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August 11, 2013 at 8:35 pm #22593
I just got my OpenSprinkler Pi, and got it all set up, but the Raspberry Pi seems to have problems when running off power from the OpenSprinkler. It’ll run fine for 5 minutes or so, and then it dies.
The PWR_LCD light on the OpenSprinkler board remains lit (green) and the PWR light on the Pi remains lit (red). But if it is connected to a monitor, the monitor loses the signal. If a USB keyboard is plugged in, it becomes unresponsive (including capslock and other lights). All network connections are dropped, and the Pi becomes unresponsive.
If I disconnect the 3-prong cable from the OpenSprinkler and use a USB power source, then the Pi runs without problems. At first I thought it might be that the OpenSprinkler wasn’t providing enough power to use a USB keyboard and the HDMI out, but I disconnected everything except the USB wifi adapter (Edimax nano USB wifi) and I still get the same behavior.
I’m using the exact same A/C adapter that appears in the video tutorial on the OpenSprinkler Pi homepage: Hunter model WT57 26VAC 750mA output.
Nothing appears in /var/log/syslog to indicate any trouble leading up to when the Pi dies.
I used a multimeter to test the voltage on the Rasperry Pi between TP1 and TP2, and I’m showing 4.8v,
Could this be a problem with my Raspberry Pi (Model B Rev 2 512MB)? Or my OpenSprinkler board (Rev 1.2)? Any ideas on how to diagnose the problem?
Thanks for any help!August 12, 2013 at 1:13 am #25317
After messing with it for a while longer, I’ve discovered that the problem does actually happen when the raspberry pi is powered by USB, it just takes quite a bit longer for it to happen. However, after several hours of trying, I haven’t been able to get the problem to happen when the opensprinkler board is disconnected.
Dumb question… the opensprinkler board comes with four support pillars for the raspberry pi board to connect to, but there are only two holes on the raspberry pi. Could the other two support pillars be shorting something out on the back side of the raspberry pi?
I also measured the voltage before and after the F3 polyfuse (as described here: http://elinux.org/R-Pi_Troubleshooting#Troubleshooting_power_problems). The difference is around 0.1v, which is well within range according to the troubleshooting guide.
I’ve ordered another raspberry pi to try to see if that resolves the issue. We’ll see how it goes.August 12, 2013 at 4:50 am #25318
Does the RPi do okay when you separate the two boards, but have the RPi powered by the OSPi board? If so, it does seem like there may be a short with the support pillars, or perhaps a faulty wire that could be losing its connection when the boards are connected.August 12, 2013 at 5:05 am #25319
The support pillars are all designed in positions that only touch solder masked regions of the Pi board. So unless if your Pi board has exposed PCB trace (i.e. broken solder mask), the pillars should not cause any shorting.
One potential issue could be the cable that comes with OSPi. A couple of months ago we had one batch of cables that had connection issues, but ever since that batch I haven’t heard any further issue with the cables.August 12, 2013 at 2:10 pm #25320
Thanks for the ideas! I ordered a new Raspberry Pi and a new 24VAC transformer. They should get here in a couple of days; I’ll post if the problem persists.
If it does, is there a way to verify if there is a problem with the OSPi cable?August 12, 2013 at 7:13 pm #25321
I tried powering the RPi from the OSPi board, but with the boards physically separated (as suggested by craigmw). The problem still happens, so it doesn’t look like it’s the support pillars.
I ran the RPi by itself overnight compiling a big codebase to see if I could trigger the problem without the OSPi board involved at all. It ran all night without problems.
I also measured the difference before and after the F3 polyfuse after the problem had occurred, but there was still a <0.1v difference, so I don't think it's that.
I got the new transformer and now voltage between TP1&TP2 when powered through the OSPi is 4.93. Before the polyfuse is 4.93, after is 4.91.
I’m pretty ignorant when it comes to electronics, but it seems like all signs point to it not being a power problem.
I’m still waiting on the new RPi that I ordered, but at this point I’m strongly suspecting a problem with the OSPi. Is there anything I can do to prove/disprove it?
Thanks again for your help!August 14, 2013 at 4:38 am #25322
What happens if you disconnect the OSPi GPIO pins from the OSPi board, but keep the power connection? If you disconnect the I/O wires but keep the smaller wire bundle for power connected, does the RPi still fail? This would at least tell you if it was a problem with the GPIO interface. Perhaps the GPIO wire bundle is shorting out somehow?August 14, 2013 at 9:24 pm #25323
Have you tried testing the wires in the gpio cable from pin to pin? I had one that had a bad wire, drove me nuts till I figured it out…August 16, 2013 at 5:10 pm #25324
New RPi got here yesterday, and has been running with the OSPi attached for 24 hours now, so it looks like the problem was actually the RPi.
I did try running the old RPi disconnected from the OSPi GPIO pins, and it worked without problems, which is why I was thinking it had to be the OSPi.
Anyway, the problem seems to be fixed for now.August 22, 2013 at 2:09 am #25325
I’ve got a pretty similar situation. Mine cuts off after several hours. Ordered a new transformer/adapter that should be in tomorrow. I’ve tried powering with the 3-wire cable plugged in and unplugged. I don’t see any difference so far. Just for safety’s sake I also ordered a new RPi. With the watering restrictions here in TX I don’t want to play around with this too much. I’ll try the other suggested tests this weekend if the power supply doesn’t work.
EDIT: I think (hope) I’m back on solid ground again with this. It appears so. Troubleshooting process (thanks to the previous posts for their suggestions):
- I did the voltage testing suggested here;
- I replaced the RPi with another one (“Oh my gosh, what will I ever do with another RPi?” 😉 ) and that didn’t solve the problem;
- I thought I would try a WiFi extender to make sure I was getting good coverage to the garage. That didn’t work;
- I re-imaged my SD card. This may have fixed it but not positive;
- I ran CAT-6 cable to the garage so I didn’t have to connect to WiFi. I think that this was the ultimate fix. The RPi/OpenSprinkler boards were running really hot with the WiPi WiFi adapter.
It was shutting down within and hour or less. It’s been running about 12 hours now. It’s running much, much cooler now.
I hope this helps someone!
EDIT 2: Wow. It’s running great now. With the help of Dan I was able to get the auto-start working.
Here’s the install in the garage: https://plus.google.com/114571878398957500272/posts/VCuXyqk7zqL
My next projects with respect to the RPi are to:
- Install a moisture sensor
- Connect to the internet to check for rain/freeze
- Install a fun selection of status lights on the board: rain, freeze, pending, sprinkling, and, heck, just some lights that say to the kids, “Lookie here, I’m cool!
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