Problems Communicating with Adafruit PCA9685

Hello All,

I am planning on controlling an RC car motor and servo (Traxxas 2075) using the PCA9685 servo driver, and a traxxas ESC. (The driver is powered by a 4 x AA battery pack) I have connected my driver to the Xavier as follows (Bus 1):

GND Pin 6 -> Servo Driver (GND)
VCC Pin 2 -> Servo Driver (VCC – 5V)
SDA Pin 27 -> Servo Driver (SDA)
SCL Pin 28 -> Servo Driver (SCL)

But whenever I run the command

sudo i2cdetect -y -r 1

I get this result:
https://imgur.com/a/v69Glc6

And everytime I try to run the example file from JetsonHacks (https://github.com/jetsonhacks/JHPWMDriver) I receive the error:

PCA9685 Write Byte error: 121PCA9685

Any ideas on why it is not connecting?

Thanks, Luke

EDIT
My mistake, I had the address set to 0x40 in this line:

PCA9685 *pca9685 = new PCA9685(0x40);

When the servo was actually connected at address 0x70.
Problem solved.

Good to know you resolved the problem, and looking forward to see your project video sharing in forum.
Thanks.

Hi, I am having the same problem as you.
Can you explain what you did to solve it ?
sudo i2cdetect -y -r 1
[sudo] password for prophet:
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: – -- – -- – UU – -- – -- – -- –
10: – -- – -- – -- – -- – -- – -- – -- – --
20: – -- – -- – -- – -- – -- – -- – -- – --
30: – -- – -- – -- – -- – -- – -- – -- – --
40: UU UU – -- – -- – -- – -- – -- – -- – --
50: – -- – -- – -- – -- – -- – -- – -- – --
60: – -- – -- – -- – -- – -- – -- – -- – --
70: – -- – -- 74 – -- –
prophet@prophet-desktop:~$

or this
sudo i2cdetect -y -r 0
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: – -- – -- – -- – -- – -- – -- –
10: – -- – -- – -- – -- – -- – -- – -- – --
20: – -- – -- – -- – -- – -- – -- – -- – --
30: – -- – -- – -- – -- – -- – -- – -- – --
40: – -- – -- – -- – -- – -- – -- – -- – --
50: 50 – -- – -- – 56 – -- – -- – -- – -- –
60: – -- – -- – -- – -- – -- – -- – -- – --
70: – -- – -- – -- – --

hello cespedesk

is there still an issue to communicate with Adafruit PCA9685?
may I also have your confirmation that which platform you’re working with?

since you’d also report an issue on Nano platform here: Topic 75767,
however, you’d confirmed it works in Topic 146769.
thanks

I don’t know how but the servos are working, looks like my numbers are just diferent but it connected.Thanks.