MCU PWM

[doobedoobedo]

It's off the breadboard - and in a badly made mod!

This board has a hardware bug - pulling the reset down to ground instead of up to 5V 


But a through hole resistor and some judicious soldering of two components fixed it

Now it's in a quickly put together mod thing
What I'm vaping at


What I could be doing:



What I originally wanted to do:

(yes that's temp control)

The problem with the temp control was simply too much power. It takes a duty cycle of 16 to get reliable readings and as the wick dries it just produces too much heat, so I've had to drop it .

Still working bugs out of the firmware.

[Breaktru]

Nice work doobe 

[doobedoobedo]

  I don't think I could have done it without the help of the people on this forum.

It can run off of either a 2S or 3S battery. The max wattage is adjustable in the settings menu. It takes the max output of the battery (either capacity * C rating, or a user set amp limit) at 10V for 3S or 6.6V for 2S - the low voltage cutoff points. So you can have a consistent vape throughout the voltage range even if you're a high power nutter. I have a 1000mAh 45C 3S LiPo attached so 450W max. Most parameters are adjustable in the settings menu.

It also automatically adjusts the max and min watts you can set according to the resistance of the coil and the state of charge. I currently have a .7 ohm coil so I can adjust between 12 and 184W - what it's actually capable of giving me, the maximum will drop a bit as the battery depletes as will the minimum.

Pretty much all the bugs have been squashed now and I'm just finishing off the settings menu. I've just got some boards with the hardware bug fixed too, so I'll be making myself something much nicer to put it in .

[charming]

Amazing project you have created. Wow! very impressive indeed 

[Ian444]

Well done, I like the auto min/max watts feature, good thinking there.

Can I ask what type of voltage regulator you are using for the mcu, and what size of input/output caps for the reg?
Just asking since I need to put a reg on my simple displayless mcu pwm project I was working on.

I was even thinking of using a TL431 shunt reg for its fast speed and simplicity.

[doobedoobedo]

The voltage regulator for the MCU is basically the arduino pro-mini reference design. (https://www.arduino.cc/en/uploads/Main/Arduino-Pro-Mini-schematic.pdf)

I'm using an LTC2050 to amplify the voltage across the shunt.

[Ian444]

Thanks. I went to download the MIC5205 datasheet and see that I already have it, and can get it locally, cheap too. Since its working for you I guess its good to go (never heard of it before). Real nice project you built there

[Visus]

Awesum
450 Watts will put and take hair off the chest

 

Definitely needs a custom 3d doobe box

It's amazing how looking for high power mods it was impossible to find or source over 50 watt small sized mod chips at a time a few weeks back without intense search now theres 1k watt mods in hobbyland and they were always there...