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    basgoossen

    @basgoossen

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    Posts made by basgoossen

    • RE: Heart Unit with Core 2 - any suggestions?

      PPG is pretty finicky and the signal more often than not requires cleanup by software algorithms. Double readings are not uncommon and appear even in medical grade sensors. Most sensors used nowadays have multiple emittors or a single emittor with multiple sensors. The "evaluation sensor" with one led and one sensor used for this device will indeed require very precise and stable placement. Even so i'd recommend trying to get the raw signal out of the sensor if possible at 24-40hz (24 and 40hz are commonly used for PPG processing algorithms and usually a good place to start from). working with and visualising the raw signals will give you a much better insight of what you're measuring.

      Current supplyed by the Core2 is not gona be a limiting factor in this. Noise of the voltage convertor could cause issues, but this can only be checked if the raw signal is analysed. Often sensors make use of motion sensors to discard readings during detected motion.

      posted in Units
      B
      basgoossen
    • RE: <SOLVED> M5Stack basic vs gray and SD card

      Glad to hear it worked for you too!

      posted in Arduino
      B
      basgoossen
    • RE: <SOLVED> M5Stack basic vs gray and SD card

      I also had some issues with the M5Stack basic and SD cards. I was unable to read 9 out of 10 cards. In the end i ended up slowing down the SD card clock from 40Mhz to 10Mhz, this solved all the read issues for me. You can achieve this by editing the M5Stack.cpp file, in the function M5Stack begin SD is enabled using the following function:

      // TF Card
      if (SDEnable == true) {
          SD.begin(TFCARD_CS_PIN, SPI, 40000000);
      }
      

      I changed this to:

      // TF Card
      if (SDEnable == true) {
          SD.begin(TFCARD_CS_PIN, SPI, 10000000);
      }
      

      Since than i have had no more troubles reading from and writing to the SD card.

      posted in Arduino
      B
      basgoossen
    • PBHub v1.1 (STM32F030F4p6) FW Source

      Hi all,
      I'm willing to add a counter functionality to the PBHub v1.1. It seems possible from the spec sheet of the STM32F030F4p6 used in this device. Also the programming pins are broken out, so reprogramming the chip is not too hard. It whould be very preferrable to add the functionality on the existing FW instead of creating the FW from scratch. In the github of m5stack i was only able to find the FW of the EXT.IO using the same chip, however the PBHub v1.1 is not listed. Any idea's on this one? Also when playing with custom FW, it whould be nice to have the option to reflash the factory firmware.
      Best regards, and thanks,
      Bas

      posted in Units
      B
      basgoossen