Raspberry Pi DIN Rail I/O Interfaces

VP Process Inc has recently released a new series of Raspberry Pi DIN rail mountable “Hardened” interfaces. The first release is the PI-SPI-DIN-RTC-RS485, which is available in three mounting versions: DIN Rail Clips, DIN Rail Enclosure, and PCB Spacers.

The basic specifications for the PI-SPI-DIN-RTC-RS485 are:

  • Power Input: 9 to 24 VDC
  • 5VDC @ 2.5A (Max 3Amp) Power Supply
  • RS485 Output via RJ45 connector and Terminal Block
  • 2 GPIO connectors – 1 internal for Raspberry Pi, 1 external for peripherals
  • 1 PI-SPI-DIN connector (16 Pin) for PI-SPI-DIN series (power, SPI, I2C and 5 Chip Enables)
  • Real Time Clock (I2C) Microchip MCP7940 with Battery Backup

Last week, VP Process added three modules to the series: PI-SPI-DIN-8AI, PI-SPI-DIN-8DI, and PI-SPI-DIN-4KO. Each module of these has 2 x 16 Pin Ribbon Cable sockets and cables and each connector and cable will carry power, I2C bus, SPI bus and 5 GPIO lines for Chip Select. Additionally, each module is available in the three mounting versions mentioned above. Each module takes power from the ribbon cable as a local input power to  5 VDC switching power supply and 3.3 VDC LDO regulator power supply. At the same time, the main module will maintain the 5VDC to keep the Raspberry Pi safe from interfaces loading.

PCB’s mounted with DIN rail clips

The three modules full specifications

PI-SPI-DIN-8AI : An 8 channel 4-20 mA Input interface based on the 12 Bit Microchip MCP3208 A/D converter. Each input can be re-configured (changing resistors and capacitors) as a VDC input or Thermistor input for temperature applications.

PI-SPI-DIN-8DI : An 8 channel Isolated Digital Inptu interface based on the Microchip MCP23S08 I/O Expander. Since this design has 4 addresses, it allows  4 interfaces to connect together for a total of 32 Inputs, all of 1 chip select. The inputs accept up to 24 VDC or 24 VAC, or switch inputs.

PI-SPI-DIN-4KO ; A 4 channel relay output module. Each relay is rated at 2 AAC and is SPDT. The design is based on the Microchip MCP23S08 I/O Expander. Since this design has 4 addresses, it allows 4 interfaces to connect together for a total of 16 relay outputs.

DIN Rail Enclosures

Fortunately, VP Process had perfectly designed PI-SPI-DIN series to suit many industrial applications by making the designs industrial grade, with adding terminal blocks and enclosures. Furthermore, a new module of the same series is coming soon, PI-SPI-DIN-4AO; a 4 channel analog 4-20mA output module.

Finally, the main module is available for $48, where the remaining modules cost $33 each. More details are available at this page.

Source: WidgetLords Electronics

Micropower, Rail-to-Rail, 300kHz Op Amp with Shutdown in tiny package

Op Amp Consumes Only 4.5µA and Offers 300kHz BW in 0.73mm x 1.07mm WLP and SOT-23 package.

The MAX40006 op amp features a maximized ratio of gain bandwidth (GBW) to supply current and is ideal for battery-powered applications such as handsets, tablets, notebooks, and portable medical equipment. This CMOS op amp features an ultra-low input-bias current of 1pA, rail-to-rail input and output, low supply current of 4.5µA, and operates from a single 1.7V to 5.5V supply.

Micropower, Rail-to-Rail, 300kHz Op Amp with Shutdown in tiny package – [Link]

E-Mosquito takes sample of your Blood to Keep You Healthy

e-Mosquito is a fully autonomous device pre-programmed to “bite” one’s skin at various times during the day to monitor blood glucose levels. [via]

The worst part of getting a shot or having your blood drawn is certainly the anticipation. As reported on IEEE Spectrum, researchers at the University of Calgary in Canada have been working on a fully autonomous testing device that can prick diabetes patients for blood testing purposes at unanticipated times, hopefully alleviating this dread.

E-Mosquito takes sample of your Blood to Keep You Healthy – [Link]

Plotting Pricing Trends from Octopart Data

Sanket Gupta @  octopart.com tipped us with his latest article on how to plot pricing trends of electronic parts using Octopart’s data. He writes:

Before you search for specific MPNs, it’s useful to understand broad trends in electronic component pricing and availability to save time and money. At Octopart, we manage information of more than 40 million electronic parts, so we are uniquely positioned to aggregate the part data information and find interesting pricing trends. Electronic data is complex —every part typically is offered by multiple distributors with different quantities in stock and pricing at different price breaks — but if we aggregate all these sources, we can see that interesting trends appear.

Plotting Pricing Trends from Octopart Data – [Link]

Air Quality Sensors on tindie.com

Pesky Products @ tindie.com writes:

This is a small (17.9 mm x 10.3 mm) breakout board with Bosch’s BME280 pressure, temperature, and humidity sensor as well as AMS’ CCS811 digital gas sensor. The sensors work in concert to provide a complete measurement via I2C register reads of indoor air quality including temperature- and humidity-compensated estimates of equivalent CO2 concentration in parts per million (400 – 8192 ppm) and volatile organic chemical concentration in parts per billion (0 – 1187 ppb).

Air Quality Sensors on tindie.com – [Link]

Lowest power magnetic switch uses nanoamps

Crocus Technology is introducing its CT832 Digital Magnetic Switch, in the CT83X series, a multi- function switching device with high sensitivity, reliability and new lows in power consumption, that it positions as the industry’s lowest power consuming switch.

