First Time Using SPresence, Simple Questions about Technicial Specs



  • Hi,

    This is my first time using the SPresence Main Board (CXD5602PWBMAIN1) and SPresence Camera Board and I am using it for a project. In this project the SPresence devices will be part of a mobile battery powered system and I have the following questions I would like to have answered before I start working with the device:

    1. If I were to power the SPresence Main Board with an external power supply, what is the minimum and maximum voltage and current I should feed into the device assuming no additional devices are attached? Do I use the EXT_VDD pin to power the board with an external supply (I assume yes)? I see that it can take a 5V power supply from the USB can I also use a external 5V Power Supply to power the device?

    2. Product 1: How much current do the GPIO pins individually output when used as an output? What is the voltage of a logic 1 output on an individual GPIO pin? How much current should I be feeding into the GPIO pin if I use the individual pin as an input? What voltage should I be feeding into the GPIO pin if I use the individual pin as an input?

    3. How much current does the SPresence 5MP Camera Board draw/use?


  • DeveloperWorld

    @Vraj-Patel said in First Time Using SPresence, Simple Questions about Technicial Specs:

    ?

    Product 1: How much current do the GPIO pins individually output when used as an output? What is the voltage of a logic 1 output on an individual GPIO pin? How much current should I be feeding into the GPIO pin if I use the individual pin as an input? What voltage should I be feeding into the GPIO pin if I use the individual pin as an input?

    Hi @Vraj-Patel
    Good to hear that you have chosen Spresense for your project.
    For question #1:
    On this page you will find information on how to power the main board:
    https://developer.sony.com/develop/spresense/developer-tools/hardware-documentation#_powering_the_main_board_with_external_power

    On GitHub you will also find the schematic. Please note that EXT_VDD is called ACP_PWR.
    https://github.com/sonydevworld/spresense-hw-design-files/tree/master/CXD5602PWBMAIN1/schematics

    To summarize this, the document above states that it is recommended to use the battery connector to power the Spresense board.
    But looking at the schematics you can see that the BATT_VDD is connected to ACP_PWR which is EXT_VDD through a reverse current block ic.

    Question #2:
    The GPIO on the main board (please be aware that this applies only to the main board, for the extension board the figures are different!) the GPIO voltage is 1.8V so a logical 1 when the pin is configured as output will be 1.8V.
    The VIH voltage when the pin in is configured as input is minimum 0.65 * VDD18 (~1.17V).
    Before you feed any voltage on any GPIO pin please make sure that you have configured it as an input otherwise the CXD5602 chip will likely be destroyed.
    You'll find all the details in the technical manual for the chip CXD5602: https://www.sony-semicon.co.jp/products_en/spresense/PDF/CXD5602GG_technical_manual.pdf

    Question #3:
    Don't know, have no figures for now.

    Hope that this will help you on the way.



  • @TE-KarlKomierowski Okay but I still have one concern, the specifications say that the SPresence camera operates at 3.7V and the board takes only a 3.7 to 4.4V battery via the CN1 connector. Is this a problem if I order a 3.7V battery? What voltage should the battery be? Note, I am not using the extension board and I noticed most of the projects have used the extension board with the camera, I am hoping it is not necessary.


  • DeveloperWorld

    @Vraj-Patel said in First Time Using SPresence, Simple Questions about Technicial Specs:

    this a problem if I order a 3.7V battery? What voltage should the battery be? Note, I am not using the extension board and I noticed most of the projects have used the extension board with the camera, I am hoping it is not necessary.

    Hi @Vraj-Patel
    A single cell LiPo battery will work just fine. They can be specified to be 3,7-4,2 V but they are basically the same voltage wise, the voltage vary with the remaining charge in the battery.
    Here is some information about that:
    https://learn.adafruit.com/li-ion-and-lipoly-batteries/voltages

    You can use the camera with only the main board. The chipset/mainboard have regulators and "everything" needed onboard to have the camera working if you power the board from a battery.



  • @TE-KarlKomierowski Thank you for all your help! Really appreciate it.