beagleboneblack

问题 I followed this answer to enable PWM on my Beaglebone Black, but I wasn't sure if that method is using the PRU to do hardware PWM or if it's toggling the pin in software? I see other references to /sys/class/pwm/ehrpwm (e.g. here) which I'm more confident is hardware PWM, but I'm not sure how to enable that interface. To summarize how I'm enabling PWM: echo am33xx_pwm > /sys/devices/bone_capemgr.9/slots echo cape-universal > /sys/devices/bone_capemgr.9/slots config-pin P8.13 pwm echo 6 > /sys

问题 Since the device I am developing has physical buttons, I do not want to see a navigation bar taking up my screen space. Rowboat-android on Beagleboneblack shows the navigation bar by default. Where do I turn it off? EDIT: I am not developing applications. I am developing a Beaglebone based device. I want to remove the bar globally from the system. Somewhere there should be a code or setting in the Android source. 回答1: Found the answer at Building a wireless Android device using BeagleBone

问题 Note: the selected answer is the original one that solved the problem, for more details refer to the additional one below. I'm not able to configure SPI0 on my BeagleBone Green Wireless (BBGW). I'm trying to achieve this without using overlays, only pure DeviceTree. /dev/spidev1.0 and /dev/spidev1.1 are there, but any I/O returns garbage. Oscilloscope connected to SCLK displays mostly noise, here are pictures (each in different time scale). Important parts of my .dts/.dtsi: &am33xx_pinmux {

问题 We are creating a runnable java jar to run on a beagle bone black(running ubuntu). We have created a runnable jar which runs fine on our mac and pc(windows) but will not run on the ubuntu system. We keep getting the following error when running: Exception in thread "main" java.lang.reflect.InvocationTargetException at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect

问题 I'm attempting to figure out how to get a USB Bluetooth dongle to work with my BeagleBone Black. I've tried a few different ones to no avail, but have seen posts from others who seem to have had some success. I have tried the procedure documented here: http://www.michaelhleonard.com/enable-bluetooth-on-beaglebone-black/ However, when I plug the dongle in, it doesn't even light up. Nor does it show up when I "lsusb". The BBB is being powered by a 2.5A 5V adapter, so power should not be an

问题 SIOCGIFADDR = 0x8915 def getIpAddr(iface = 'eth0'): ifreq = struct.pack('16sH14s', iface, socket.AF_INET, '\x00'*14) try: res = fcntl.ioctl(sock, SIOCGIFADDR, ifreq) except: return None ip = struct.unpack('16sH2x4s8x', res)[2] return socket.inet_ntoa(ip) At each step what are the return values of the functions? And, what is SIOCGIFADDR? Also, why [2] has been used following the unpack() function? 回答1: SIOCGIFADDR : is stands for get internet interface address means 'eth0'. This is CPU macro

问题 I'm currently stuck on a problem with GPIO pins with the Beaglebone black. I am looking for a proper way to read the values from GPIO pin p8_4 in C. I tried to use a library which used an old not supported way from the time before device tree's where introduced, if I understand this correctly. I tried to find other solutions to my problem but I can't seem to find one. Is there anyone who can get me on the right track in C? 回答1: Here is a C code: #include <stdio.h> int main() { FILE *io,*iodir

问题 I downloaded and installed JDK8u33 for ARM on my beaglebone black, and according to this documentation (http://docs.oracle.com/javase/8/embedded/jdk-arm-8u6/index.html) javafx is included and supported. However, I can not find jfxrt.jar anywhere in the JRE or JDK, and using javac on a simple javafx program yields "javafx.application" is not a package. What gives? 回答1: As @eckig says, since the 8u33 for ARM version, Oracle has removed JavaFX from the ARM distribution. To run any JavaFX

问题 I have searched & googled a lot but I cannot get this to work. I want the Beaglebone to boot up into my Qt application. However, what I get is that the GUI boots up OK but then in a few seconds the Angstrom login screen overwrites my GUI, which stays running in the background. I set up a systemd service as follows in /etc/systemd/system: #!/bin/sh [Unit] Description=Meta Systemd script [Service] USER=root WorkingDirectory=/home/root ExecStart=/bin/sh -c 'source /etc/profile ; /home/root/meta6

问题 I'm working with a BeagleBone Black and using Adafruit's IO Python library. Wrote a simple quadrature decoding function and it works perfectly fine when the motor runs at about 1800 RPM. But when the motor runs at higher speeds, the code starts missing some of the interrupts and the encoder counts start to accumulate errors. Do you guys have any suggestions as to how I can make the code more efficient or if there are functions which can cycle the interrupts at a higher frequency. Thanks, Kel