Popbloom Control with Reef-pi

[chrisebarks]

Hello @Oliver@DSunY I want more control of my Shannon S40+ using reefpi and looked at the PCB inside and noticed there are pinouts to control the lights. Can you tell me what kind of signal that I need to use to control these individual channels? I was able to use my ohm meter to find out that the voltage increased from 0 to 5v as I increased the light intensity but I want to make sure it is a dc voltage is needed and not something else.

 

[Reefing Madness]

 

[chrisebarks]

I used a battery to simulate a DC current and was getting unstable lighting on some channels so my feeling is that it is a 5v PWM. I tried an Arduino oscilloscope to see what was coming out but it didn't work too well because the program kept freezing. I will try again soon to see what's going on.

 

[oreo54]

I used a battery to simulate a DC current and was getting unstable lighting on some channels so my feeling is that it is a 5v PWM. I tried an Arduino oscilloscope to see what was coming out but it didn't work too well because the program kept freezing. I will try again soon to see what's going on.

The device can be dimmed in two ways, either by adjusting the current setting resistor, or by PWM control of the Enable pin.

Pretty sure they aren't using pot dimming

AMC7140 constant current linear regulator

Hello guys, I've bought a 10-pack of AMC7140 LED drivers to make some high power LED lamps. This regulator was recommended here on the forum a few times, e.g. by DrAzzy and Wawa. So I hope people who have used it already can answer a few questions about it. As usual, I talk too much, so this...

forum.arduino.cc

Last I knew this was the driver ic's they use:

 

[chrisebarks]

Pretty sure they aren't using pot dimming

AMC7140 constant current linear regulator

Hello guys, I've bought a 10-pack of AMC7140 LED drivers to make some high power LED lamps. This regulator was recommended here on the forum a few times, e.g. by DrAzzy and Wawa. So I hope people who have used it already can answer a few questions about it. As usual, I talk too much, so this...

forum.arduino.cc

Last I knew this was the driver ic's they use:

Thanks, this is what I see on my board so definitely not pots. The micro controller is a Holtek HT66F0042 and it looks like they even have a lead out to the pd0 pin on this chip so I may be able to just interface with it directly using the raspberry pi.

 

[oreo54]

Thanks, this is what I see on my board so definitely not pots. The micro controller is a Holtek HT66F0042 and it looks like they even have a lead out to the pd0 pin on this chip so I may be able to just interface with it directly using the raspberry pi.

Yea that's my thought.. Even just pulling the "enable" pin of the AMC7140 and running it to the PWM pinon the Aduino.
The IC doesn't list acceptable frequency nor voltage (range) of the PWM.
There is a circuit using a 555 timing chip to supply it.

 

[Oliver@DSunY]

sorry , Just see this today.


The signal is PWM.

Yes, that part can control the boards. we design this for
1, check the status of each channel.
2, test the light.

the reason why your test is “unstable lighting on some”， the IC out put PWM is conflict with your DC current.

--- I tried an Arduino oscilloscope to see what was coming out but it didn't work too well because the program kept freezing

I am a little supprise this, you should see square wave...

 

[Oliver@DSunY]

--so I may be able to just interface with it directly using the raspberry pi.

yes, just cut the connect between HT6XXX IC and 7140. there are 2 ways.
1, remove the IC
2, remove some resistence.

if you are fomilar with solder issue, I susggest remove the IC and try.
if not , I have to ask R&D for which resistances , it will cost some days.

 

[Oliver@DSunY]

Yea that's my thought.. Even just pulling the "enable" pin of the AMC7140 and running it to the PWM pinon the Aduino.
The IC doesn't list acceptable frequency nor voltage (range) of the PWM.
There is a circuit using a 555 timing chip to supply it.

Yes, you are right !

Please the power is 24V because there are 7 leds in one line (series)

 

[chrisebarks]

--so I may be able to just interface with it directly using the raspberry pi.

yes, just cut the connect between HT6XXX IC and 7140. there are 2 ways.
1, remove the IC
2, remove some resistence.

if you are fomilar with solder issue, I susggest remove the IC and try.
if not , I have to ask R&D for which resistances , it will cost some days.

Thanks Oliver,

I prefer not to remove the IC just in case so if you could ask R and D which resistances to remove it would be greatly appreciated. It also looks like there is a way to externally shut off the IC using the PB0 pin and avoid modifying the board at all, is that correct?

 

[Oliver@DSunY]

Thanks Oliver,

I prefer not to remove the IC just in case so if you could ask R and D which resistances to remove it would be greatly appreciated. It also looks like there is a way to externally shut off the IC using the PB0 pin and avoid modifying the board at all, is that correct?

Please hope this can help you .

I am very sorry that I can not do any more . it is too hard for me to understand the hardware circule.

 

[oreo54]

Interestingly convoluted on the diode side.