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June 27, 2014 at 1:49 pm #23005
I’m having a problem with my OSPi setup. I’ve got a version 1.2 OSPi board which had been working ok. But today I’m not getting any 24 volt output to my control valves and I’d guess that something is fried on the board. The 5 volt side appears to be working correctly – my Raspberry Pi runs fine and thinks it’s turning valves on and off. Checking the little array marked “24 V”, “+5V”, and “GND”, I’ve got a 4.87 on the 5 volt…but nothing on the 24 volt. Any ideas on how to further isolate / repair this situation?
Dave JordanJune 30, 2014 at 4:38 am #27379
4.87 volt on the 24V AC pin is clearly not right. Just to be sure: the 24V AC pin should be measured using AC voltage level on your multimeter — if you measured it as DC, the reading would not be correct.
In any case, if the 5V pin is giving you correct voltage, I think at least the power supply section is working fine. Are you not getting 24V output on any valve, or just some valves? Do you see any visible damage on the board?June 30, 2014 at 1:11 pm #27380
I’m not getting 24v output on any of the station lines. I checked all of them against ground using the AC setting on my multimeter. Also note that I’m NOT getting 4.87 on the 24 volt lines – only on the 5 volt line.
DaveJuly 2, 2014 at 12:28 pm #27381
Sorry I misread your post. When you did the voltage test, did you power the circuit from 24V AC, or did you use a USB cable to power the RPi directly? If you’ve powered it with 24V AC, that means 24V AC is present on the board, it must be that a PCB trace from the terminal block to the COM wire is broken or something.July 2, 2014 at 1:33 pm #27382
Everything was powered from the 24v, and the power to the RPi is good. It’s possible that a trace is cut somewhere, though the board had been working and I haven’t moved or remounted it.
I turned on station 1 (on the RPi) and checked the voltage on corresponding pin of the 74HC595N, thinking that I might find 5v there. But there wasn’t any voltage there. Not sure where else to look as I’m really not equipped to do detailed debugging of the board, so I guess my only real option is to buy a new one.July 2, 2014 at 1:51 pm #27383
I checked the OSPi 1.2 board, and here is the deal: the 24V pin you see is connected directly to one of the transformer pins, and it’s not even through the switch, so as soon as you plug in the transformer you should get 24V AC between the 24V pin and the GND pin. If not, you should definitely check if your multimeter is turned to AC voltage — if you measure DC voltage, you will get almost 0.July 2, 2014 at 5:20 pm #27384
Yes, I have 24v at those pins – I’m just not seeing any 24v out to the stations…July 5, 2014 at 5:35 pm #27385
It just occured to me that the problem may be due to defective terminal block: I had one user reporting to me recently that the green 2P terminal block is defective causing no voltage output. I suggest that you switch it with the Rain Sensor terminal block, which is the same type of terminal block. You can also measure the voltage at the solder joint of the COM terminal. In any case, if it’s a defective terminal block, please email [email protected] so we can send you replacements. Thanks.July 7, 2014 at 11:23 pm #27386
Got the ospi 1.4 today – have the ospi up and running. But I still wasn’t getting my valves to turn on – still no 24 volt output on those connections. The Pi-driven web page indicated that they were on…
So. I had swapped out the Raspberry Pi itself a bit ago because it seemed to just go away occasionally – I’d have to reboot it to get it running again. Not real good for a utility sort of a thing.
But that means I still have the older Raspberry Pi. So plugged the older Raspberry Pi into the ospi board and now I’ve got water.
But I have even less idea of what to look at on the Raspberry Pi than I did on the OSPi.
Oh well.July 9, 2014 at 12:29 am #27387
I have the same situation. No 24v AC output. Manually tested the stations with 24vac, so they work. The OSPi has been working fine for about a year.
Did you swap out the raspberry pi and then it started working?July 9, 2014 at 6:04 pm #27388
Yes – the combined system seems to work ok now that I’ve swapped out the Raspberry Pi.July 13, 2014 at 9:42 pm #27389
Turned out to be a faulty cable between the Pi and the OSPi board…replaced and back in business.July 15, 2014 at 5:04 pm #27390
Hmm. That seemed like it might be a possibility – the new OSPi doesn’t use the cables – the RPi plugs directly into the OSPi – so I thought maybe the cables were causing the original problem. But I checked my cables and they appear to be ok…so I’m still a bit up in the air. I may retry using the OSPi 1.2 board and the cables. I’ll post if I get any new insights.July 18, 2014 at 8:59 pm #27391
For OSPi 1.2, the cable is likely to be the problem. I suggest using a multimeter to check the pin-to-pin connection on each wire of the 8-pin cable.
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