PiPlanter | Graphing With PHP

February 12, 2013 / Leave a comment

Again, short post. This php code:

<?php
session_start();
require_once "/srv/www/lib/pChart/class/pDraw.class.php";
require_once "/srv/www/lib/pChart/class/pImage.class.php";
require_once "/srv/www/lib/pChart/class/pData.class.php";

$squareSeries = array();
$cubeSeries = array();
$fourthSeries = array();

for ($i = 0; $i <= 4; $i++){ 	$squareSeries[$i] = pow($i,2); 	$cubeSeries[$i] = pow($i,3); 	$fourthSeries[$i] = pow($i, 4); } $myPowersData = new pData(); $myPowersData -> addPoints($squareSeries,"Square");
$myPowersData -> addPoints($cubeSeries,"Cube");
$myPowersData -> addPoints($fourthSeries,"Fourth");

$myPowersData-> setPalette("Square",
	array("R" => 240, "G" => 16, "B" => 16, "Alpha" => 100));
$myPowersData-> setPalette("Cube",
	array("R" => 16, "G" => 240, "B" => 16, "Alpha" => 100));
$myPowersData-> setPalette("Forth",
	array("R" => 16, "G" => 16, "B" => 240, "Alpha" => 100));

$myPowersImage = new pImage(500,300, $myPowersData);
$myPowersImage -> setFontProperties(array(
	"FontName" => "/srv/www/lib/pChart/fonts/verdana.ttf",
	"FontSize" => 12));

$myPowersImage->setGraphArea(40,40, 460,260);
$myPowersImage->drawScale();

$myPowersImage->drawLineChart();
header("Content-Type: image/png");
$myPowersImage->Render(null);

will produce this graph:

I learned this using this resource:

http://phpmaster.com/charting-with-pchart/

PiPlanter | Interfacing an ADC, Python, and MySQL [Documentation]

February 12, 2013 / 2 Comments

As this post is more of an update, I won’t be adding any explanations, just giving the python code.

This will read 3 values from the adc and put them into the database “adc_database”. It will put them in the table “adc_input_data_4” in the columns “Channel_1″,”Channel_2” and “Channel_3” respectively.

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import spidev
import time
import MySQLdb
import sys
import RPi.GPIO as GPIO

pin = 26

GPIO.setmode(GPIO.BOARD)
GPIO.setup(pin, GPIO.OUT)

con = MySQLdb.connect('localhost','adc_user','adc_user_pass','adc_database');
cursor = con.cursor()

spi = spidev.SpiDev()
spi.open(0, 0)
count = 0
maxcyclenumber = 5

tmp = "derp"

def readadc(adcnum):
# read SPI data from MCP3008 chip, 8 possible adc's (0 thru 7)
    if adcnum > 7 or adcnum < 0:
        return -1
    r = spi.xfer2([1, 8 + adcnum << 4, 0])
    adcout = ((r[1] & 3) << 8) + r[2]
    return adcout
    

for _ in range(maxcyclenumber):
	
	GPIO.output(pin,True)
	cursor.execute("INSERT INTO adc_input_data_4(Channel_1,Channel_2,Channel_3) VALUES('%s','%s','%s')",(readadc(0),readadc(1),readadc(2)) )
	GPIO.output(pin,False)
	
	count = count+1
	print count
	time.sleep (1)
	
if count == maxcyclenumber:
	GPIO.cleanup()
	con.commit()
	con.close()

There you go, bigger post coming later tonight.

Basic Wetness Sensor

November 22, 2012 / 1 Comment

So I’ve had the idea for a while to try and automate the growing of plants so I need to be able to tell if something’s wet or not. Here’s a video:

Basically the hookup process is that of a regular analog sensor with this in it’s place. There’s a 10k pullup resistor as the voltage divider.

Here’s the source for the Arduino.

int write1;
int writeval;

void setup(){
 Serial.begin(9600);
 pinMode(3, OUTPUT);
}

void loop(){
 Serial.println(analogRead(0));
 write1 = map(analogRead(0), 0, 1023, 0, 100);
 writeval = map(write1, 0, 100, 0, 1023);
 analogWrite(3, writeval);
 delay(100);
}

That’s pretty complex but I was trying to make the light changes more drastic so it would show up in the video better.

Here are some pictures of the build process: