Editor in depth
How the editor's wiring, node labels, presets, config nodes and node status work.
Wiring
Every port has a type: int, number, bool, string, bytes or any. The editor refuses a wire between
types that don't fit. What each input type accepts:
| Input | Accepts wires from |
|---|---|
any |
any output |
bool |
any output. The value is tested with Python's bool(). |
number |
number, int, string |
int |
int, string |
string |
string |
bytes |
bytes, any |
A string that isn't a number fails on the board when it reaches a number or int input, with a NODE_ERROR.
An any output, such as the output of a function node, connects only to any, bool and
bytes inputs.
An input can take any number of wires. The node runs once for each message that arrives, whichever wire it came on. An output can feed any number of inputs.
Giving a node a flow label
Every node has a flow label field at the top of its property panel. Type something, say Fire!, and the canvas
shows it instead of the node's name. Leave it blank to show the name again. Console messages and errors that name
the node use the flow label too.
A gui button also has a board label, the text drawn on the button. If the board label is blank, the button
shows the flow label.
Presets
A preset is a named set of property values, such as the pins and size of one display panel. display spi,
display i2c and the Touch panel config have a preset menu at the top of their property panel:
- Pick a preset to copy its values into the node's properties.
- Click 💾 to save the current values as a preset, under a name you choose.
- Click ↻ to read the preset files again.
Applying a preset copies the values once. Later changes to the node or the preset don't affect each other.
Each preset is a JSON file in ~/.thingstudio/presets/<node type>/, which you can also write by hand. A file that
isn't valid JSON appears in the menu disabled, with the file named. See
The Thingstudio folder.
Config nodes
A config node holds settings that several nodes share. A node's property panel has a field to pick one; ✎ edits it and + makes a new one. The config nodes are:
- WiFi: a saved credential and a security mode: password, open, or unmanaged.
- MQTT Broker: a saved credential holding the host, port and optional username and password.
- I2C bus: the bus number, SCL and SDA pins, and frequency. See I2C bus.
- Touch panel: the touch controller, its I2C bus and address, and its size and orientation. See Touch panels.
The WiFi and MQTT Broker configs hold only the name of a saved credential. The SSID, passwords and broker address
are saved by name in ~/.thingstudio/credentials/, not in the flow file, so a flow you share or commit holds no
secrets. Two flows that use the same credential share its values: edit it once and both change. Pick, edit or add a
credential from the config's credential field. See The Thingstudio folder.
A flow has one WiFi network. Every node that uses WiFi has a WiFi field, and they all show the same setting:
change it on one and it changes on all. A flow doesn't need a wifi status node to use the network.
Node status
Some nodes show a colored dot and a line of text under the node while the editor is connected to the board:
| Dot | Meaning |
|---|---|
| Green | connected |
| Amber | connecting |
| Gray | disconnected |
| Red | error |
The dot shows what the board reports, not the editor's guess. It appears once the running flow first reports, and clears on every deploy until the new flow reports.
The nodes with a status are wifi status, mqtt publish, mqtt subscribe, i2c device, bme280, touch, and a
gui screen with a touch panel.
Notes
The Notes panel on the right is free text about the flow: what it does, what to wire up, how to use it. It's saved in the flow file, and opens by itself when you open a flow that has notes. File → New flow clears it.