Reef Pi, on a wish and a prayer!

[Ranjib]

here are a couple of screen shots of my configuration

Set all channels to 50% intensity and take voltage reading across all the juntions, i.e. at the pins of pca9685, then at the input pins of ULN2803, then at the output pin of the ULN2803 and then finally at the connector... what readings you are getting?

 

[Michael Lane]

Also, do the LEDs on the doser light up at all?

 

[PaulJ2303]

i'm assuming you want me to measure from these points to ground?
the pins on the PCA9685 from the ULN2803 are at 0v the VCC pin is at 5.06v, both the sca and the sda pins are at 3.59v.
the output pins of the ULN2803 (the pins that connect directly to the DP3s) to ground all measure 12v ... apart from the fourth one which is 10v (ive wired it up and it's connected to an output on the board inside the DP3s but doesn't have a pump connected to it)
the input pins of the ULN2803 (the pins that connect to the PCA9685) to ground all measure 0v
at the RJ connector the 2 outer power lines both measure 12v to ground, the signal lines all measure 2.9v

no the LED's dont light up ... also ive tried the trick @AquaRaider44 used to test the actual pumps by touching the output of the ULN2803 to ground and the pumps do run at full speed but the led's dont light up.

 

[PaulJ2303]

a close up of the wiring i'm not sure it was clear before:

 

[AquaRaider44]

i'm assuming you want me to measure from these points to ground?
the pins on the PCA9685 from the ULN2803 are at 0v the VCC pin is at 5.06v, both the sca and the sda pins are at 3.59v.
the output pins of the ULN2803 (the pins that connect directly to the DP3s) to ground all measure 12v ... apart from the fourth one which is 10v (ive wired it up and it's connected to an output on the board inside the DP3s but doesn't have a pump connected to it)
the input pins of the ULN2803 (the pins that connect to the PCA9685) to ground all measure 0v
at the RJ connector the 2 outer power lines both measure 12v to ground, the signal lines all measure 2.9v

no the LED's dont light up ... also ive tried the trick @AquaRaider44 used to test the actual pumps by touching the output of the ULN2803 to ground and the pumps do run at full speed but the led's dont light up.

Odd because my pumps light up fine. Maybe check my build tread and double check your wireing

 

[PaulJ2303]

Odd because my pumps light up fine. Maybe check my build tread and double check your wireing

thanks for the reply I've followed your build thread with interest.
yes i must have done something stupid .. it's just finding out what lol.

 

[Michael Lane]

I'm having some trouble understanding the readings you are describing. This is what I would expect if you have the channels set to 50%.

 

[PaulJ2303]

Cheers Michael .. i'll recheck it all and get back to you.

 

[PaulJ2303]

well I've been banging my head against this pca board .. well not literally but hey. i cant find any shorts or anomalies so as I've reached the end of my knowledge I've decided to get one of @Michael Lane excellent Goby boards.

ML reef-pi hat goby by ML Reefkeeping on Tindie

ML reef-pi breakout hat for aquariums (goby)

www.tindie.com

for me it's the perfect choice as it enables me to get a state of the art (IMO) reef controller up and running with all the joy of a self build but without all the angst and confusion.

I'll let you know how I get on!

 

[Urtoo]

Paul, can you take a picture of the underside of that board you are using?
I see no solder in it. It looks like a blank board with holes that was not tinned...

 

[PaulJ2303]

I see where your going with this, I'll try to re solder the joints when i get a chance. good idea.

 

[PaulJ2303]

In the end i went with the Goby hat made by @Michael Lane .....

OMG it still didn't work, time to panic. i checked and checked all to no avail so i went right back to the start and reinstalled raspbian and reef pi .... it turned out i hadn't got I2c enabled in the raspberry pi so i was simply not getting any signal ... the motors were never going to turn

anyway all's well now. phew!

 

[Urtoo]

Doh!
but now it’s fixed. Looking forward to adding one to my config, if I get time to work on it that is. dang work taking my reef time from me.

 

[Ranjib]

Nice :0), progress finally

 

[PaulJ2303]

Doh!
but now it’s fixed. Looking forward to adding one to my config, if I get time to work on it that is. dang work taking my reef time from me.

Good luck, I'm finding the whole thing massively rewarding and adding dosing pumps to my tank can only make it better and more stable.