- Tue May 12, 2020 4:18 am
#215162
Basically my question is, what is the maximum number of PWM outputs on the Artemis Nano I can use, if I want 10ma from each to drive LEDs, and also a single i2c bus for a breakout board. I'm hoping to get 16 of the 17 total pwm outputs, and use the two remaining GPIOs for i2c, if I can. I will probably have to use the GPIOs from the Qwicc connector. The 3.3v regulator is meant to have a maximum current of 300ma, so I'm hoping I can source 160ma from the GPIO at once for LEDs.
Explanation:
For my project, I need at least 24 PWM outputs to power LEDs , to drive 3 of the Dual 7-Segment Display - LED (RGB) (https://www.sparkfun.com/products/13999).
I am going to use the SparkFun 16 Output I/O Expander Breakout (https://www.sparkfun.com/products/13601) to give me this plus more. But I later found out that this breakout is optimized for current-sink driving of LEDs, not current-source which I need because of the way the LEDs are multiplexed. This is a slight problem because the max output of this breakout is 8ma per pin and I need 10ma for the red LEDs. Correct me if I'm wrong, but I'm going to use MOSFETs to switch this slightly larger amount of current. I want to solder the least amount of MOSFETs possible, so I want to use as many of the PWM outputs on my microcontroller instead.
Thanks!
Explanation:
For my project, I need at least 24 PWM outputs to power LEDs , to drive 3 of the Dual 7-Segment Display - LED (RGB) (https://www.sparkfun.com/products/13999).
I am going to use the SparkFun 16 Output I/O Expander Breakout (https://www.sparkfun.com/products/13601) to give me this plus more. But I later found out that this breakout is optimized for current-sink driving of LEDs, not current-source which I need because of the way the LEDs are multiplexed. This is a slight problem because the max output of this breakout is 8ma per pin and I need 10ma for the red LEDs. Correct me if I'm wrong, but I'm going to use MOSFETs to switch this slightly larger amount of current. I want to solder the least amount of MOSFETs possible, so I want to use as many of the PWM outputs on my microcontroller instead.
Thanks!