Main component :
PCA9685 - LED Display Drivers
• 1 MHz Fast-mode Plus compatible I2C-bus interface with 30 mA high drive capability on SDA output for driving high capacitive buses
• 4096-step (12-bit) linear programmable brightness per LED output varying from fully off (default) to maximum brightness
• LED output frequency (all LEDs) typically varies from 24 Hz to 1526 Hz (Default of 1Eh in PRE_SCALE register results in a 200 Hz refresh rate with oscillator clock of 25 MHz.)
• Sixteen totem pole outputs (sink 25 mA and source 10 mA at 5 V) with software programmable open-drain LED outputs selection (default at totem pole). No input function.
• Output state change programmable on the Acknowledge or the STOP Command to update outputs byte-by-byte or all at the same time (default to ‘Change on STOP’).
• Active LOW Output Enable (OE) input pin. LEDn outputs programmable to logic 1, logic 0 (default at power-up) or ‘high-impedance’ when OE is HIGH.
• 6 hardware address pins allow 62 PCA9685 devices to be connected to the same I2C-bus
• Toggling OE allows for hardware LED blinking
• 4 software programmable I2C-bus addresses (one LED All Call address and three LED Sub Call addresses) allow groups of devices to be addressed at the same time in any combination (for example, one register used for ‘All Call’ so that all the PCA9685s on the I2C-bus can be addressed at the same time and the second register used for three different addresses so that 1⁄3 of all devices on the bus can be addressed at the same time in a group). Software enable and disable for these I2C-bus address.
• Software Reset feature (SWRST General Call) allows the device to be reset through the I2C-bus PCA9685 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2015. All rights reserved. Product data sheet Rev. 4 — 16 April 2015 3 of 52 NXP Semiconductors PCA9685 16-channel, 12-bit PWM Fm+ I2C-bus LED controller
• Internal power-on reset
• Noise filter on SDA/SCL inputs
• Edge rate control on outputs
• No output glitches on power-up
• Supports hot insertion
• Low standby current
• Operating power supply voltage range of 2.3 V to 5.5 V
• 40 to +85 degree operation
• ESD protection exceeds 2000 V HBM per JESD22-A114, 200 V MM per JESD22-A115 and 1000 V CDM per JESD22-C101
• Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA
• Packages offered: TSSOP28, HVQFN28
PwmTest.py * functions *
def getInfo(Number) : Getting hardware information of device board
Number : connector number of baseboard
def initPwm() : initialize PWM signal for RC servo motor.
def setServoPulse(n,pulse) : Read Photo sensor voltage.
n : channel number
pulse : 12 bit duty.