2 servo shields

[skypickle]

What's the difference between these two:

https://www.adafruit.com/product/815
https://www.adafruit.com/product/1411

Both are 16 channel 12 bit
Both have a i2c-controlled PWM driver with a built in clock
Both are stackable
Both have an Adjustable frequency PWM up to about 1.6 KHz

Product 1411 is 'arduino ready' whatever that means?
Product 1411 is on a bigger pcb with more empty holes whatever they're for?
Product 1411 uses I2C 7-bit addresses between 0x60-0x80, selectable with jumpers.

Product 815 uses I2C 7-bit address between 0x40-0x7F, selectable with jumpers

But why are there two almost identical products?

[adafruit_support_bill]

I'll take the last question first:

But why are there two almost identical products?

Actually, there are five:
https://www.adafruit.com/product/815
https://www.adafruit.com/product/1411
https://www.adafruit.com/product/2327
https://www.adafruit.com/product/2928
https://www.adafruit.com/product/3416

These are all based on the same PCA9685 PWM generator chip. This is a versatile chip for driving LEDs, Servos and most anything else that needs a Pulse-Width-Modulated signal.
The #815 was the original breakout board version.
The #1411 is designed around the Arduino shield format so that it will plug directly into an Arduino.
The #2327 and #3416 are designed around Raspberry Pi standards
And the #2928 is designed for plug-compatibility with our Feather line of processors. https://blog.adafruit.com/2018/04/24/th ... -adafruit/