or linux only) and start it.
make uninstall to revert it.
The server program's log file will be at /var/log/pi-servotesterd.log
You can manually run/install from bin/ of course.
Servo running on raspi, using pi-blaster period 20000000ns, listening on port 6789 (default daemon options)
./pi-servotesterd -period 20000000 -port 6789
For GUI control, run this on your desktop
./servotester_gui
For cli control, run this on your desktop with correct raspi IP and port
./servotester -addr 192.168.0.123 -port 6789
You will see:
Connecting to 192.168.0.123:6789
Servo Position>
Command format:
exit: to exit the program
12=0: set pin 12 servo position to 0% (0-100% based on 1ms~2ms endpoints)
12=23.4: set pin 12 servo position to 23.4%
12=swing: do a full range swing on pin 12
12=center: center the servo on pin 12
Latest ui lib will cause GUI program to crash once hitting 'Connect'. I have to debug this when I have time.