Dear,
using the Adafruit 16-Channel 12-bit PWM/Servo Driver - I2C interface - PCA9685 and scanning the I2C Bus with only connected this device I get two different addresses:
1. 0x40 (I found in your tutorials)
2. 0x70
Is it right?
Regards
Tim
PCA9685 and two different I2C addresses?
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- adafruit_support_bill
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Re: PCA9685 and two different I2C addresses?
Hmmm. Does the 0x70 go away when you disconnect the PWM driver?
0x70 is the default address for most of our LED matrix & 7-segment displays.
0x70 is the default address for most of our LED matrix & 7-segment displays.
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- Posts: 13
- Joined: Mon Feb 10, 2014 5:23 pm
Re: PCA9685 and two different I2C addresses?
Yes, there is no 0x70 address after taking away the PCA9685. Please take a look to the uploaded pictures. You will see the wiring without any servos connected. For testing I used both sides of the I2C Bus with the same result of displaying two addresses. Connecting a 5V external power supply and a servo motor at channel 0 using your example sketch "servo" works fine, because address 0x40 should be talkable.
I ordered some other components, for example the BMP180 pressure sensor or your Ultimate GPS Breakout v3 - all these components have their correct address and working at my arduino UNO R3.
I ordered some other components, for example the BMP180 pressure sensor or your Ultimate GPS Breakout v3 - all these components have their correct address and working at my arduino UNO R3.
- Attachments
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- Running servo sketch successfully turns the servo
- i2c_pca9685_servo_sketch_running.jpg (31.38 KiB) Viewed 4678 times
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- I2C Scanner running with PCA9685 connected
- i2c_pca9685_scanner_sketch_running.jpg (28.48 KiB) Viewed 4678 times
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- Wiring the board
- i2c_pca9685_wiring.jpg (159.46 KiB) Viewed 4678 times
- adafruit_support_bill
- Posts: 88086
- Joined: Sat Feb 07, 2009 10:11 am
Re: PCA9685 and two different I2C addresses?
This is normal for this chip. In addition to the regular addressing which starts at 0x40, there is an "All Call" address at 0x70 for addressing all PCA9685 devices simultaneously. See section 7.1.2 of the datasheet: http://www.adafruit.com/datasheets/PCA9685.pdf
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- Posts: 13
- Joined: Mon Feb 10, 2014 5:23 pm
Re: PCA9685 and two different I2C addresses?
Thanks for the information. In this way it is an interesting feature, I did not found because I have always my first one
Regards Tim
Regards Tim
Please be positive and constructive with your questions and comments.