Controlling a stepper with raspberrypi gpio pins

Raspberry RASPBRRY-MODB-512M Mainboard Sockel (ARM 1176JZF-S, 2x USB 2.0, 1x HDMI)

First of all, you need the wiringPi library from https://projects.drogon.net/raspberry-pi/wiringpi/download-and-install/
Once installed, there is a new command gpio which can be used as a non-root user to control the GPIO pins.

I took a schmalzhaus easydriver stepper shield, controlled with a little shell script.

circuit layout:

My stepper has 1,8° = 200 Steps for 360°
GPIO pin 23 controlls the steps, one high peak per step,
GPIO pin 24 controlls the direction

30 times clockwise and counterclockwise Rounds:

shell script:

#!/bin/sh
pause=0.001
gpio -g mode 23 out
gpio -g mode 24 out


for i in $(seq 30); do

echo round $i starts:
sleep 1

gpio -g write 24 1
for i in $(seq 200); do
  echo $i
  gpio -g write 23 1
  sleep $pause
  gpio -g write 23 0
  sleep $pause
done
sleep 1
gpio -g write 24 0
for i in $(seq 200); do
  echo $i
  gpio -g write 23 1
  sleep $pause
  gpio -g write 23 0
  sleep $pause
done
done

Arduino to google docs

Adafruit Waveboard Sample Rate fun

Changing the sample rate with Arduino UNO and the Adafruit Waveboardshield makes fun:

Here the things you need:

Libary AFWave_18-02-09

Arduino sketch

instead of the potentiometer you can use any analog value, fun fun fun

Pachube - Arduino Ethernetshield with a DS18S20 Temeprature sensor

Test of a Arduino Ethernetshield with a DS18S20 Temeprature sensor:

Here is my feed on pachube.com : https://pachube.com/feeds/44942

There you can simple and free log any data, like Temperature.

Here is the code for Arduino and the new Pachube lib:

#include <SPI.h> #include <Ethernet.h> #include <Pachube.h> #include <OneWire.h> OneWire ds(8); // on pin 8 byte mac[] = {0x90, 0xA2, 0xDA, 0x00, 0x10, 0x8f}; char apiKey[] = "YOURKEYHEREYOURKEYHEREYOURKEYHEREYOURKEYHEREYOURKEYHEREYOURKEYHERE"; long feedId = 44942; char datastreamId[] = "stisi"; long prevMillis = 0; float celsius; PachubeClient client = PachubeClient(apiKey); void setup() { Serial.begin(9600); client.connectWithMac(mac); } void loop() { unsigned long curMillis = millis(); if(curMillis - prevMillis > 10000) { byte i; byte present = 0; byte type_s; byte data[12]; byte addr[8]; if ( !ds.search(addr)) { ds.reset_search(); delay(250); return; } Serial.println(); // the first ROM byte indicates which chip switch (addr[0]) { case 0x10: Serial.println(" Chip = DS18S20"); // or old DS1820 type_s = 1; break; case 0x28: Serial.println(" Chip = DS18B20"); type_s = 0; break; case 0x22: Serial.println(" Chip = DS1822"); type_s = 0; break; default: Serial.println("Device is not a DS18x20 family device."); return; } ds.reset(); ds.select(addr); ds.write(0x44,1); // start conversion, with parasite power on at the end delay(1000); // maybe 750ms is enough, maybe not // we might do a ds.depower() here, but the reset will take care of it. present = ds.reset(); ds.select(addr); ds.write(0xBE); // Read Scratchpad for ( i = 0; i < 9; i++) { // we need 9 bytes data[i] = ds.read(); } // convert the data to actual temperature unsigned int raw = (data[1] << 8) | data[0]; if (type_s) { raw = raw << 3; // 9 bit resolution default if (data[7] == 0x10) { // count remain gives full 12 bit resolution raw = (raw & 0xFFF0) + 12 - data[6]; } } else { byte cfg = (data[4] & 0x60); if (cfg == 0x00) raw = raw << 3; // 9 bit resolution, 93.75 ms else if (cfg == 0x20) raw = raw << 2; // 10 bit res, 187.5 ms else if (cfg == 0x40) raw = raw << 1; // 11 bit res, 375 ms // default is 12 bit resolution, 750 ms conversion time } celsius = (float)raw / 16.0; Serial.print("Temperatur = "); Serial.print(celsius); Serial.print(" Celsius, "); //ende tempmessung prevMillis = curMillis; } else{ // send to the Pachube client client.updateFeed(feedId, datastreamId, celsius); } }