Which board revision are you building? You shouldn’t need two 10uF caps but I haven’t tried just one on wight’s board. I use RMM’s boards (from his MTN store) and you only place one 10uF.
The 36k resistor isn’t required if you already have a 22k. It just gives you more options with the ADC calculation for the LVP (low voltage protection). With the 22k and 2S (~8.4V) you end up being in the upper range of the ADC (limit of 255) with 6V LVP. If you wanted to have something higher for your LVP like 6.4V you would need the 36k resistor. You can see the calculations on RMM’s Google sheet that he so nicely shared with us before:
If you look, the 36k brings the ADC values more into the middle rather than the upper limit.
Does anyone happen to know what could be causing one of these drivers to change modes on its own?
I made 50 of these last batch and they all work fine normally. I had even used one of them with an eswitch in the past and it was fine. However recently I tried using JohnnyCs dual switch firmware with them and this is what I get.
https://youtu.be/vw5rxIBh7_M
It will just sit there and skip upward in modes at random on its own. I tried multiple drivers and even assembled a brand new one and the result is exactly the same. I tried both 6 and 12v configs too with no luck.
I tried using the default firmware from JC and TomEs eswitch one and they both skipped. I had used toms before too and did not have this issue so the only thing I can think is that I was shipped a bad batch of components. Problem is I have no idea which part could cause this :(
Hhmm. I watched the video 3X, not sure wut could be goin on. It seems very periodic and relatively slow, I think... What kind of setup to you have there? Think I saw 4 cells in series, so 16V going into the driver? Wow... With an e-switch, I assume you are using an LDO?
The pace seems like LVP is kicking in, but it's going up not down... But if it's acting like a click is happening, I suspect something unreliable bout the switch input, but you are grounding it manually. Dunno, I'm no expert there in electronics. Maybe the voltage the MCUU is getting? If so, maybe the LDO that supposed to regulate that voltage? Again, I'm not sure exactly how an LDO works, but it's supposed to deliver the correct voltage to the MCU. Maybe you can check that voltage level on the MCU VCC pin #8?
By dirty VCC you mean like a trace that is too close to something else? By circuit setup you just mean a picture of the underlying traces right? If so I will try to do that tomorrow.
I also have one other pressing question if you don't mind.
I have tried to use firmware that has a strobe function with these drivers, and on both the 1 and 2 cell board the strobe and SOS sequences are very very slow. I have tried 2 different firmware's which I know to be good with 7135 boards and the result is the same.
When you're pulling high amps with an FET you can make the MCU glitch if the layout and components aren't just right.
About the SOS speed: there is no reason why the speed would be different on an FET driver than it would be on any other driver with the same MCU. Are you sure that you're flashing the same file and fuses?
Ya the firmware is the same and I tried it on like 5 boards. I know for sure the code is good to, its my Sport UI from DrJones.
I may pick up a few boards from you and try installing my components on that and see what happens. If all my problems go away then we will know where to look for the trouble.
I have been wondering if some drivers are too sensitive to RFI — it’s hard to test.
And with WiFi there’s plenty of radio noise around.
With the lens opening and wires from LED exposed there that could act like short little antennas, could electronic smog be a problem?
I’ve taken some dubious lights (LDCH-20 and LDCH-30 drivers with 1xNiMH) on long walks to see if their behavior jumping modes was any different.
Couldn’t really tell.
Thanks!