Connect TCA9548A to SSC 32-U

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dwulkan
 
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Connect TCA9548A to SSC 32-U

Post by dwulkan »

I have a robot using a Raspberry pi 3 and a SSC 32-U motor controller. Now, I am trying to hook up my TCA9548A i2c multiplexor. The connections look like this:

SSC 32-U (Analog/Digital I/O pins right to left)
B/SDA A/SCL
6 3
5 2 5v
4 1 G

TCA9548A
VIN = 2
GND = 1
SDA = 6
SCL = 3
RST Not Used

Idetect doesn't see the mux device. Do I need to tie the SSC 32-U pins 1 and 4 (GND) together?

Code: Select all

$ sudo i2cdetect 1
WARNING! This program can confuse your I2C bus, cause data loss and worse!
I will probe file /dev/i2c-1.
I will probe address range 0x03-0x77.
Continue? [Y/n] Y
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --    
Thanks

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adafruit_support_mike
 
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Re: Connect TCA9548A to SSC 32-U

Post by adafruit_support_mike »

You do need a common GND for all the devices in the system. That's the reference point from which all other voltages are measured.

Post a photo showing your hardware and connections and we'll take a look. 800x600 images usually work best.

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dwulkan
 
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Re: Connect TCA9548A to SSC 32-U

Post by dwulkan »

Ok, I have image but, I don't think you can determine more than what I have already told. I made dupont connectors. A 5 pin connector for the TCA9548A (I wasn't sure I needed to connect the RST - or even how to make it work?) So. RST has no connection but, wire and connector slot is available. The pin is this:

Code: Select all

TCA9548A
VIN = 1
GND = 2
SDA = 3 
SCL = 4 
RST = 5 Not Used/Not connected to a wire
The SSC 32-U is shown in the image. I made one three-slot female connector for port A on the SSC 32-U. A is from bottom to top in the image, GND, 5V & SCL. I made another three-slot female connector that only has one wire. This is SDA on the SSC 32-U port B. I had originally asked if I need to tie or short Port B Gnd to Port A Gnd? The SSC 32-U is configured this way:

Code: Select all

Ports (as you see them)
A  SCL  to TCA9548A  SCL
A  5v     to TCA9548A  VIN
A  GND to TCA9548A GND

B  SDA  to  TCA9548A  SDA
B 5v      Not connected to anything
B  GND Not connected to anything
P1010032.jpg
P1010032.jpg (181.15 KiB) Viewed 274 times

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adafruit_support_mike
 
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Re: Connect TCA9548A to SSC 32-U

Post by adafruit_support_mike »

If the TCA9548 is connected to the SSC 32-U's I2C pins, running `i2cdetect` on the RasPi won't do anything. That looks for signals on the SDA/SCL pins of the RasPi's GPIO header.

I don't know anything about the SSC 32-U's I2C interface, but that's where you need to look for the TCA9548.

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