here is the LD-29 MCU pinout (eg how to put your ATtiny13A in there...)

[quote=HiTiT]
:~ strange, both of the FETs’ are rated >8A on their datasheets.
I assume that it should’nt get really hot on ~2.8A ;\/quote] I was working on measuring other stuff. Soon I’ll take a closer look at where the heat is really coming from.

I’d say that at 100% duty cycle this driver produces a good bit more than 2.8A out, although I have not measured. Probably around 3.5A+ output. The input at 8.2v (IIRC) was ~1.85A. That’s 15.17W input, so make whatever efficiency assumptions you want (80-90%) and figure the output based on that.

I dug this up just to post I found out what the black SMD component was, it’s when a SMD cap and resistor have a love child no seriously its a component called a ferrite bead.

Also my v06 boards are coming so I expect the 07’s to be a day two behind, as is usual with FT I don’t expect the driver till around middle to late August.

As far as I can tell an SMD ferrite bead would be a choke. I do not think that the component is a choke. If it was a choke I think resistance should be lower than 100k. Take a look at the DC resistance figures for some. They are ~100ohm or so and as I said in the OP this component is 100 k ohm.

My v07’s shipped yesterday!

A member here graciously sent me an extra LD-29. A good thing since mine is getting a little worse for the wear (from moving the PIC on and off, soldering wires to the pads, etc). Anyway it was ordered from FT on the 8th and arrived on the 17th with USPS - so 9 days from start to finish.

The new version LD29’s are somewhat different. I’m not yet sure what the implication of this is.

  • still uses the PIC 12F683 MCU
  • FET appears to be the same, an SO8 package 4435
  • the diode is now SBM1040.
  • an SO8 FET has been removed This missing part appears to be IR’s IRF7821.

It seems to me that IRF7821 was replaced with the tiny 8205S, but I have not looked into this closely.

SBM1040 is a 5A continuous diode in the Powermite 3 package. This package seems to be about the same size as PowerDi 5 but may be superior? I’m not sure that Powermite3 is actually superior to PowerDi5, but it’s definitely a modern high power diode so that’s good. The old diode was marked 3912 and I have no idea exactly what it was rated for. Maybe 3A, who knows. The new diode is certainly better!

The 4435 FET I assume to be a 30V P-Channel trench MOSFET. The new one is marked 4435AG and the old one was simply marked 4435.

Come to think of it, I do not see a buck controller on either the old board or the new board. There are no sanded components and nothing jumps out at me as a buck controller. Odd. I’ll have to follow the CSN trace and see where it goes from the sense resistor. I wonder if it’s going through a current sense amp and feeding directly to the PIC. If so, we need a whole new firmware :frowning:


Your new one’s from FT? My two shipped out yesterday ,I wonder which they’ll be.

I know about the good high res pic’s in the review, could you possible post a comparison shot of the two drivers physically sitting right next to each other orientated the same please?

I’m just wondering cause I’ll be ordering a PICkit3 this friday (I have 3 current projects centered around PIC MCU’s, I’ll probably be pretty much completely switching here as soon as I can and redesigning the 17dd for the 8kb PIC MCU of my choice) but is the only reason for all this to be able to program these with no additional equipment from the other AVR programming we all do? Is the MCU not able to be flashed (with the correct PIC equipment) cause its locked or something?

First of all: sorry Cereal_killer, I have no immediate plans for more photos. I’m really off of taking pictures right now. That’s why I’ve only been using my phone and only posting shots I deemed necessary. Also I don’t have a stock LD-29 available to put it next to.

That said, there’s really nothing you need to know that you can’t glean from what I wrote and the pictures I took.

I have no idea what the state of the PIC controller is.

My new one is from FT. I’m sure you’ll get the same thing, the listing on FT actually says that it’s the updated version.

I have not taken an in-depth look into the matter, but my current assumption is that the new version is just a simple refactor to make better use of space with the savings from going SO8 to SOT23-6 on that N-Channel FET.

May I ask what motivated your switch from Atmel to Microchip?

Hey man, can you post / email me the FW you have that gets the driver to run high only? I tried this (both as-is and after removing the STAR2_PIN=PB0 and references to it).

Also what way does the adapter go on? with the pin1 dot up and in the factory orientation and the 13A pin1 goes aligns with that?

Hey Cereal_killer, let me review the facts this weekend and make sure I don’t tell you a lie ;-). I haven’t worked on this in a little bit and I’m getting fuzzy myself. I have yet to install any of these PCBs (I have v6 and v7 in hand though). I just had the thing hard-wired, even worse than dead-bug style.

For now I’ll tell you what I think I know:

  • Orient the adapter PCB so that the BLF marking is against the LD-29 PCB. Orient the dot mark for Pin1 with Pin1 on the LD-29.
  • The code I linked to in the post you quoted is the last thing I messed with. IIRC I foolishly used the offtime firmware? I dunno. Definitely a bad place to start, ontime should have been used for this stage of the project - offtime is the next stage. Dumb mistake on my part, I’ll re-do it when I get back to it (this weekend?)

Somewhere in this thread I/we discuss how to turn the driver on. There appears to be both an enable pin and a PWM pin. Just pull the enable pin high or low, whatever I said earlier, and then pull the PWM pin high… that’s 100% duty cycle, a state the stock firmware never allows AFAIK. Sorry for the brevity and lack of details, I’m pretty limited on the computer front right now.

Frankly I don’t recall if the pin configuration for that firmware matches the pin configuration for the v7 adapters. I will check into this.

I have measured the PWM frequency on LOW using the new LD-29 I recently posted pictures of. I measured the period to be 76us, which should be approximately 13kHz. This isn’t visible in the output signal, but we want to be in that general range w/ the output from our ATtiny.

My scope is not in good shape, so this is questionable, but it appears that the buck section is operating at around 444kHz (XM-L2 on the output, 8v on the input, medium mode).

Align the dot with the factory orientation.

Adapter pinout on top / ATtiny side:

  1. ( 4 ) - unknown function
  2. ( 6 ) - possible offtime cap
  3. ( 3 ) - enable pin for buck circuit
  4. ( 8 ) - GND
  5. ( 5 ) - PWM out
  6. (NC) - not connected
  7. ( 7 ) - voltage divider for monitoring battery voltage
  8. ( 1 ) - Vcc
    NC (2) - unknown function

I installed an adapter board on my old-version FastTech LD-29 today. I hooked up some airwires to the adapter and successfully enabled and turned on the buck circuit, as I would without the adapter board (Of course I had to use pin8 to pull 5 & 3 high). After confirming that that worked I moved on to installing an ATtiny13A flashed with nlite.hex

All our current firmwares do PWM on pin 6, not pin 5. Also, NLITE doesn’t know to pull Pin3 high. So in order to use NLITE we must install an airwire from Pin8 to Pin3. We must also jumper Pin6 over to Pin5.

0.8A 1.3A - 3.65A-
EDIT: 0.8A - 0.25A - 1.3A - 3.65A ….apparently the star for moon mode is pulled high. No big deal, but we’ll probably need to disable any “star” functionality in firmware used on this driver.

EDIT: Apparently I forgot that NLITE features LVP. No big deal, with such a high voltage on Pin7 I doubt it will kick in. We’ll deal with LVP in upcoming firmware changes.


I will be doing this tonight man, thanks for the details.

I’ve never ran Nlite before, in the stock FW moon should be on (so the pin being grounded turns it off) or vise-versa?

Should stock on-time STAR work also?

I’m still happy to be working on this project for the good of the conunity but it sort’a feels like backwards progress for me having just received my PICkit last Friday it’s strange to be removing a PIC MCU in favor of the ATTiny lol.

Heheh, well after a closer look, the normal Star2 is PB0, or pin5. Pin5 is where we put the PWM, so that’s interesting and all ;-). For NLITE you’d normally pull Star2/PB0/Pin5 low in order to enable moon. We happen to be shorting it to PB1 which is probably low while the code initializes (before PWM starts).

I’d probably remove any extraneous inputs, such as star inputs, from the code. At least a couple of pins are pulled high by the driver for unknown reasons, plus we are shorting Pin5 and Pin6. You can compile the stock code and use it, but expect unexpected results in terms of star config.

After realizing what a pain it was to have PWM on PB0 instead of PB1 I took another look at hooking up PB1 to Pin5 of the LD-29’s landing pads. Turns out it does fit, I think, so while I’ve posted in the STAR thread for details on how to change the code, I’ll almost certainly release a v08 to allow firmwares which are closer to stock to run.

Well man [I believe] I’ve followed these instructions exactly as posted, I’ve compiled and flashed this but i get absolutly nothing, any ideas?
note I only have a new version of LD-29

Hm, not sure why its putting my writing inside your quote, strange.

What version of adapter are you using? Pin4 has no GND however grounding it with tweezers doesnt help…

Ok I know you’ve said you cant be bothered to take / post a few pic’s of your new version driver but can you PLEASE? I didnt test my driver when it came and i’ve got the adapter removed back off it and none of the PIC MCU pad’s are GND! I also notice a empty pad coming from pin8, it sits right next to it and appears to have a diode marking however the other pad of the set goes pin 4 of the to the small 6-pin component marked 8205S right below the MCU, not GND.

I’d really like to get this thing working, I have a project for it but I have so many other project’s on my plate (including all my oersonal projects as well as the 1AA boost driver I’m doing for TFF and a new AVR programmer) that I can do the stuff you figure out but I cant devote any time to actually dive in myself.

edit: good news is driver works with the PIC MCU (had to try a few different ones, I have multiple pulled 12F683’s from different drivers lol), now I’ll just wait to see what you think.
I dont need a pic anymore but could you please post a complete list of each step required to get it running all in one post?

thx

edit2: what resistors are you using to get 5A? I’ve tried every combo of resistors I have and the only thing I can do is decrease power, I wasnt able to get it any over 3A. I’ve tried from adding a second .025 all the way up to 36ohm, I also tried no resistor, just a jumper…

Let’s not get into that. I really do not appreciate any pressure from you to do unnecessary things. I’ve posted pics and markings. All you’ve gotta do is look at them.

Step one for you is to confirm that your driver works as expected without the PIC in place. As I mentioned earlier, the stock firmware never allows 100% duty cycle on the PWM/blanking/toff/whatever input for the buck circuit, so you should see 3.5-4A without doing any resistor mods. So you’ll need to do what I described in the OP:

Once you’ve done that you can move on to trying to install an ATtiny13A. For that, simply follow the explicit details I posted in #56. I haven’t done any work on the LD-29 that I haven’t posted in this thread other than the brief discussion over in the STAR firmware thread about moving PWM outputs, so the status is exactly what you see in #56. I used the v07 adapter boards. Note that after installing the adapter board and before installing the MCU I did test the driver by pulling the Enable and PWM pins high - I wasn’t really 100% sure that the adapter board would reflow the way I expected, but it seems that it did.

Not having GND is OK, don’t worry about it. I’m not sure if shorting MCU GND to BAT- is OK though, so make sure your ATtiny still works. There’s a lot of stuff going on on an LD-29, I haven’t made a circuit diagram and I have no clue how most of it actually works ;-).

The firmware you keep flashing doesn’t work - I mentioned that when I posted it.

Hey guys,

Sorry I couldn’t log in for the last 3 months.
wight, Thanks for your hard work!

I had a little time playing with my ld-29 today.
They are really seems to be a little different from the old ones.

I removed the PIC from the driver, wired it to the LED, and as expected - it didn’t work.

Then I jumpered pin1-pin3 and pin1-pin5 - still didn’t work for me.
I tried playing a little more with the jumpers, and managed to get it work on MAX with jumpers : pin1-pin2 and pin1-pin5.

  • Why could It happen? [on the OP it is still written that pin3 is the pwm]

The strange thing is that it works at about ~4A on the LED on max, which is too high for XM-L’s .

* Is there any way reducing the amp without pwm (without adding an MCU ) ?
EDIT: I could manage to lower the output to exactly 3.0A with a resistor of 0.031058ohm. now it is okay.

Another interesting question, 3 months ago I ordered “PIC to ATTINY v06”

  • will it work with an Attiny? or should I order the v07?

THANKS!! :wink: