Yun & Compatible

Details

Written by Sonny Yu

• Bridge Library

Console Pixel example from IDE:

#include <Console.h>
const int ledPin = 13; // the pin that the LED is attached to
char incomingByte;      // a variable to read incoming Console data into
void setup() {
  Bridge.begin();   // Initialize Bridge
  Console.begin();  // Initialize Console
  while (!Console);   // Wait for the Console port to connect
  Console.println("type H or L to turn pin 13 on or off");  
  pinMode(ledPin, OUTPUT); // initialize the LED pin as an output:
}
void loop() {
  // see if there's incoming Console data:
  if (Console.available() > 0) {
    incomingByte = Console.read();  // read the oldest byte in the Console buffer:
    Console.println(incomingByte);
    if (incomingByte == 'H') {
      digitalWrite(ledPin, HIGH);  // if it's a capital H (ASCII 72), turn on the LED:
    }
    if (incomingByte == 'L') {
      digitalWrite(ledPin, LOW);   // if it's an L (ASCII 76) turn off the LED:
    }
  }
}

Test above code:

ssh root@ yourYunsName.local 'telnet localhost 6571'

type "H" will be on, type "L" will be off.

Now we need redirect port 8888 of Arduino Yun ip (i.e. 192.168.0.102) to localhost 6571.

opkg update
opkg install socat

(socat TCP-LISTEN:8888,fork TCP:127.0.0.1:6571) &

Now you should be able access Yun from PC

telnet 192.168.0.102 8888

type "H" will be on, type "L" will be off.

Details

Written by Sonny Yu

• Bridge Library

Install software:

opkg update
opkg install php5  php5-cli
opkg install php5-mod-sockets
opkg install php5-mod-json

Php code:

nano /mnt/sda1/bridge.php

#!/usr/bin/php-cli
<?php
require ("/usr/lib/php/bridge/bridgeclient.class.php");
$firstValue = $argv[1];
$secondValue = $argv[2];
$thirdValue = $argv[3];
$client = new bridgeclient();
$inputfile="/mnt/sda1/input.csv";
$inputstr=file_get_contents($inputfile);
$inputstr="1,2,3";
$client->put("D12",$inputstr);
$outputstr=$firstValue.','.$secondValue.','.$thirdValue;
$outputfile="/mnt/sda1/output.csv";
file_put_contents($outputfile, $outputstr);
?>

chmod 755 /mnt/sda1/bridge.php

ATmega32u4 code:

#include <Process.h>
void setup()
{
  Bridge.begin();
  while (!Serial);     // do nothing until the serial monitor is opened
  Serial.println("Start");
}
void loop()
{
  Process p;
  p.begin("/mnt/sda1/bridge.php");
  p.addParameter("4");
  p.addParameter("5");
  p.addParameter("6");
  p.run();
  char lbuffer[256];
  Bridge.get("D12", lbuffer, 256);
  //Serial.println(lbuffer);
  String str = String(lbuffer);
  int commaIndex = str.indexOf(',');
  int secondCommaIndex = str.indexOf(',', commaIndex + 1); //  Search for the next comma just after the first
  String firstValue = str.substring(0, commaIndex);
  String secondValue = str.substring(commaIndex + 1, secondCommaIndex);
  String thirdValue = str.substring(secondCommaIndex + 1); // To the end of the string
  Serial.println(firstValue);
  Serial.println(secondValue);
  Serial.println(thirdValue);
  delay(1000);
}

Details

Written by Sonny Yu

• Datalog and DB

Memcached is a general-purpose distributed memory caching system. It could delivery 10~20 time speed boost than Mysql.

opkg update 
opkg install memcached
/etc/init.d/memcached  start
/etc/init.d/memcached  enable

opkg update 
opkg install python-openssl 
opkg install distribute 
easy_install python-memcached

nano /mnt/sda1/memcacheyun.py

#!/usr/bin/python
import memcache
mc = memcache.Client(['127.0.0.1:11211'], debug=0)
mc.set("some_key", "Some value")
value = mc.get("some_key")
print value
mc.set("another_key", 3)
mc.delete("another_key")
mc.set("key", "1")   # note that the key used for incr/decr must be a string.
mc.incr("key")
print  mc.get("key")
mc.decr("key")
print  mc.get("key")

root@Arduino:chmod 755 /mnt/sda1/memcacheyun.py

root@Arduino:/mnt/sda1/memcacheyun.py
Some value
None
2
1