After developing several products focused on data acquisition, like the MRBW-RTS and a few currently in development like the MRB-DCCM (DCC Meter) and MRBW-DAQ (Data Acquisition node), we realized some of the ICs used in those designs would be useful on their own. To enable rapid development with these ICs, a series of ArduinoTM shields was created allowing you to easily implement a wide variety of data acquisition applications.
The ARD-LTC2499 puts together a high accuracy 24-bit ADC with a precision reference providing 8 differential input channels, 16 single-ended input channels, or any combination in between. The LTC2499 ADC is capable of directly converting a variety of inputs, including bridge transducers and even thermocouples and includes an internal temperature sensor that can be used for software-based cold-junction compensation. The input range is limited to 2.048V (50% of the reference voltage) by default, but this can be accommodated in most cases. The voltage reference is an LT6654 with 4.096V output voltage.
As with all our data acquisition Arduino shields, an EEPROM is also available for storing configuration coefficients or other data that travels with the shield (as opposed to inside the microcontroller on the Arduino board). The EEPROM also contains a 6-byte EUI-48TM-compatible globally unique ID to enable identification of specific boards or networked nodes.
A hardware reference can be found here describing the various jumpers and configuration options available on the board. A complete Arduino software library is also available. All communication with the board is via I2C.
The ARD-LTC1863 contains a 12-bit 200ksps ADC (LTC1863) with 8 single-ended inputs or 4 differential inputs. While the accuracy and resolution is not as good as the ARD-LTC2499, its speed is orders of magnitude better, making it suitable for many applications. The input range is 4.096V and an EEPROM for storing calibration data and providing a 6-byte EUI-48TM-compatible globally unique ID is also available.
Due to the data conversion speed, SPI is used to achieve the full data rate. Therefore, the ICSP header must be available to this shield. The EEPROM communicates via I2C.
The ARD-LTC2990 provides access to two LTC2990 Voltage, Current, and Temperature monitors. These parts let you measure single-ended voltage, differential voltage, or temperature using inexpensive and commonly available 2N3904 type transistors. The ARD-LTC2990 can measure up to 8 single-ended voltages, 4 differential voltages, 4 temperatures, or various combinations.
All communication is via I2C, including the onboard EEPROM for calibration coefficients and the 6-byte EUI-48TM-compatible globally unique ID. A hardware reference is available, as is a complete Arduino software library.