twchart

twchart

twchart is used to document and display sessions using a Thermoworks thermometer that is recorded in the cloud. Using the exported CSV of thermometer data, this program uses Apache ECharts to display other data on top of the graph.

The original inspiration and use-case for this was tracking bread-making since timing and temperature are important aspects of the process. On top of the timeseries temperature data, this is used to track different stages and adhoc notes throughout the process. In order to use it, you should track your notes using this flexible format, then POST to the server after the process is complete.

Notes format

The following format can be used to easily take time-based notes record stages. The server is able to parse this and display on top of a timeseries graph.

[Session Name]
Date: 2006-01-02

[Probe Name] Probe: 1
[Probe Name] Probe: [...]
[Probe Name] Probe: [n]

Note: 3:04PM: [Notes...]
[Stage Name]: 3:04PM
Note: 3:04PM: [Notes...]
[Stage Name]: 3:04PM

Done: 3:04PM

• Dates and times here use Go's formatting conventions
• 3:04PM timestamps can be replaced with elapsed durations (3m, 1h30m, etc.)
• []: brackets above are placeholders for any text. Do not include the brackets. Do not use colons in text
• Everything must be in chronological order
• Notes and stages can happen at any time
• You can have any number of notes and stages

Bread Example

Break-making is easy to track using timestamps since steps are pretty spread out.

Ciabatta
Date: 2025-05-24

Ambient Probe: 1
Oven Probe: 2

Note: 8:10PM: preparing to make biga

Preferment: 8:10PM
Note: 8:13PM: finished mixing biga

Bulk ferment: 7:00AM
Note: 8:00AM: 10 stretch and folds

Final Proof: 9:00AM
Note: 9:00AM: shaped dough

Bake: 10:30AM
Done: 10:55AM

Note: 12:00PM: bread is delicious and crunchy

Coffee Roasting Example

Coffee roasting happens pretty quickly, so it's easier to record durations instead of timestamps.

Coffee
Date: 2025-05-24

Ambient Probe: 1
Bean Probe: 2

Note: 8:00PM: preheat

Drying: 1m
Note: 1m: fan 9, heat 5

Maillard: 4m
Note: 4m: fan 7, heat 7

Development: 7m
Note: 7m: fan 5, heat 6
Note: 7m30s: first crack

Cooling: 8m30s

Done: 10m30s

Installation

go install github.com/calvinmclean/twchart/cmd/twchart@latest

docker pull ghcr.io/calvinmclean/twchart:latest

Usage

Run the server with existing data:

twchart serve --dir data/

This assumes you have a nested directory structure with .txt and .csv files with matching filenames (bread.txt/bread.csv)

See the docker-compose.yml file for an example using docker.

Uploading Data

Here is my process, but something else might work better for you.

1. During baking/roasting/bbqing, record notes in a Notes app
2. When it's done, use a Siri shortcut to make this request:

curl \
  -X POST \
  -H "Content-Type: text/plain" \
  --data-binary "@example.txt" \
  localhost:8080/sessions

1. Download the exported CSV from Thermoworks Cloud and upload to the server with a Siri shortcut making this request:

curl \
  -X POST \
  -H "Content-Type: text/csv" \
  --data-binary "@example.csv" \
  localhost:8080/sessions/upload-csv

• The /upload-csv endpoint will load the CSV data into the most recently-created Session