July 5, 2014 at 12:09 am #23025
I’m having some trouble getting enough voltage between the solenoid pins. If I measure the initial voltage between COM and station 1, 2, or 3, they are all around 3.5V. (I haven’t tried 4-8). When I turn on station 1 from the web interface, the voltage jumps to around 18V on station 1 and 2, and around 11V on station 3. The voltage fluctuates a little. Turning on station 2 or 3 has no effect on the voltages observed.
A few things I’ve tried:
– The SD card image is the one on your website, with only changes to the /etc/network/interfaces file for adding wifi.
– The raspberry pi seems happy, is serving http traffic, etc.
– I’ve removed the screw terminals and directly clipped to the pins on the board using alligator clips, so it can’t be a loose screw terminal.
– I am using A/C mode on my multimeter.
– I’ve also tried attaching a solenoid to COM/station 1 and it doesn’t see enough voltage to engage. I tried directly hooking up my power supply to the solenoid and it does engage, so the solenoid is good.
Any thoughts on how I might debug further?July 5, 2014 at 6:51 pm #27442
What’s the power supply you are using? Can you check the label and see the output voltage and current rating? Also, I assume you are running Dan’s interval program, is that right? If you are running Rich’s sprinklers_pi program, you may need to change a few parameters / settings first.July 6, 2014 at 4:23 am #27443
The power supply is an standard orbit 24VAC 740mA supply that I picked up at Lowes. With no load, I see ~27-28V at the leads with a multimeter. This is Dan’s interval program which starts itself up on port 8080 using the stock flashed card software.July 6, 2014 at 8:34 pm #27444
I tried again today and now I’m just seeing 4V on terminal 1, no matter which I turn on in the software.July 10, 2014 at 5:47 pm #27445
Well I can’t think of any obvious reason. All OSPi boards have been tested using real sprinkler solenoids and verified to function correctly. I suggest you send an email to [email protected] to arrange for an exchange so we can check that’s going on with the board.March 8, 2018 at 4:29 pm #49308
A few years later….. but I have exactly the same problem.
Around 3.5V DC output. Did you ever get a resolution?April 1, 2018 at 8:58 pm #49461
Interestingly, I am starting to have an issue that I think might be related.
Just recently, my sprinklers are failing to start, after a couple of years with no issues. I bought my OpenSprinkler PI back on May 11 2015. The PI itself has no issues, it hums along and runs Dan’s web gui. I am able to SSH in, and run all kinds of commands.
However, If I trigger a zone, I can hear the value start to open and water flow, but within a second it closes and the water flow stops. I tried reseating the white COM wire, but didn’t seem to make a difference.
I don’t think it is an issue with the solenoids, because the same thing happens with every zone I try and trigger. Also, if I manual turn the solenoid on, it stays on.
Could the power supply have gone bad? Mine was also purchased at Lowes a few years back.April 28, 2018 at 9:13 am #49722
I have a similar problem. The solenoid opens but then there is not enough voltage to keep it open. The output voltage on start is 24VAC, then it goes rapidly down to 6,5VAC. This is not sufficient.
I’m wondering if it is a power supply issue (Output 24VAC, 1500mA – not sufficient power) or if there is the possibility to change the power output parameters in the software, increasing the transient duration or increasing the 6,5 to something like 9VAC.May 17, 2018 at 7:10 am #50017
If your power supply is rated 24VAC, 1500mA, it’s more than sufficient to drive the OSPI, RPi and solenoid valves. If you find that the voltage drops to 6.5VAC when the solenoid opens, you should check if the solenoid may have a shorting somewhere. That’s the only reason I can think of that causes the output voltage to drop that much. Measure the resistance between the two wires of the solenoid — typical 24VAC solenoids should have resistance between 20 to 50ohm.May 17, 2018 at 7:15 am #50023
Problem solved differently. I connected the solenoid valves, to see if they opened, directly to the power supply and let them open and close several times: it was just some dirt in the water pipes…
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