New Driver: PD68 "DoubleDown" - 17/20/22mm FET+4

Flashlight Modding and DIY Parts
61

I flashed the following BLF-A6 modes…

// PWM levels for the big circuit (FET or Nx7135)
#define MODESNx1 0,0,0,0,56,137,255
// PWM levels for the small circuit (1x7135)
#define MODES1x1 8,20,110,255,0,0,0

And I have 4 low modes and 0 high modes!

I am going to try to add solder to the FET pins in case they are not good.

62

I did find the solder joint problem, the PWM pin for the FET was not well soldered. Now I get both the 7135 channel and the FET channel.

Pdog, I may have to move to the firmware thread… Just was not sure about the lack of reverse thing. I thought the ground ring was quite thin as well, but it does work when mounted in a light! Right now the off time mode save is advancing 1 mode with each test and I can’t back up. Really frustrating!

I did get battcheck running, got some really odd numbers but did plug them in. Mine were higher than any other sets of files, I was using a power supply. With the unit on battery, it start stepping down almost immediately. Did not you have a problem where the numbers were off when using a power supply as well?

Tom E:
It is defined in the main BLF.c file as the tiny13.

63

Well your reversing and mode switching sound like the OTC isn’t draining. I’d try it without the lighted tailcap first. If it still behaves the same, try swapping out the OTC for a new one (and be careful how long the heat is on the cap)

64

My eyes are just shot for today! Not sure I could pull it off right now if I felt like it. I have tried it with both types of tail caps, no change. Will the hot air solder let go with hot air again and still leave usable pads?

BTW, the hole through the middle is just genius!

Matt

65

Forget my earlier post, I see the problem. You have the parts sideways. I should have marked that on the PCB. The way you have it, the BR effectively doesn’t exist, and the cap is connected to batt+ instead of batt-. And yes, you can heat it back up with the hot air and move stuff around. Did you have any problem with clearance around the small ground ring?

66

What FET is this this? I would like read about it. I didn’t see a parts list.

67

It’s basically the same parts list as any of the other fet drivers on BLF

MCU: Attiny 13a/25 or 45/85 for 20/22mm
R1: 19.1k or 22k
R2: 4.7k
C1: 10uf
OTC: 1uf
FET: LFPAK56 footprint

68

Thanks for the quick reply. With that I was able to find some and datasheets.

69

With a standard tailcap all works as expected. I do need to adjust the medium press to be shorter but it works and memory works. With a lighted tail cap memory is always previous mode! I have about 2.3k of resistors on the tailcap board, 2 5.6k resistors and a 560 on the driver. It appears that the OTC is not discharging. I assume that I may need to raise the value of the bleed resistor?

I am so close!

Matt

70

I’ve never tried to dial in the medium press with a lighted tailcap. It actually sounds like it’s discharging the OTC faster than expected. Try running TK’s offtime cap FW to get the values. Here

71

With the light tailcap the only thing not working reasonably well is that fact that mode memory always decreases 1 mode. I can go forward and backwards but just not remember the correct final mode! I do not understand the process for last mode memory. If what I understand is correct, the OTC must totally discharge to store the last mode. It seems to my simple mind that it never discharges while off and therefore considers the off time as a medium press. So, I think I have to get it to discharge more. But, I am not sure if a larger or smaller bleeder will cause that to happen or larger or smaller resistor in the tail cap. Memory works on a standard tail cap.

I see that guys have it working on the A6, maybe someone will chime in with their resistor values.

Gotta hit the rack, will work more on this one. I really like the idea.

Matt

BTW, the center hole is great. It is always hard for me to get the conductor soldered in on the center of the pad.

72

i see what you’re saying now. Maybe try posting it in the lighted tailcap thread so the others see it.

73

Is there anything you would have added to this project if you had more space?

74

Hmm… I was able to fit just about everything on the 20mm. Once development gets a little further on FW for the new mcu’s I’ll probably do some with 3 pwm channels.

75

I was thinking about board stacking for more space. I have not seen it done before, I’m not sure why.

76

I have the driver and firmware working and completed. I may add a couple more 7135’s and save this driver for my first triple in a Convoy tube light. Still have to acquire the parts, LED’s, good Noctigon board and spacers for the Convoy. This really screams well regulated medium mode triple!

So to combine notes, just in case someone else runs into any of the issues that I have.

  1. Make sure that the OTC and R1 are in the right orientation. Prevents much head banging!
  2. My build used standard FET+1 parts with a 22k resistor and a 560 ohm bleeder.
  3. I really wanted to use BLF-A6 firmware for mode reversing. I also wanted to eliminate strobe and bike flasher, figured out changes and they worked.
  4. Use offtime-cap.hex, it will save some guess work.
  5. Wanted to use the voltage to adc converter to find LVP and shutdown volts. Had to guess at the settings to some degree. My cheap bench supply must have excessive ripple or a bad wave since values were BS and way high compared to a real battery. But discharging a battery by tenths while the firmware was loaded is not going to happen. Will have to check battery during controlled discharge and adjust firmware in the future.
  6. These values in the “tk-calibration.h” file work very well with lighted and traditional tailcap.

#ifdef OFFTIM3
// The OTC value 0.5s after being disconnected from power
// (anything higher than this is a “short press”)
#define CAP_SHORT 235
//was 210, 225
// The OTC value 1.5s after being disconnected from power
// Between CAP_MED and CAP_SHORT is a “medium press”
#define CAP_MED 170
// was 170
// Below CAP_MED is a long press
#else
// The OTC value 1.0s after being disconnected from power
// Anything higher than this is a short press, lower is a long press
#define CAP_SHORT 150
#endif

7) The hole for the LED+ wire from the spring to the LED direct works great, I used 20ga wire.
And finally…
8) This really begs to be a triple! I have not built one yet, but now I will have to.

I do only really find 1 possible negative, and I will test it at a later point. I am concerned about mounting 7135’s on the battery side due to possible tab clearance issues with the driver ring in a Convoy light. But, they may go!

Thanks for reading, hope someone else tries this driver. PilotDog has designed a very well thought out board. I just wish I had those skills. I have tried the software and it makes my head hurt!

Matt

77

Thanks!

Just a note on #7, I’m 99% sure it won’t clear a convoy retaining ring with 7135’s on the back. In those instances it might work to modify the ring as others have done to fit qlite’s, or soldering to the pill may be required.

78

Just ordered 1 set of each size. Nice work, once again PD68!

Wonder if I can get an LDO on here - haven't done any research on LDO's yet though.

79

What size did you want for LDO I have one that’s 22mm

80

Ahhh - just browsed thru your OSHPark designs from your sig line. Lots of good things. Well not sure yet what sizes. Need to mod up a 7G10 - probably using a XHP70, might do a Yezl Y3 as well. Right now I know squat about an LDO - don't even have the LDO parts yet. All I know is it's needed for a 6V, 2S cell mod with an e-switch to reduce parasitic drain. Also it replaces the zener, but not sure how it's wired in exactly.

Yes, saw your 22 board: https://oshpark.com/shared_projects/CNNTJkeT, looks like v003 is your latest? Didn't realize the LDO part is so big.