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OPT3101EVM: I want to retrieve measurement data.

Ryu Yamashita
Genius 3685 points
Part Number: OPT3101EVM
Other Parts Discussed in Thread: MSP430F5503, OPT3101

Tool/software:

Hi team,

I want to acquire measurement data without using GUI.
I cannot use a PC, so we want to acquire and record data using some kind of microcontroller.
However, we want to do this in the EVM calibration state, so we want to do it with EVM without using the GUI.
Is there any way to do this?

Best Regards,
Ryu.

  • +1
    TI__Expert 4190 points

    Hello Ryu, 

    You will need to thoroughly review the 3101 register read/write values in section 7 of data sheet  as well as the layout and operation of the EVM itself. You will need to write your own firmware for microcontroller you utilize to interact with the firmware on the EVM board, this will likely be the easiest way to achieve your goals. 

    3.1 MSP430 Microcontroller The MSP430F5503 has a USB interface, allowing connection to a PC, and acts as a communication bridge between the OPT3101 and the PC. The MSP430 microcontroller is loaded with C++ firmware for interfacing with the OPT3101 over I 2C, in addition to the other components on the PCB. The MSP430 also has a calibration configuration for the board stored in onboard flash storage. The MSP430 registers 2 USB COM ports with the PC it is plugged in to. The OPT3101 Control Port is used for sending control commands to the MSP430. This includes reading and writing registers on the OPT3101 and interfacing with the MSP430 flash storage. The OPT3101 Data Port is used only for streaming data from the EVM to the PC. This allows for maximum data rates when receiving real-time data from the OPT3101 during high-speed capture.

    3.2 I 2C Buses and Temperature Sensor The OPT3101 has two I 2C buses. On the main I 2C bus, labeled I2C_S, the OPT3101 is a slave device. This bus is used to control the OPT3101 and read data by reading and writing registers on the device. The OPT3101 also has a secondary I 2C bus, I2C_M, for which it is the master. This bus allows an external temperature sensor and an EEPROM to be controlled by the OPT3101. The OPT3101 contains an internal temperature sensor, which is used for temperature calibration. This sensor has 8-bit integer resolution. Adding an external temperature sensor, such as that used on the EVM, allows up to 12 bits of resolution to be obtained with one sign bit, 7 integer bits, and 4 fractional bits. This allows for more accurate temperature correction. An external EEPROM allows for an OPT3101 register configuration to be stored and loaded on power-up. This means that the device does not need an I 2C master to configure it on power-up. On the EVM, only a temperature sensor is used on this bus.

    Thank you, 

    Joseph Scherphorn

  • 0 in reply to Joseph Scherphorn
    Genius 3685 points

    Hi Joseph,

    Thanks for the reply.
    So it is not possible to disconnect the MSP430 and use only the I2C pins to control it with another CPU?
    I suppose it could be done by copying all the I2C communication, but I was hoping to achieve this using an SDK or similar.
    I will eventually design everything including calibration, but first I wanted to test the measurements using EVM and other CPUs.

    Best Regards,
    Ryu.

  • 0 in reply to Ryu Yamashita
    TI__Expert 4190 points

    Hello Ryu, 

    The method you describe is possible, but it may be helpful to realize that all the python scripts are open in Latte and can be viewed by you when you download the GUI.

    Thank you, 

    Joseph Scherphorn