SBAA288A July   2018  – January 2019 ADS7142

 

  1.   TM4C1294 interface to ADS7142 software library
    1.     Trademarks
    2. 1 Introduction
    3. 2 Hardware
    4. 3 Software
      1. 3.1 Header Files
      2. 3.2 ADS7142 Device Functional Modes Overview
      3. 3.3 Software Functions
    5. 4 Using the Software
      1. 4.1 Prerequisites
      2. 4.2 Getting Started
      3. 4.3 Using the Library
    6. 5 Main Routines and Test Data
      1. 5.1 Manual Mode
      2. 5.2 Autonomous Mode With Pre-Alert
      3. 5.3 Autonomous Mode With Post-Alert
      4. 5.4 Autonomous Mode With Start Burst Data
      5. 5.5 Autonomous Mode With Stop Burst Data
      6. 5.6 High Precision Mode
    7. 6 References
  2.   Revision History

5 Main Routines and Test Data

When developing this firmware framework, Texas Instruments used a National Instruments VirtualBench to set two DC inputs to the ADS7142 for testing of dual-channel sampling capability. One input was set slightly above the middle of the ADS7142 full-scale range, and the other set one volt above this level. The reference on the ADS7142BoosterPack™ is set to 3.3 V so voltage inputs to the ADS7142 channels are limited to a maximum of 3.3 V. The output code equation in decimal for a SAR ADC is:

Equation 1. O u t p u t   C o d e   ( d e c i m a l )   =   V i n p u t V R e f × 2 R e s o l u t i o n

For convenient conversion of decimal output codes to hexadecimal output codes TI recommends using the Analog Engineer's Calculator. The calculator contains an ADC Code to Voltage converter under the Data Converters calculator. The logic analyzer used to decode the I2C data provides outputs in hexadecimal form.