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bwhitman

Member Since: March 3, 2008

Country: United States

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co-founder & CTO of The Echo Nest

personal website

  • Big errata – the datasheet Sparkfun has is out of date. This is the new one:

    http://www.atlas-scientific.com/files/datasheets/_circuit/pH_EZO_datasheet.pdf

    most importantly, the default baud rate is no longer 38400, it is 9600. Hopefully this will save the rest of you the hours I just spent trying to get this to not return garbage characters :)

  • I could not get the Phant to work on a Sparkfun Photon Redboard, and discovered I had to make a change to the HTTP POSTing code. I discovered the POSTing logic suggested by Sparkfun in their official Particle Phant wrapper is different from the example code in Sparkfun_Photon_Weather_Phant. Precisely, you want the code in postToPhant to look like

    if (client.connect(server, 80))
    {
        Serial.println("Posting!");
        client.print(phant.post());
        int timeout = 1000;
        while (client.available() || (timeout-- > 0))  {
            char c = client.read();
            if (i < 512)
                response[i++] = c;
            delay(1);
        }
    

    Instead of the delay(1000) stuff.

  • Love this Thing. We made a super simple IoT sensor for baking bread with it, parts list and code included: https://github.com/bwhitman/bread-detector

  • Does anyone know the minimum sensing distance of this?

  • I did a dumb calibration / “best fit” power curve in Excel after some measurements of the voltage reading in an Arduino to inches, here’s my function:

    int sensorValue = analogRead(A0);
    float inches = pow(sensorValue,-0.867) * 539.98;
    

    This is using 5V USB powering the board and the Vcc going to a 5V pin on the arduino.

    Hope this helps anyone using this

  • hi – I had the usual problems getting this thing to talk to a “real computer” so i wrote up my steps and posted all the code I used. More or less, I run a tiny stub piece of code on an Atmel that listens to its UART over 9600bps and sends commands to a connected backpack over SPI. This lets me then control the matrix from almost anything at a pretty good FPS without any complications. Here it all is, enjoy:

    https://github.com/bwhitman/rgb-backpack-controller