Bluetooth: Send
Sending Information Wirelessly from the D1 R32
What it is
The Bluetooth: Send category contains the blocks used to transmit information from the D1 R32 through Bluetooth.
This category should be understood primarily as the outgoing-data side of Bluetooth communication:
D1 R32 → Bluetooth → Connected Device
The information sent might later come from:
- Text
- Variables
- Sensor readings
- Counters
- Calculations
- Program states
Think of Bluetooth: Send as the wireless output channel of the program. The D1 R32 produces information and sends that information to another Bluetooth device.
Fun Guide to Bluetootd Transmission Blocks (Clu-blocks Pro)
Important! Bluetootd blocks let your robot talk to other devices like phones, tablets, or other robots. You can send messages, receive commands, and even check if the connection worked. It’s like giving your robot a walkie-talkie!
| Block | What it does | Dropdown options | What the options mean |
 | Sets up your robot as the controller | — | Central devices scan and connect to others like the boss of the Bluetootd network |
 | Starts searching for nearby devices | — | Finds Bluetootd devices around you like radar |
 | Gets your robot’s Bluetootd ID | — | Useful for identifying your robot or sharing its address |
 | Connects to a device by name | name, MAC Address | - name: connect using device name- MAC Address: connect using unique hardware ID |
 | Sends a message over Bluetootd | — | You can send text, numbers, or commands to another device |
 | Disconnects from Bluetootd | — | Stops the Bluetootd useful for switching modes |
Quick Tips for Students
- Use Central mode to control other devices like a remote.
- Use Peripheral mode to be controlled like a robot waiting for orders.
- Use send + receive to build chat systems, remote controls, or multiplayer games.
- Always check connection status before sending it saves bugs and frustration.
- Use callback functions to make your robot react instantly like a Bluetootd reflex!
1. Bluetooth Communication Direction
Bluetooth communication becomes easier to understand when students first identify the direction of information.
For this category:
SEND = D1 R32 → OTHER DEVICE
Conceptually:
PROGRAM
↓
DATA
↓
BLUETOOTH SEND
↓
WIRELESS COMMUNICATION
↓
CONNECTED DEVICE
This is the opposite direction from Bluetooth Receive:
OTHER DEVICE → BLUETOOTH → D1 R32
2. Sending Text
[ INSERT BLOCK IMAGE HERE: Bluetooth Send Text ]
The simplest information for students to transmit should be text.
For example:
Plain Text
Clu-Block
Conceptually:
"Clu-Block"
↓
Bluetooth Send
↓
Connected Device
This should be the first Bluetooth Send exercise because students can immediately recognize whether the transmitted information arrived correctly.
3. Sending a Variable
Bluetooth becomes significantly more useful when the transmitted information changes while the program is running.
Conceptually:
Variable
↓
Bluetooth Send
↓
Connected Device
For example:
counter
↓
Bluetooth
↓
Remote Device
This establishes an important connection between the Variables and Bluetooth categories.
4. Sending Sensor Information
The next progression should use real sensor data.
For example:
DHT11
↓
Temperature
↓
Bluetooth Send
↓
Connected Device
Or:
Ultrasonic Sensor
↓
Distance
↓
Bluetooth Send
↓
Connected Device
The Bluetooth link therefore changes from simply transmitting a fixed message to carrying live information from the physical world.
5. Raw Data vs. Human-Readable Information
Students should understand that sending a raw number and sending a readable message are different things.
Raw value
Plain Text
23
Human-readable information
Plain Text
Temperature: 23
The second form can be created using the Text category before transmission.
Conceptually:
Sensor
↓
Value
↓
Text Formatting
↓
Bluetooth Send
↓
Connected Device
This reuses a pattern students already learned with Serial communication.
6. Bluetooth + Text
The Text category becomes particularly useful for Bluetooth communication.
For example:
"Distance: [ ]"
Ultrasonic Reading
↓
Formatted String
↓
Bluetooth Send
Conceptually, the remote device receives information with meaning, rather than only a number.
This reinforces the progression:
DATA → TEXT → MESSAGE → TRANSMIT
7. Bluetooth + Serial Port
For your course, I recommend continuing to use the PC Serial connection while Bluetooth is being introduced.
A very useful debugging pattern is:
DATA
↙ ↘
Serial Port Bluetooth Send
↓ ↓
PC Bluetooth Device
This allows students to compare:
What the D1 R32 reports locally to the PC
with:
What the D1 R32 attempts to send wirelessly
This is especially valuable during the first Bluetooth exercises.
8. Send Only When Needed
Once students understand basic transmission, Control can determine when information should be sent.
Conceptually:
Button Pressed?
↓
TRUE
↓
Bluetooth Send
or:
Sensor Changed?
↓
TRUE
↓
Bluetooth Send New Value
This prevents students from thinking that Bluetooth transmission must always happen continuously.
9. Sending Only New Information
For your standard five-exercise progression, Bluetooth Send fits particularly well with COMPARE.
Conceptually:
Current Value
↓
Compare with Previous Value
↓
Changed?
↓
YES
↓
Bluetooth Send
This creates an important communications concept:
Transmit information when it becomes useful, not simply because the program can transmit it.
10. Sending Periodically
Control can also determine the transmission interval.
Conceptually:
Read Sensor
↓
Bluetooth Send
↓
Wait
↓
Read Again
This is useful for measurements such as:
- Temperature
- Humidity
- Distance
- Orientation
- Light level
The exact delay should depend on the exercise rather than being treated as part of Bluetooth itself.
Quick Guide for Students
Do I want information to leave the D1 R32 wirelessly through Bluetooth?
Use:
Bluetooth Send
What should I send first?
A simple text message.
Can the information come from a variable?
Yes, conceptually:
Variable → Bluetooth Send
Can it come from a sensor?
Yes:
Sensor → Bluetooth Send
Should I make sensor data readable?
When useful:
Sensor → Text → Bluetooth Send
How can I check what the program is trying to transmit?
During learning exercises:
Data → Serial Port + Bluetooth
Do I need to send continuously?
Not necessarily.
Use Control and Logic to determine when transmission should occur.
Quick Reference
| Concept | Main Idea |
|---|---|
| Send Direction | D1 R32 → Bluetooth device |
| Fixed Text | Send a simple recognizable message |
| Variable | Send changing program information |
| Sensor | Send measurements |
| Text Formatting | Turn raw values into readable information |
| Serial + Bluetooth | Observe locally while transmitting wirelessly |
| Logic + Send | Send only when a condition is satisfied |
| Compare + Send | Send when information changes |
| Control + Send | Determine when transmission occurs |