Looking for some help on picking a microcontroller.

So, I am working on a project that runs 100-120 LEDs in parallel. I would like to be able to use a little programming to add effects. For example, i would like to use pwm to make them fade on, when i power on the device. I tried doing this with an attiny85, but that maxes out at 40ma of current. so even a test string of 10 LEDs was way too dim. I need a microcontroller that is programmable and can handle 2 amps of current. I have an arduino uno and am familiar with a few different attiny chips. But, i'm not afraid to pickup a different development board. I'd also like the microcontroller to be able to comfortably fit inside of a round tube with an internal diameter of .75" to 1". all suggestions, or microcontrollers to read up on are welcomed.

Thanks, Derek

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Former Member over 9 years ago in reply to artful_bodger +1

Thank you. i actually had a 10 year old emachine running linux die the other day. it was a weak computer i used only for coding arduino. I actually planned on taking it apart for the psu today. I'll look…

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Robert Peter Oakes over 9 years ago

You need something like this to help with how to drive the LEDs

Driving BIG loads with your micro controller - no isolation
Drive BIG things with added safety. OPTO Isolators
Sense BIG things with your Launchpad or Arduino, OPTO Isolated inputs.

You can get cheep boost cnvertors that will up the voltage to a sufficient level to drive the led strings

You say you dont have the room but as 10 strings of 10, you only needing to add 10 resistors

If you want to control the LEDs individually or as groups then you will have to do something like this anyway or use NeoPixels (To use the Adafruit name for them) which are 5V multicolour (RGB) leds that are serially adddressable, you hook them all up in series for the power and one data line to the AT Tiny

What supply are you using
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Former Member over 9 years ago in reply to Robert Peter Oakes

for prototyping i'm using the 5v line of an arduino uno. but i plan to use a 3.7 lipo battery in the final product. and all the LED's are soldered into one long string. they look kind of like a ladder. they are going into a tube just a little bit wider than the LED ladder. I could add 10 resistors. but there is no way to separate the LED string and make it look nice. I want one solid structure going up the tube. So i'm doing 1 chain of 100 LED's in parallel.
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peterjcs23 over 9 years ago in reply to Former Member

an interesting bit of product design, the circuit has to fit your requirement! Use an overrated insulated mosfet to switch with PWM and if the handle can be metal use it as the heat sink. Let us know how you get on!

Peter
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peterjcs23 over 9 years ago in reply to Former Member

an interesting bit of product design, the circuit has to fit your requirement! Use an overrated insulated mosfet to switch with PWM and if the handle can be metal use it as the heat sink. Let us know how you get on!

Peter
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