Hardware Overview

The MCC DAQ HATs are Raspberry Pi add-on boards (Hardware Attached on Top). They adhere to the Raspberry Pi HAT specification, but also extend it to allow stacking up to 8 MCC boards on a single Raspberry Pi.

C and Python libraries, documentation, and examples are provided to allow you to develop your own applications.

MCC 118

The MCC 118 is an 8-channel analog voltage input board with the following features:

  • 12-bit, 100 kS/s A/D converter
  • ±10 V single-ended analog inputs
  • Factory calibration with ±20.8 mV input accuracy
  • Bidirectional scan clock
  • Onboard sample buffers
  • Digital trigger input
MCC 118 circuit board

Board components

Screw terminals

  • CH 0 In to CH 7 In (CHx): Single-ended analog input terminals.
  • Clock (CLK): Bidirectional terminal for scan clock input / output. Set the direction with software. Set for input to clock the scans with an external clock signal, or output to use the internal scan clock.
  • Trigger (TRIG): External digital trigger input terminal. The trigger mode is software configurable for edge or level sensitive, rising or falling edge, high or low level.
  • AGND (GND): Common ground for the analog input terminals.
  • DGND (GND): Common ground for the clock and trigger terminals.

Address jumpers

  • A0 to A2: Used to identify each HAT when multiple boards are connected. The first HAT connected to the Raspberry Pi must be at address 0 (no jumper). Install jumpers on each additional connected board to set the desired address. Refer to the Installing multiple boards topic for more information about the recommended addressing method.

Status LED

The LED turns on when the board is connected to a Raspberry Pi with external power applied and flashes when communicating with the board. The LED may be blinked by the user.

Header connector

The board header is used to connect with the Raspberry Pi. Refer to Installing the DAQ HAT board for more information about the header connector.

Functional block diagram

MCC 118 block diagram

Functional details

Scan clock

The clock input / output (terminal CLK) is used to output the internal scan clock or apply an external scan clock to the device. The clock input signal may be a 3.3V or 5V TTL or CMOS logic signal, and the output will be 3.3V LVCMOS. A scan occurs for each rising edge of the clock, acquiring one sample from each of the selected channels in the scan. For example, when scanning channels 0, 1, and 2 the conversion activity will be:

MCC 118 clock mode

Trigger

The trigger input (terminal TRIG) is used to hold off the beginning of an analog input scan until the desired condition is met at the trigger input. The trigger input signal may be a 3.3V or 5V TTL or CMOS logic signal. The input condition may be rising edge, falling edge, high level, or low level.

Firmware updates

Use the firmware update tool to update the firmware on your MCC 118 board(s). The “0” in the example below is the board address. Repeat the command for each MCC 118 address in your board stack. This example demonstrates how to update the firmware on the MCC 118 that is installed at address 0:

mcc118_firmware_update 0 ~/daqhats/tools/MCC_118.hex

MCC 152

The MCC 152 is an analog output / digital I/O board with the following features:

  • 2 analog outputs
    • 12-bit D/A converter
    • 0 - 5 V outputs
    • 5 mA output drive, sourcing
    • Simultaneous update capability
  • 8 digital I/O
    • 5 V / 3.3 V supply voltage, jumper-selectable
    • Bit-configurable for input (power on default) or output
    • Outputs may be set to push-pull or open-drain (port-configurable)
    • Programmable pull-up/pull-down resistors (disconnected on outputs when set to open-drain)
    • 10 mA source/25 mA sink per output
    • Interrupt on input state change
MCC 152 circuit board

Board components

Screw terminals

  • AO0 to AO1 (AOx): Analog output terminals.
  • DIO0 to DIO7 (DIOx): Digital input/output terminals.
  • VIO (VIO): Digital I/O supply voltage (5 V or 3.3 V, selectable with jumper W3.)
  • AGND (AGND): Common ground for the analog output terminals.
  • DGND (DGND): Common ground for the digital I/O terminals.

Address jumpers

  • A0 to A2: Used to identify each DAQ HAT when multiple boards are connected. The first DAQ HAT connected to the Raspberry Pi must be at address 0 (no jumper). Install jumpers on each additional connected board to set the desired address. Refer to the Installing multiple boards topic for more information about the recommended addressing method.

DIO Power jumper (W3)

Status LED

The LED turns on when the board is connected to a Raspberry Pi with external power applied.

Header connector

The board header is used to connect with the Raspberry Pi. Refer to Installing the DAQ HAT board for more information about the header connector.

Functional block diagram

MCC 152 block diagram

Functional details

Mixing 3.3V and 5V digital inputs

The MCC 152 digital inputs are tolerant of 5V signals when the DIO is set to 3.3V operation with jumper W3. However, current can flow into the MCC 152 from the 5V signal, so the user must limit this current to avoid raising the voltage of the digital power supply rail (VIO) and possibly damaging components. MCC recommends using a series resistor of 700 ohms or larger.

Example:

MCC 152 resistor example