¶ I2C Address Clash
The I2C components on the CMDmux board can clash with components on the Active Board itself. The fixes are outlined below.
¶ AD7993 (ADC)
The ADC clashes with the (same) ADC's on the Active Board and the MCP23017 IO expander on the Carrier Cards.
Use the AD7993-1 model that avoids clashes with AD7993-0 (Active Board) and the IO expander. The resulting address is 0x24.
¶ MCP23008 (IO Expander For Mux Selection)
The original address (0x21) clashes with the OFin driver on the Carrier Card and the LV ADC on the Active Board. The fix is to change the address to 0x27 by modifying the connections on the PCB.
- Cut the
A1/A2connection to ground. This is below the MCP23008 chip and thus has to be done before the chip is loaded.
- Once he MCP23008 is loaded, short the
A0/A1/A2pins together. In principle, onlyA1has to be shorted toA0. TheA1andA2are already connected between the pads.
