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
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¶
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:
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.