16 channel PWM Servo & 16 GPIO input/output with
16 Blue LED
The PCA9685 is an I2C-bus controlled 16-channel LED
controller optimized for LCD
Red/Green/Blue/Amber (RGBA) color backlighting
applications. Each LED output has its
own 12-bit resolution (4096 steps) fixed frequency
individual PWM controller that operates
at a programmable frequency from a typical of 40 Hz to
1000 Hz with a duty cycle that is
adjustable from 0 % to 100 % to allow the LED to be set
to a specific brightness value.
All outputs are set to the same PWM frequency.
PCA9685 also has a built-in oscillator for the PWM
control.
However, the frequency used for PWM control in the
PCA9685 is adjustable from
about 40 Hz to 1000 Hz as compared to the typical 97.6
kHz frequency of the
PCA9635. This allows the use of PCA9685 with external
power supply controllers. All
bits are set at the same frequency.
The PCA9685 has 4096 steps (12-bit PWM)
1. 2P Terminal Block 5V input for PWM V+ & GPIO output
pin 10 V+
2.
J3 DA0 ~ DA7 U14 Port A . J6 BA0
~ BA7 U14 Port B
3. R62,R63,R64 ( for U14 Address select A0,A1,A2)
4. U14 I2C 23017 -1 Port A,B
23017
Datasheet
5. U15 uln2803
6. U3 PCA9685 (PWM Port 0 ~ 15)
PCA9685 Data Sheet
7. R10,R11,R12,R13,R14,R15( for U3 Address select
A0,A1,A2,A3,A4,A5)
8.
Red power-good
V+ LED
9. 2
i2c device connect J20 GND,+5V,SDA.SCL ( with
level converter, safe for 5V device),
J21 GND
3V3,SDA,SCL

plug
in Raspberry Pi B2 with Servo motor
& Step Motor
in i2cdetect you
can found 2 device in system (21,41)
21 - 23017
41 - 9685
Support our Pi_Scratch software
Detail
(1) Servo Motor control

2 Servo in channel 0 & channel 7
Command "SE"+ "PWM (0-15)" + "a" +"angle" for Address 41
se7a10 --> channel 7 servo move 10 angle address 41
se7a-10 --> channel 7 servo move -10 angle address 41
se0a10 --> channel 0 servo move 10 angle address 41
se0a-10 --> channel 0 servo move -10 angle address 41
(2) PWM LED output demo

LED module (Blue, Green,Yellow,Red)
LED Scrolling Command PWMLED41S0E15D4True
PWMLED”Address” S[Start channel] E[End channel] D[Delay / Timing] [True/False]
Address 41, 42,43,44
Start channel & End channel 0 ~ 15 16 channel
D 1,2,3,4,5 (1 ~ 100) Delay Timing
LED Brightness control Command
PWMLED “Address” “B” “0 ~ 1000“
PWMLED41B1000
Stop command
"PWMLED41STOP"

Test Program
servo-40.py
servo-41.py
pwm