Erv's Single Cell & Simplified Color Mixing video is great, but left with a question

[Schwizzle]

Greetings all. I am doing a CF8 build (hacked/3.7V) with a RGB Tri-Cree, RICE port, recharge port, two momentary AV switches, crystal chamber, speaker. My battery is an Orbtronic 3.7V 18650 with 10 amp output.

Erv's video here: https://www.youtube.com/watch?v=ucZD7o0m-kQ, is great and basically gives me all of the wiring information I need to know. One thing that I just want to make sure I'm clear on: the way the RGB LED is wired (either way) automatically allows for FOC per the wiring diagram on page 40 of the manual, correct?

If going with the 2nd way Erv does it in the video (with the red cathode going to the main channel for regulated driving/no resistor), in order to get FoC, is it okay if the ground wires (black and green) go to inner pad vs the outer pad? Or does that even matter, i.e. using the inner pad vs the outer pad, because they are both ground points?

The only reason I am wondering about it is because in the manual on page 40, it shows the green cathode going to the outer pad of the PEX.

I'm doing as much studying and prepping as I can before I start building. Thank you all.

[Forgetful Jedi Knight]

If you’re doing the hack, they are shown going to the outer pad because it is assumed that you will be using a SMD resistor to bridge the 2 pads (which I personally have done a few times). If you are going to use “external resistors”, then yes, you can use the inner pads.

[Schwizzle]

If you’re doing the hack, they are shown going to the outer pad because it is assumed that you will be using a SMD resistor to bridge the 2 pads (which I personally have done a few times). If you are going to use “external resistors”, then yes, you can use the inner pads.

Thank you for the reply.

1. It's interesting that in the video (at 6:00), when Erv takes the Red LED to the main channel, he says you don't need any resistors at all for Blue and Green. I imagine this is because of the forward voltage being right at/so close to 3.7V, but this goes against what you mentioned concerning bridging the pads using resistors (as page 41 shows). Even with Green being right at 3.7, if it is used for FoC, a resistor would be needed for it at least correct?

2. Next to that, the drawing on page 41 says to bridge the pads, and then shows "external" resistors going to the LED. I assume that it isn't two sets of resistors being used to bridge, that in this drawing what is being used to bridge is just wire/solder and then "external" resistors are being used. Am I interpreting that correctly? I like the idea of the SMD resistors more myself (no heat shrink/space saving).

3. For FoC+Pseudo Color mixing, assuming I will put Blue and Green on the PEx pads, if I put on the appropriate resistor for each LED, that resistor will be enough to cover FoC as well, correct?

4. Pure curiosity: the + and - pads next to the TX/RX pads for RICE, what are they for? I'm on my 8th or 9th run through of the manual and I can't say I found any mention of them.

[Forgetful Jedi Knight]

I personally use nominal resistors for Blue and Green. I also know Erv’, and he usually advises to use a resistor, put people try to skirt by without it, and argue over it. You could technically get by without a resistor for Green, but it’s always “safer” (and likely cheaper) to not “push your luck”, and put a nominal resistor on both Blue and Green.

2. Correct, though I personally use the SMD resistors, just to save time and space.

3. Correct

4. They’re for the Bluetooth module as I recall. The ground was there in the past, the (+) was a recent addition.

[Schwizzle]

I personally use nominal resistors for Blue and Green. I also know Erv’, and he usually advises to use a resistor, put people try to skirt by without it, and argue over it. You could technically get by without a resistor for Green, but it’s always “safer” (and likely cheaper) to not “push your luck”, and put a nominal resistor on both Blue and Green.

2. Correct, though I personally use the SMD resistors, just to save time and space.

3. Correct

4. They’re for the Bluetooth module as I recall. The ground was there in the past, the (+) was a recent addition.

Boom. Thanks for the quick response FJK (hope using the acronym is okay ) I'm a believer in resistors as well. Also, while the NB board is "simpler" in terms of the number of joints you usually have, I must say that I much prefer the freedom of the CF8 when it comes to resistors. Will save so much space in my hilt. And it's not that much harder to understand, you just have to read the manual 5-10 times to take it all in.

And bluetooth?! Will look more into that later.