Dead Prop2?

[Rover]

One of my Prop2s has been running 24/7 for the last 3 weeks when I noticed it was no longer turning relays on or off.
I went out to it, removed the cover and everything looked fine, leds light on the board, etc.

I brought it indoors, plugged into my PC, and it couldn't be found when scanning the serial ports.

I then removed every connection to the pins and outs (nothing attached other than serial and 9v power... same thing.. looks fine, no burn marks no cracks.. etc but no response

I've eliminated power supply, cables, usb seriall adapters,  and ULNs( by removing them) ... as I tested with my other Prop2.. my other prop2 responded fine.

Before removing everything the Prop2 had a DS 1340 RTC, 912 MHz tranceiver, a voltage checking circuit through .01 uf cap VSS/RTC-signal pin/VDD, and 5 relays attached (30 ma each) to p OUTS)

is there anything left to try?

I'd actually like to do know what might have happened to prevent it in the future, and before I replace the prop2 with my other one (which I had plans for :(   )

[JonnyMac]

Hard to say what might of happened not seeing the controller in its environment.  Let me suggest that you disconnect everything and try again.

[Rover]

I have nothing attached to it, leds light up, but no serial com

[JonnyMac]

Well, you've done what you can -- probably have a dead board.  Can you draw a schematic of everything you have hooked to it so we can see if there's something that stands out?  I know you project worked, but there may have been something that we would recommend you do differently to prevent possible problems.

[tds234]

On another note, and not to steal the thread, but I would sure love to see the code that talks to the RTC on the prop-2 ( or is this something that Jon has already done in a N&V article somewhere?)

Doug

[Rover]

I will gen up a schematic... Jon, I know you have a corel drawing of the prop2, you mind letting me use it, I have corel and pretty good with it

as far as teh RTC... you can see the thread here http://www.efx-tek.com/php/smf/index.php?topic=448.0

[tds234]

Thanks very much, I had read that when it came through and was fascinated by it. I hadn't made the connection.

Doug

[Rover]

Here is the schematic for the system -

[Rover]

I meant to add the the following ULN pins are clipped

7,12,13,14,15 and the setup jumpers have been removed

Also there is a main spst on the Vin (upstream of diagram)

[Rover]

I'm probably posting too much on this thread but wanted you to have everything
Attached is the full blown bs2 code as it was used . I put my other prop2 into position, but I have removed the voltage check circuit

the image below is a screen shot of the vb.net app I wrote to control the prop (based on sample code found on the net for serial com in VS 2005) - just for info

[JonnyMac]

What are you doing with your voltage check circuit?  I'm a little concerned that you have it connected upstream of the filter instead of downstream, as it's going right into an I/O pin.  You have a lot of current protection there, but noise could still be an issue.

[Rover]

It monitors the supply voltage, because this a permanent installation attached to a 12V battery bank and the pump on OUT1/relay draws about 3 amps, I have the program set to shut down the OUTs if below a certain voltage level.. batteries are expensive :)   I also thought it may be on concern which is why I didn't use the voltage check circuit on my installation with the other Prop2, nothing else looked like it could affect anything.

My only other issue was setting OUTL directly from serin... I was wondering that if I had garbage come in... what would happen? I have about 120 ft from the PC to the Prop2 and no error checking , Pins 1,2,3 are relays so I don't care but 7 is the voltage check

My intention was to use the 2nd prop for some other functions and voltage checking in my power shed closer to vsupply as there is a pretty big voltage drop between it and the other one,  I even bought another tranceiver for it... bringing me to 3

On top of the my first prop2 not working .. groan... I lost my wind generator... looks like it shorted internally due to excessive rain.. been a good week :)

What are you doing with your voltage check circuit?  I'm a little concerned that you have it connected upstream of the filter instead of downstream, as it's going right into an I/O pin.  You have a lot of current protection there, but noise could still be an issue.

[menehune]

Since you are using 12volts, instead of using a voltage check on the prop, have you considered a low voltage disconnect circuit in the V+ feed to the relays?  If the battery voltage drops too low, the relays should then be disconnected, allowing the prop to continue to run.

You should be able to find them in a local auto part store
http://www.prioritystart.com/
or you could build one yourself if you want:
http://www.solorb.com/elect/solarcirc/spc3/index.html

[Rover]

I thought about that, but by having it on board the prop, I have the option of manually determining when I want to shut it down based on current voltage. Long story ... if its cloudy.. i might make a decision to shut stuff down at a higher voltage if I think I won't get enough recovery during the day, basically saving my voltage for another day.

Since you are using 12volts, instead of using a voltage check on the prop, have you considered a low voltage disconnect circuit in the V+ feed to the relays?  If the battery voltage drops too low, the relays should then be disconnected, allowing the prop to continue to run.

You should be able to find them in a local auto part store
http://www.prioritystart.com/
or you could build one yourself if you want:
http://www.solorb.com/elect/solarcirc/spc3/index.html

[JonnyMac]

I still have a bit of a concern about the connection to the external source.  The addition of the capacitor has me thinking you're worried about noise on that line.  You might consider an opto-isolator that is trimmed on the input side such that the output transistor stops conducting when the voltage is too low.