PiMoroni pHAT Stack and ClusterHAT

[Jack W Hallmark]

1) Can the I2C address be changed?

2) What are the GPIO pins used on the Cluster HAT; and can the pin assignments be changed?

I am seriously considering trying to build a cluster of ClusterHATs using the pHAT Stack from SparkFun.

Thanx!

Jack

[Chris Burton]

Hi, 

1) Can the I2C address be changed?

Starting with Cluster HAT v2.4 I added solder bridges on the back of the PCB so you can select the I2C address for both the HAT EEPROM and I/O Expander.

 

2) What are the GPIO pins used on the Cluster HAT; and can the pin assignments be changed?

The pins can't be changed easily, both use 5v, 3.3v, GND and the ID_SC/ID_SC for the HAT EEPROM.

v1.x use GPIO21 (alert LED) and GPIO22-GPIO25 (p1-p4).

v2.x use I2C on GPIO2/3.

 

I am seriously considering trying to build a cluster of ClusterHATs using the pHAT Stack from SparkFun.

Using the Pimoroni pHAT stack you'll probably need to stagger the HAT height to plug the USB cable in if you're using v2.

You also might want to take a look at my Butterfly boards which give easy access for the USB cables.

Please also remember if you use a Pi earlier than the Pi4 you can only have 6/7 USB devices connected to it.

Chris.

[Jack W Hallmark]

Do you foresee any difficulties with conflicts, when setting different I2C addresses, using either the pHAT Stack or the Butterfly boards?

Thanx!

Jack

[Chris Burton]

Hi, 

Do you foresee any difficulties with conflicts, when setting different I2C addresses, using either the pHAT Stack or the Butterfly boards?

The Cluster HAT has both HAT EEPROM and I/O Expander on different i2C busses so you'll need to alter both of those (using the solder jumpers) if you're connecting more than one to to a single Pi via either butterfly or pHAT stack.

I've added a bit to the XA0/XA1 section there to explain how you can copy the clusterctrl tool/config and modify it to access a HAT on a different I2C address until the newer version is ready.

Chris.