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Apr 9, 2010 12:57pm
Medium wwward 8 posts

Topic: Java / Seeking advice: Time-sensitive operations when writing Bug App in JVM

Backstory:  I am looking to implement an existing serial protocol decoder using the VonHippel and the Bug.  Ideally, we could accomplish this with a minimum of additional hardware, so bit-banging the pins on the VonHippel (with appropriate passive components hanging from that) would be more desirable than attaching an external microcontroller.  This also opens up the possibility for advanced software signal processing to identify issues with the serial line, perhaps using the ADC to sample the signal and provide user feedback on observed behavior if there is a fault.  An external dedicated MCU would be more difficult to code that sort of exception logic into.

Question:  When tinkering with the VonHippel module using a “blink the LED” sample app, I noticed the timing on the blinking cycles was a little variable, probably due to other processes delaying the execution of the JVM threads.  I’m aware that we’re not dealing with a real-time implementation in the JVM, but I am curious what techniques I could employ to get things to occur “fast enough” to do the work.  The serial line has a peak speed of 79 kbit/sec.  At that speed, you have about 13 microseconds per bit.  Clearly you’ll want to have windows of time long enough to encapsulate a full packet read, which is around 4,000 microseconds long according to the spec.

I have not yet looked to determine if this is feasible with the module hardware or not, but my question isn’t so much about the hardware as the programming practice – how do you write time-sensitive routines within the existing Bug JVM implementation, and if that is not feasible, how do you write them within the existing Bug software stack (native binaries,) and is there a means to offload these operations to another aspect of the Bug where execution time is more reliable?

Thanks for the advice, and the time.

@wwward

 

 

Apr 9, 2010 10:43am
User_img_not_found_03_med michele.bavaro 1 post

Topic: BUGmodules / Bespoke BUG modules

Hello,

I’m thinking of designing my own mixed signal PCB board with a GPS and Glonass front-end for navigation applications and I have a couple of questions for the BUG labs people.

a) Is the empty BUGlocation case (or any other case, even double sized) for sale, or reproducible with a resonable budget using the mechanical files?

b) What is the communication bandwidth sustainable with the USB2.0 bus? Is at least it more than 10Mbit/sec?

c) Will the interface between BUG base and BUG modules change when the BUGbase2.0 is out?

 

Thanks a lot in advance,

Michele

 

Apr 9, 2010 10:24am
Medium jconnolly 285 posts

Topic: Applications / Senior Design Project

Super cool, thanks for posting!

Apr 2, 2010 11:40am
User_img_not_found_02_med LLTDL7 2 posts

Topic: Applications / Senior Design Project

Sorry about that… I hope that this works better

ONU SeniorDesign Bug

Apr 2, 2010 10:08am
Medium jconnolly 285 posts

Topic: Applications / Senior Design Project

I’d love to have a look but it looks like our forums software b0rked your link.  Can you paste it again as a link via the little link tool in the post window?

Apr 1, 2010 3:14pm
User_img_not_found_02_med LLTDL7 2 posts

Topic: Applications / Senior Design Project

Last year, my senior design group used the Bug for our project.  We created a camera for geotagging photos as well as tagging them with the compass direction that the picture was taken.  We presented the paper we wrote about it at the ASEE North conference in 2009.  You can see our website about it here:


http://eccs.onu.edu/seniordesign/2009webpages/...


Any comments would be appreciated.


Thanks!

Apr 1, 2010 2:06pm
Medium GNUtoo 10 posts

Topic: BUGmodules / VonHippel and Keyboard

I had hardware issues like you describe too,

But it could also be something else like:

Dust,preventing the Bug module to connect properly

Bad connection,that is to say the screen is not connected/inserted properly in the bug-base

Denis.

Apr 1, 2010 12:33am
User_img_not_found_06_med tapratt 7 posts

Topic: BUGmodules / VonHippel and Keyboard

Hi Denis,

Thanks for the help.  I made those changes to my Xserver config and got the keyboard to work on slot 0 a few times.  I’m still having the same problem where I start up my bug and the bug view module doesn’t display anything but the backlight is on, sometimes I can get it to work by removing the module and plugging it back into the slot.  Other times it will display, but I can’t do anything because the touch screen won’t respond.  I checked the conierge log and syslog, but I’m not getting any error messages or anything out of the ordinary.  Kind of sounds like a hardware issue to me, but I had just returned my last bug for the same problem.  What do you think?

