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iSpindel Support

vitotai edited this page Apr 18, 2018 · 3 revisions

Connection setup for iSpindel

BrewPiLess supports iSpindel by accepting data from iSpindel and acting an AP for iSpindel to connect to, BrewPiLess and iSpindel can connect to the same router. To support softAP, set the correct settings in System configuration. Please note that the password(passphrase) should be at least 8 characters. The same password(pass phrase) is used for setting and for connection certification. Default value is brewpiless.

Gravity Sensor

Setting Description
iSpindel To enable iSpindel support.
Calculated by BPL Do the conversion from tilt angle to gravity by BrewPiLess. If this option is OFF, all the following options are not used.
SG Calibration Deprecated.
Temp. Correction Apply temperature correction to the calculated gravity reading. Celsius only. Usually it is 20°C(68°F) or 15°C(59°F).
Coefficients The coefficients of the formula to calculate gravity. Note: this set of coefficients is for calcuation of specific gravity, not plato. Use 0 for x^3 term if quadratic polynomial is used.
LowPass Filter Coefficient 0~1. See following description
Gravity Stability Threshold Integer value. 1 point = 0.001.

When running "Brew N Cal", the coefficients of the formula will be updated by the web page frontend. BPL will calculate gravity based on the updated formula automatically. Please note that, due to the limited precision of float on ESP8266, the values might be different from what you can see on the browser.

After v2.6, Offset of gravity reading is not available. You can add the offset to the last parameter of the formula,the constant term, and have the same result.

iSpindel Settting

  • the iSpindel Name must start with iSpindel, like iSpindel000
  • Select Generic HTTP
  • Server address set to 192.168.4.1 if iSpindel connect to the AP created by BrewPiless. or use the ip of BrewPiless if iSpindel connects the AP that BrewPiLess connects to.
  • set url to /gravity

For other iSpindel setting, like network settting, please refer to iSpindel project.

About low Pass Filter

Low Pass Filter The coefficient defines the 'a' in this LPF: y = y[i-1] + a ( x - y[i-1] ) It is usually set to 1/f. So, 1/60 for one minute reporting period, and 1/6 for 10 minute reporteing period.

Note: enabling iSpindel setting only enables the initial display of iSpindel status. The gravity report will be processed even when the option is OFF.

calibrationSG.htm in /extra folder is an utility HTML file which can be used to derive the coefficients instead of using the excel from iSpindel.

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