Some questions about OpenLog Artemis

Development Boards Artemis
1

Hello, I need to know the following before placing an order urgently. Could you please let me know the answers?

  1. So the OpenLog Artemis can log data at 1msec resolution but it has a slow SD card slot. How does it save all the data without missing any? Through a large buffer?

  2. Do you have another product that can log data at msec, ideally 1msec, resolution but can also be controlled by ESP-S3 Think Plus? If not, I would consider saving at time interval of about 10msec. Ideally, I want this information:

    1msec, sensor data, several other data from ESP32-S3

    2 msec, sensor data, several other data from ESP32-S3

    3 msec, sensor data, several other data from ESP32-S3, etc.

  3. It seems that the OLA can only receive data from sensor(s) connected to the ESP32-S3 via UART. The ESP32-S3 cannot use the OLA’s higher resolution clock. Am I right?

  4. I know we set the time of the OLA’s RTC by manually typing the time via a serial terminal. Is it possible to sync the clock of the OLA from a PC so that both the OLA and ESP32-S3 have the same time for data synchronization between the two during post-processing stage?

Thank you

Sparkfun ESP32-S3 Think Plus compatibility with Adafruit Ultimate GPS FeatherWing - PA1616D
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Hi @sparkfun_user ,

I have been reluctant to answer any of your questions, because I suspect I will get many more questions back in return… :wink: You have posted a lot of questions, some of which could be answered by simply reading the product descriptions and hook-up guides. We all have limited time. Please only ask questions when you really can’t find the answer to them yourself.

You need to think through your application a little more and think about what will limit the logging speed.

Will the SD writing limit the speed? SDIO is faster than SPI. The Datalogger IoT (SDIO) can log data much faster than OpenLog Artemis (SPI).

If you are using UART to transfer data from the Thing Plus, how much data are you transferring and at what baud rate? Will that limit the speed?

If you are reading sensors over I2C, how much data are you trying to read and how often? Will the 100kHz / 400kHz I2C bus speed be the limiting factor?

Can you read your sensor(s) over SPI? It is much faster than I2C. The IMU and magnetometer on the Datalogger IoT 9-DOF are connected over SPI.

If you only want to log IMU data at 1kHz, that is achievable. There is a stand-alone Datalogger 9-DOF example which shows how to achieve that. You may find the other test examples useful. You may be able to reuse some of them on the S3.

For time synchronisation: synchronising to the Pulse Per Second output from a GNSS receiver is likely to give the best results. The OLA can synchronise its RTC to a u-blox GNSS, but it does not use the PPS pin, only the arrival of the I2C Position-Velocity-Time message. The Datalogger IoT can synchronise the ESP32 RTC to network time using WiFi and Network Time Protocol. There are many possible solutions. You need to pick the one which best meets your needs.

Best wishes,
Paul

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