Blues Wireless

The note-tinygo Go library for communicating with Blues Wireless Notecard via serial or I²C.

This library allows you to control a Notecard by coding in Go for the TinyGo platform. Your program may configure Notecard and send Notes to Notehub.io.

See also:

• note-c for C bindings
• note-python for Python bindings

Installing

For all releases, we have compiled the notecard utility for different OS and architectures here. If you don't see your OS and architecture supported, please file an issue and we'll add it to new releases.

Dependencies

• Install tinygo and the tinygo tools (here)

Example

// Example that uses the cellular Blues Wireless Notecard to send data to the notehub.io
// routing service, then routing it through to your own service in JSON on a REST endpoint.

package main

import (
    "fmt"
    "machine"
    "time"

    tinynote "github.com/blues/note-tinygo"
)

// Your Notehub project's ProductUID (so the notecard knows where to send its data)
const productUID = "net.ozzie.ray:test"

// Tinygo's main program
func main() {

    // Use default configuration of I2C
    machine.I2C0.Configure(machine.I2CConfig{})

    // Create a function for this machine type that performs I2C I/O
    i2cTxFn := func(addr uint16, wb []byte, rb []byte) (err error) {
        return machine.I2C0.Tx(addr, wb, rb)
    }

    // Open an I2C channel to the Notecard, supplying the I2C I/O function
    notecard, err := tinynote.OpenI2C(tinynote.DefaultI2CAddress, i2cTxFn)
    if err != nil {
        fmt.Printf("error opening notecard i2c port: %s\n", err)
        return
    }

    // Enable trace output so we can visualize requests/responses
    notecard.DebugOutput(true)

    // Configure the Notecard and set it to auto-provision to your project
    req := tinynote.NewRequest("hub.set")
    req["product"] = productUID // which notehub project we're using
    req["mode"] = "continuous"  // stay online continuously
    req["outbound"] = 60        // how often (mins) to auto-sync if pending data
    err = notecard.Request(req)
    if err != nil {
        fmt.Printf("%s: %s\n", req["req"], err)
    }

    // Enter a loop that sends data to the Notehub repeatedly. Data on the notecard
    // is stored within a user-defined JSON 'body', carried within an envelope called
    // a 'note' that is automatically tagged with time and location metadata.
    for i := 0; ; i++ {
        time.Sleep(time.Second * 10)

        req := tinynote.NewRequest("note.add") // 'add a note' transaction

        // Create 'body' by using Golang's standard container for a JSON data
        // structure, which is a map of fieldname-indexed data of any type.
        // This 'body' is completely user-defined, and would presumably contain
        // you sensor data.
        body := map[string]interface{}{}
        body["test1"] = i
        body["test2"] = float64(i) + float64(i)*0.2
        body["test3"] = fmt.Sprintf("0x%04x", i)
        body["test5"] = (i & 1) == 0
        body["test6"] = map[string]interface{}{"hello": "world"}

        req["body"] = body // add the user-defined body to the note
        req["sync"] = true // for this test, sync to notehub immediately

        // Send request to notecard and check the response for errors
        rsp, err := notecard.RequestResponse(req)
        if tinynote.IsError(err, rsp) {
            fmt.Printf("%s: %s\n", req["req"], tinynote.ErrorString(err, rsp))
        }

    }

}