Raspberry Pi advice machine

A good advice sometimes is all you need. What if there are no fortune tellers around… then advice machine might help. Nick Johnson spent some time while building a neat advice machine based on Raspberry Pi. It is well designed and enclosed in to laser cut plywood box. First of all you need to insert coin. The more money you put the better advice you get. After all coins are spent, press a button and advice is printed with small thermal printer from Sparkfun. All status messages are visible on standard 2×16 LCD. So what advices you may expect there? These may be a simple quotations, more expensive may be deeper fortunes or even jokes. This is great devices to collect donations. Continue reading

QR code based door lock with BeagleBone

Jeremy Blum published his interesting idea of opening doors. Instead using locks or RFID swipe cards he suggests using QR-code based entry system. Reading QR codes requires camera. BeagleBone is powerful enough and is based on Linux so programming and interfacing is pretty easy. [youtube https://www.youtube.com/watch?v=C8ZT-4VX1BE&w=468] Suggested system works as follows. No matter where this system is installed, users are registered within web interface. After user is approved he gets QR code via email that can be printed and used. This system seems to be weak from attacks. QR codes can be photographed from distance. But for less secured areas might be a fun to use. Continue reading

Expanding Raspberry Pi with more I/Os and servo outputs

Rasp Pi comes with I/O header what makes hackers and tinkers do lots of fun within Linux. But when you need do more specific interfacing like serial RS232 or RS485, or Servo control, it takes some preparation. To make things look more easier an expansion board called Raspy Juice was designed that holds serial RS232 and RS485 connectors and level convertors. Additionally there are four RC servo ports. All this wouldn’t be so easy with AVR Atmega168A microcontroller on it. It interfaces to Raspberry Pi as i2C slave. After using several pins for above functions there are sill few left for general purpose. SO why not use them for analog input that are so welcome in Ras Pi. If you’re wandering what other expansion boards are already made then check out this nice list – might find something you need. Continue reading

Web based IO control for Raspberry Pi

Raspberry Pi is a cool low budget Linux platform. It can be used as small computer or/and project board with several available interfaces and I/O pins. Eric has been working on WebIOPi project which allows controlling RasPi I/O pins using browser. All you need is to install small application in to Raspberry Pi and you can access pins for reading and writing using any browser on a network including smartphones. User interface is pretty simple but there is a CSS included where anyone can make modifications to make it look unique. You can also build a client using REST API. Project is still in early stage and only supports simple GPIO operations. But there are plans to add UART, I2C SPI support and more. Continue reading

Turning Raspberry PI in to PIC programmer

Raspberry Pi is pretty popular Linux on a small board solution. It can do lots of stuff you can think off, so Giorgio Vazzana decided to build a PIC programmer. The RasPi software (called rpp) is written for GCC without any external library. So it can be compiled by running make command. The more hustle there is with programmer physical interface as PIC requires high voltage (12V) supply in programming mode and 5V to drive logic. So it needs additional hardware attached to Raspberry Pi, because it provides only 3.3V. Currently programmer supports only 11 PIC16 chips without ICSP support. Hopefully this project will evolve in to more usable. Continue reading

Raspberry Pi logs solar energy harvesting

Brian has been using solar panels and solar collectors in his house for some time. Earlier he used an Arduino and IOIO board for data logging. But lately he moved to well known Raspberry Pi platform that gives much more space to work with. Still using a Raspberry PI for such task is quite an overkill but its fun indeed. It pulls sensor data from various sensors including i2C Microchip MCP980, 1-Wire DS18B20 on solar collector; ACS712 current sensor in low voltage part and mains current using Elkor i-Snail-VC transducer. Raspberry Pi has MCP3428 16-bit ADC on-board to read transducer values. Since Pi board runs Linux it is obvious that all hard job is done using Python. Brian even made a custom DC-DC power supply that fits nicely on top of Raspberry Pi board. His future plans are to push data in to MySQL instead of using direct HTTP GET upload method. Continue reading