ISpindel

Projects
Participants	Einnor, Justa, Sikkepitje
Skills	soldering, brewing, PCB Design
Status	Active
Niche	FoodHacks
Purpose	Fun

iSpindel

iSpindel DIY continuous hydrometer, for measuring the realitive gravity / density of wort. Meant as an educational project for KWBG. We created footprint for the various parts on the PCB. These can be found in the /libs dir in the repo. Furthermore we replaced the reset switch with a reed switch so you can use a magnet to reset the iSpindel without opening the container.

Why Bat43???

It seems to me that the selection of the diode to be a schottky is a critical one here! According to the datasheet, the min. Input Low Voltage must be < 0.25×VIO while the Output Low Voltage is up to 0.1×VIO. Therefore, this leaves 500mV where the BAT43 will drop around 300mV or more. So a regular silicium diode will fail in this setup! Using a BAT43 or better is a requirement so to speak.

found here [iSpindel/issue/59]

Previous work:

• iSpindel - DIY electronic Hydrometer
• iSpindel by TheJeffrey

Look also here: github.com/techinc/ispindel_kicad

Subpage Dutch user documentation for setting up iSpindel with dataservices

Handy Formulas

Following formulas can be used to convert Gravity values from degrees P to SG and vice versa. Plan is to use this in the firmware to decide on what value to send based on a config variable same as is possible for temperature.

• degrees P = 259-(259/SG)
• SG = 259/(259-degrees P)

TODO-List:

• Cleaned PCB repo (first version: Einnor)
• Pannelization test (Einnor)
• Reed-switch test/rework (Einnor)
• Footprint Battery Holder with sliding pads (Einnor)
• Footprint D1-Mini 8-pin version (justa) Done by Einnor
• Petling bottles order (justa) Done, 20220608. 10 pieces
• Online-service (ubidots?) uitzoeken/selecteren (sikkepitje)
• Order more parts (Einnor + Justa)
• Test whole setup on a breadboard
• Add gravity scale to firmware (einnor)
• possibly fork firmware repo or create a pull request (einnor)
• setup a mailing list! 😁 (Justa) Done: beernerds@lists.techinc.nl

Ordered stuff

Arrived

• 10 Petling's (justa)
• 2 GY521 Gyro's (justa)
• 1 TP4051 (justa)
• 1 Wemos D1-Mini (justa)
• 2 Battery-holders (justa)
• 5 pcb's (einnor)

In progress

• PCB's (einnor)
• 20 BAT43's (justa)
• 2 SMD-reed-switches (justa)

Iterations

• Version 1, Purple PCB, Techinc Logo