Turn-key PCB assembly services in prototype quantities or low-volume to mid-volume production runs

Power controller for Raspberry Pi

pic based raspberry pi power controller

Raspberry Pi has a simple power supply solution – via microUSB port. This is great for prototyping but in real applications you would probably like more control. If your end device is battery or solar powered you should implement some king of power monitor-controller. Kevin Sangeelee has been working on Raspberry Pi power controller based on PIC microcontroller. Power controller is connected to Raspberry Pi as I2C slave and has following features: Power the Raspberry Pi off and on with a push-button; Fully shut down the Raspberry Pi on ‘shutdown -h’; Wake-up at a specified time (one-off or periodic); Monitor the supply voltage; Log glitches in the power-supply (e.g. caused by USB device activity); Maintains the time from a CR2032 button cell. Project is still on breadboard and software is under development, but it already shows promising results. Continue reading

Raspberry Pi tells when train leaves

If your time heavily depends on trains it is good idea to have schedule near by. Usually you can get latest departure times on internet. If you travel a lot like Gareth James you would like to have several next times in front of you. Luckily he recently bought a Raspberry Pi and decided to make use of it. And so he started building a nice frame out of 7” LCD display. Instead of making it graphical he added laser printed graphics around screen. USB based WiFi ensures internet connectivity where RasPi scrapes latest departure times from website. Once single button is pressed – three latest times are refreshed. All magic is done with Python script running on Raspberry Pi. It uses Beautiful soup engine to scrape data from website. Continue reading

Audiobook reader for visual impaired

Visual impaired people have limited access to real world good. One of them are books. You cannot pic any and read. Michael happens to have a 90 year grandma who can’t read for same reasons so he decided to make a nice gift for her upcoming birthday. So he came up with audiobook reader device based on Raspberry Pi. The main goal was to make it super duper simple to use. So one button seemed enough for operating. The whole secret lies within. program is written using Python script which takes care of reading audio book from SD card. Following button clicks, remembering last read position and copying new books once USB thumb drive is attached. User only has to click button once to continue reading and click again to pause. For plauing audio, mpd – music player daemon is used which supports multiple formats including MP3, Ogg Vorbis, MP4/AAC, MP2, FLAC, wave and couple more. 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