An extra driver channel for aux LED?

I have built a Convoy S2+ triple using Mtn’s triple DTP MCPCB. Interestingly it also has space for 3x XQ-E emitters. It would be useful if I can have my triple SST-20 as main illumination and triple red XQ-E for preserving night vision/ low light usage. I’m not sure what driver has two separate output channels, i.e. a driver that can drive the white main LED and the red aux LED separately. Does this type of drivers exist? Any suggestions will be greatly appreciated.

See these two posts:

S2+ white / red (and then this other one a few posts down on the same light)

and then this S2+ white / UV

Those are surely some nice builds! So what I have to do is isolate a single 7135 from the driver (would a random one do, or it has to be a specific one?)and bridge the Attiny13A pin 5 with the 7135 pin? (And what pin is it on the 7135?) Does this drive the red emitter using only 1 7135 chip? And the driver firmware probably needs some modifications to it, or does the stock BLF A6 firmware works just fine? It seems like the current MTN17DDm in my S2+ won’t be able to achieve this kinda of output. Oops, I hope I won’t be asking too much questions. :nerd_face:

Hey CK that is sweet. I need to check out that thread more.

Most sense would make a driver that has already 3 channels, mod the modegroups in Atmel studio of the n 7135 channel for red
You could likely drive those with 3-5AMCs

I’m not good at electronics, in short does that mean that I isolate all the 7135s in that channel the same way? And what specific code in the firmware has to be modified?

no if you look on Texas Ace or my designs you need only to drill out the viases connecting top and bottom side, as its basically a FET+1 driver with added AMCs on the spring side
then drill a hole from bottom side to to where it does not hurt anything between 2 AMCs and connect a wire to the AMC leg

I modified one driver that way for a BLF member

From my understanding that means the regulated mode of the driver could then be used in a separate (set of) emitter(s) and the FET/”DD” mode can be used with the main LED (s)?

yes and if you change the code for modegroups you can place red with different brightness levels in the mode order where you want

I see, I’ve just started trying to compile hex files but I don’t succeed everytime. For example I don’t really know how to “assign I/O pins” when I was trying to compile a .hex file from TK’s Cresendo .c file. I followed Hoop’s guide on how to flash firmware and Comfychair’s guide on converting a .c file into a .hex file. I believe that using the newer Atmel Studio 7 doesn’t differ from the Atmel Studio 5.1 in Hoop’s guide?

Look into the CWF dragon driver.

If you make some changes in the circuit you can flash my FW on standard BLF A6 driver to control 2 separate channels

Sorry if I’m getting repetitive here, by “standard” do you mean a BLF A6 driver with the 7135 chip isolated, as I’m not sure which pin of the 7135 has to be connected to which pin of the MCU.

BLF A6 driver unmodded is a bad choice for multi emitter lights the voltage spikes make the MCU reset on turbo
and you would loose moonlight on main LED

I currently have a MTN17DDm that is also FET+1, perhaps to keep the moonlight on the main LED while being able to power aux LEDs, I have to resort to getting a dual/ triple channel driver thay is intended for such uses?

Edit: Actually the lowest mode on a multiple 7135-based driver is also acceptable for me. I think that’s an easier option as they are cheap and easy to source.

pins 5 and 6 are the one connected to PWM, my FW requires removing the 7135 from the pcb an connect one more FET/7135 to the same pin but to connect it to the other LED.

You can add more channels with FET/7135 but with no PWM so only DD or n*350mA

What kind of mod can prevent these spikes?

the FW does not make a driver

oshpark board with separated bottom AMCs and added pad