 

Thanks again for the help

Todd

Mar 31, 2010 3:16pm
Medium GNUtoo 10 posts

Topic: BUGmodules / VonHippel and Keyboard

hi here’s my config:

#!/bin/sh
#

. /etc/formfactor/config

# note xinit needs full server path
XSERVER=/usr/bin/Xipaq
if [ -f /usr/bin/Xfbdev ]; then
  XSERVER=/usr/bin/Xfbdev
fi
if [ -f /usr/bin/Xepson ]; then
  XSERVER=/usr/bin/Xepson
fi
if [ -f /usr/bin/Xorg ]; then
  XSERVER=/usr/bin/Xorg
fi
if [ -f /usr/bin/Xomap ]; then
  XSERVER=/usr/bin/Xomap
fi

. /etc/profile

export USER=root

ARGS=” -br -pn -hide-cursor -s 0”
ARGS=”$ARGS -mouse tslib”
#ARGS=”$ARGS vt01”

# use ucb 1×00 touchscreen if present
if [ -z ”$TSLIB_TSDEVICE” ] && [ -e /dev/touchscreen/ucb1×00 ]; then
  ARGS=”$ARGS -mouse /dev/touchscreen/ucb1×00”
fi

# use usb mouse if present
# Xorg doesn’t support ”-mouse” option, and uses /dev/input/mice automatically
if [ -z ”$TSLIB_TSDEVICE” ] && [ -e /dev/input/mice ] && [ ”$XSERVER” != “Xorg” ]; then
  ARGS=”$ARGS -mouse /dev/input/mice”
fi


ARGS=”$ARGS -screen ${DISPLAY_WIDTH_PIXELS}x${DISPLAY_HEIGHT_PIXELS}@${DISPLAY_ORIENTATION}x${DISPLAY_BPP}”

if [ ! -z ”$DISPLAY_DPI” ]; then
    ARGS=”$ARGS -dpi $DISPLAY_DPI”
fi

if [ ! -z ”$DISPLAY_SUBPIXEL_ORDER” ]; then
    ARGS=”$ARGS -rgba $DISPLAY_SUBPIXEL_ORDER”
fi

DISPLAY0=’:0’
#DISPLAY1=’:1’
TSLIB_TSDEVICE=/dev/input/bmi_lcd_ts4
exec xinit /etc/X11/Xsession—$XSERVER $DISPLAY0 -fb /dev/fb1 $ARGS $&

#TSLIB_TSDEVICE=/dev/input/bmi_lcd_ts5
#exec xinit /etc/X11/Xsession—$XSERVER $DISPLAY1 -fb /dev/fb2 $ARGS $

 

you could notice that the lines with /dev/fb1 are uncommented while the lines with /dev/fb2 are commented

That is because /dev/fb1 goes to slot0 and /dev/fb2 goes to slot1

if you wonder where /dev/fb0 goes,it goes to the bugbase small monochrome display.

Note that #ARGS=”$ARGS vt01” is also commented

Denis.

Mar 31, 2010 12:56am
User_img_not_found_06_med tapratt 7 posts

Topic: BUGmodules / VonHippel and Keyboard

Hi,

I needs some more help.  I could get the keyboard to work, but only on slot 3.  I would like to get it working on slot 0 if possible, because I plan on using the multi-function buttons along with the screen.  To get the Xserver to accept keyboard input I edited the virtual terminal arguments for the Xserver and I had to comment out one instance from starting.  Here are the last few lines of my Xserver config when it works on slot 3

#TSLIB_TSDEVICE=/dev/input/bmi_lcd_ts4 #exec xinit /etc/X11/Xsession -- $XSERVER $DISPLAY0 -fb /dev/fb1 $ARGS vt01 $*& TSLIB_TSDEVICE=/dev/input/bmi_lcd_ts5 exec xinit /etc/X11/Xsession -- $XSERVER $DISPLAY1 -fb /dev/fb2 $ARGS vt02 $*

If I uncomment both of them, then I can not get keyboard input on any slot and switching them so the first Xserver gets started doesn’t work either.

I would appreciate any help you can give.

 

Thanks in advance.

Todd

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