# fermentord

Control the temperature of your fermentation process.

# Integrations

* NATS
* Prometheus
* Sentry

# Epics

## Heater/Cooler

| Persona  | Description                                                                    |
|----------|--------------------------------------------------------------------------------|
| Brewer   | The person responsible for the wort and the fermentation process               |
| Operator | The person responsible for the fermentation tank and the system controlling it |

*As a brewer I need to maintain the wort at a specific temperature so that my fermentation process is predictable*
*As an operator I need an alert if the system can't maintain the temperature, so that I may correct the problem*

## Ambient temperature

* Ambient temperature
* Case temperature
* Wort temperature
* Wort gravity

# User stories

## Acceptance criteria

* Given the wort is at or above the requested temperature and the heater is running then stop the heater
* Given the wort is above the requested temperature and the heater is not running then start the cooler
* Given the wort is above the requested temperature

* Given the wort is too cold and the cooler is running then stop the cooler
* Given the wort is too cold and the cooler is not running then start the heater

* Given the cooler is running
* Given the cooler is running when then the heater may not start
* Given the heater is running then the cooler may not start
* Given the temperature is 

# Data logging

* Ambient temperature
* Case temperature
* Wort temperature
* Wort gravity

* Data is stored in sqlite3
* Data is scraped and stored in PostgreSQL
* Data is removed from sqlite3 when confirmed in PostgreSQL

# Metrics

Prometheus metrics

* Ambient temperature
* Chamber temperature
* Wort temperature
* Wort gravity
* Heater state
* Cooler state
* Tank pressure

# Drivers

On the Raspberry Pi you'll need to add `dtoverlay=w1-gpio` (for regular
connection) or `dtoverlay=w1-gpio,pullup="y"` (for parasitic connection)
to your /boot/config.txt. The default data pin is GPIO4, but that can be
changed from 4 to x with `dtoverlay=w1-gpio,gpiopin=x`.

```bash
echo dtoverlay=w1-gpio,gpiopin=4,pullup=0 >> /boot/config.txt

modprobe wire
modprobe w1-gpio
modprobe w1-therm
```

# Build

A Raspberry Pi 1 is used, so we compile for ARMv6.

```bash
cd cmd/fermentord
GOARCH=arm GOARM=6 GOOS=linux go build
```