Not sure if this has been discussed before nor if it will work.
The Attiny MCU used on Nanjg 105c has 5 usable pins. Leave the PB2 for battery level detection. Let PB1 to drive one 7135 (disconnect all other 7135 from this pin). Use PB0 to drive 2 7135s. Use PB3 to drive 3 7135s and use PB4 to drive 2 7135s. So the 4 pins drive all 8 7135s.
So for low or moon modes use PB1 to drive the 7135 by using PWM, up to 100% - 350 ma. For 50, turn on PB0 and PB4 (no PWM). For 100, turn on PB1, PB0, PB3, and PB4 all at the same time.
Yes, this has been brought up before, I do not remember how it ended. Yes, it would be more efficient in the lower modes, and have a few PWM-less steps. Feel free to do a little forum searching, and if you can’t find what you are looking for, go ahead and build it yourself!
So I could take a 105c and with a bit of creative soldering connect a 7135 to one of the stars and reprogram the driver to PWM that line for moonlight? I might have to get the programing tools.
Yes, it would definitely need to be reflashed with suitable firmware. None of the drivers comes with any way to control the other (potential) output pins, they only use pin #6. The others are either not used or used as inputs (from the stars). It would need custom firmware to change those input pins to outputs.
I sort of, theoretically at least, worked out a way to do this with the attiny13 grafted onto the gen1 DQG tiny 26650's boost driver. It uses no PWM on any of the outputs, each output pin is either on or off and each pin has its own small FET and resistor. Outputs are used only one at a time, and the level for each mode is set by the resistor value on that 'channel'. Wight wrote a pre-alpha firmware for it but I have yet to assemble & test it. It's definitely possible to do with that particular mix of hardware, though.
The now-discontinued Flex Asgard driver also used individually addressable 7135s, though it uses a different MCU.
ATtiny 25 or a PIC would be better suited for that, alot more suitable, l as larger flash space, I think the PIC does internal volt check, so no resistor bridge needed (more driver space for 7135’s)
Wasn't Tido the first to use that kind of setup? One pin with one AMC and PWM, then 1*AMC, 2*AMC,4*AMC on other pins without PWM; a level of 20% could then be achieved by 1*AMC full and the PWM-AMC at 60%, gives 12.5%+60%*12.5%=20%.
I used some creative cutting and soldering to have 4 independent channels of 2*AMC each with software-PWM on a NANJG105C for my first RGBW driver (for my newer ones I designed a PCB to avoid that).
I mentioned in passing a long while ago that I wanted to do this multiple pin thing, and did eventually get around to building a driver for my D4 tube light that worked well and I liked a lot.
My theory was(is) that LED’s are more efficient at lower currents, and also better regulation is achieved using constant current rather than pwm’ing down from a high current.
So I modified Tido’s firmware to PWM three 7135’s, giving me moonlight, low, medium and a normal high at 1amp, three fast clicks turned on pin 3 which were wired to seven more 7135’s giving a hidden turbo mode.
Unfortunately after dozens of drops on to concrete floors the wire to the emitter pulled off the PCB and blew the driver, to get it going I chucked in a single mode 1Amp driver but I miss the original.
Thanks for all the responses. I may want to try this using a Nanjg 105c (when time allows it). And try to code for it. Seems like a lot of work :weary: .
I found a data sheet for 7135’s that are available in as low as 120 mA output does anyone know of a source of 7135’s other than the 350 mA and 380 mA ones?
Actually, it is just binary, so you can do better than I said. The PWM is the part after the binary point. For the integer part, the number of 7135s should double at each pin.
Assuming no other considerations!
This is the maximum control with limited control data, if all 7135s are equal.
Personally I think there’s little point in controlling individual 7135’s it’s easier to have three or four and PWM down to the level required, plus tint shift is avoided.
Here’s a old pick of the mod, pin 6 control three 7135’s on the front and pin 3 controls the one at top right then through a via to six more on the back for turbo.
