4-Channel I2C PCA9536 Optical Isolated Digital Input with I2C Interface

Products
1

I’m having trouble communicating with the board. I’m using address 0x41 with no reply.

I’ve also run a I2C detection tool to see if I have the wrong address, but nothing is seen on any address as shown here:

pi@raspberrypi:~ $ i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: – -- – -- – -- – -- – -- – -- –
10: – -- – -- – -- – -- – -- – -- – -- – --
20: – -- – -- – -- – -- – -- – -- – -- – --
30: – -- – -- – -- – -- – -- – -- – -- – --
40: – -- – -- – -- – -- – -- – -- – -- – --
50: – -- – -- – -- – -- – -- – -- – -- – --
60: – -- – -- – -- – -- – -- – -- – -- – --
70: – -- – -- – -- – --
pi@raspberrypi:~ $

2

Hi,
can you share a picture of the setup.

Thanks

3

I’m using Go lang programming with github.com/d2r2/go-i2c to connect. I’m already using this for the 2 channel 4-20ma I2C module so I know the setup is correct. The PCA9536 manual states on page 7, the address is fixed at 1000001.

This is my connecting statement:
i2c, err := i2c.NewI2C(0x41, 1)

I use this to successfully connect to the 2 channel 4-20mA board:
i2c, err := i2c.NewI2C(0x48, 1)

Plugging in the PCA9536 to the RPI4 and daisy chaining the ADS1115 as the second device in the string, only the ADS1115 shows up with the i2cdetect tool.

pi@raspberrypi:~ $ i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: – -- – -- – -- – -- – -- – -- –
10: – -- – -- – -- – -- – -- – -- – -- – --
20: – -- – -- – -- – -- – -- – -- – -- – --
30: – -- – -- – -- – -- – -- – -- – -- – --
40: – -- – -- – -- – -- 48 – -- – -- – -- –
50: – -- – -- – -- – -- – -- – -- – -- – --
60: – -- – -- – -- – -- – -- – -- – -- – --
70: – -- – -- – -- – --
pi@raspberrypi:~ $

I changed the jumper from External power to bus power and now it shows up:
pi@raspberrypi:~ $ i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: – -- – -- – -- – -- – -- – -- –
10: – -- – -- – -- – -- – -- – -- – -- – --
20: – -- – -- – -- – -- – -- – -- – -- – --
30: – -- – -- – -- – -- – -- – -- – -- – --
40: – 41 – -- – -- – -- 48 – -- – -- – -- –
50: – -- – -- – -- – -- – -- – -- – -- – --
60: – -- – -- – -- – -- – -- – -- – -- – --
70: – -- – -- – -- – --
pi@raspberrypi:~ $

So now I’m confused about what the external and bus power is referring to. My digital input is going to be a 30V DC, powered from the external device.