Lowest power magnetic switch uses nanoamps – [Link]

Linear applies switched-capacitor step-down topology for inductor-less DC/DC

Graham Prophet @ eedesignnewseurope.com discuss about the new Linear’s step-down inductor-less controller.
LTC7820 is, a high power fixed ratio charge pump DC/DC controller that eliminates the power inductor in a non-isolated intermediate bus converter, allowing up to a 50% reduction in circuit size and up to 4000 W/in³ power density. The 72V fixed-ratio DC/DC controller can deliver 500W. – See more at: http://www.eedesignnewseurope.com/news/linear-applies-switched-capacitor-step-down-topology-inductor-less-dcdc#sthash.pJcu7NoB.dpuf

SUNY Polytechnic Creates 3-in-1 Device That Can Be A Diode, A MOSFET And A BJT

In a recently published study, a team of researchers at SUNY Polytechnic Institute in Albany, New York, has suggested that combining multiple functions in a single semiconductor device can significantly improve device’s functionality and efficiency.

Nowadays, the semiconductor industry is striving to scale down the device dimensions in order to fit more transistors onto a computer chip and thus improve the speed and efficiency of the devices. According to Moore’s law, the number of transistors on a computer chip cannot exponentially increase forever. For this reason, scientists are trying to find other ways to improve semiconductor technologies.

To demonstrate the new technology which can be an alternative to Moore’s law, the researchers of SUNY Polytechnic designed and fabricated a reconfigurable device that can be a p-n diode (which functions as a rectifier), a MOSFET (for switching), and a bipolar junction transistor (or BJT, for current amplification). Though these three devices can be fabricated individually in modern semiconductor fabrication plants, it often becomes very complex if they are to be combined.

reconfigurable 3-in-1 semiconductor device
the reconfigurable 3-in-1 semiconductor device

Ji Ung Lee at the SUNY Polytechnic Institute said,

We are able to demonstrate the three most important semiconductor devices (p-n diode, MOSFET, and BJT) using a single reconfigurable device. We can form a single device that can perform the functions of all three devices.

The multitasking device is made of 2-D tungsten diselenide (WSe2), a new transition metal dichalcogenide semiconductor. This class of materials is special as the bandgap is tunable by varying the thickness of the material. It is a direct bandgap while in single layer form.

Another challenge was to find a suitable doping technique as WSe2 lacks one being a new material. So, to integrate multiple functions into a single device, the researchers developed a completely new doping method. By doping, the researchers could obtain properties such as ambipolar conduction, which is the ability to conduct both electrons and holes under different conditions. Lee said,

Instead of using traditional semiconductor fabrication techniques that can only form fixed devices, we use gates to dope.

These gates can control which carriers (electrons or holes) should flow through the semiconductor. In this way, the ambipolar conduction is achieved. The ability to dynamically change the carriers allows the reconfigurable device to perform multiple functions. Another advantage of using gates in doping is, it saves overall area and enable more efficient computing. As consequence, the reconfigurable device can potentially implement certain logic functions more compactly and efficiently.

In future, researchers plan to investigate the applications of this new technology and want to enhance its efficiency further. As Lee said,

We hope to build complex computer circuits with fewer device elements than those using the current semiconductor fabrication process. This will demonstrate the scalability of our device for the post-CMOS era.

Twiz – Tiny Wireless IMUs

Tiny Wireless IMUs – 100% open & autonomous 9DoF motion sensor using BLE to control anything from your [objects] motion ! by Drix @ hackaday.io:

We looked for tiny, autonomous, easy to use, and 9 Degrees of Freedom IMU, but none of the available wireless motion sensors were affordable enough to really unlock creativity, so we built one.

Twiz – Tiny Wireless IMUs – [Link]

Samba : Set Up Your Raspberry Pi As A Local Network File Server

Samba is the Linux implementation of the SMB/CIFS file sharing standard used by Windows PCs and Apple computers and widely supported by media streamers, gaming consoles, and mobile apps. In this tutorial, you will learn how to use a Raspberry Pi as a file server where you can save backups and share files with all the other computers on your network using Samba.

You need the following things for this tutorial:

  • A keyboard (Wired or wireless)
  • A mouse (Wired or wireless)
  • Raspberry Pi (Model 3B is recommended)
  • A 32GB (or smaller) micro SD card
  • Internet connection (Only to download Samba)

The SD card must have a reasonable amount of free storage space without requiring any extra steps to make it accessible. However, if you want extra storage, simply mount a large USB drive and create a Samba entry for it. If you want to keep your Samba file server compact and portable, install Raspbian on a 128Gb or 256GB SD card. Before purchasing, check online whether the SD card is fully compatible with Raspberry Pi or not.

Install Samba

Samba is available in Raspbian’s standard software repositories. Update your repository index, make sure that the operating system is fully updated, and install Samba using apt-get. Open a Terminal and type:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install samba samba-common-bin

The download and installation process will start and it will take a while depending on your internet speed.

Create A Shared Directory

Now you need to create a shared directory that will be accessible by other PCs/mobiles connected to the same network. You can put it anywhere, but in this tutorial, it will be at the top level of the root file system of the Pi’s microSD card. Type the following command:

sudo mkdir -m 1777 /share

To help prevent the directory from being unintentionally deleted, the above command sets the sticky bit (1) and gives everyone read/write/execute (777) permissions on the shared directory.

Configure Samba

In this step, edit the smb.conf  file to configure Samba to share the selected directory and allow users to perform various actions like read, write etc. Open the smb.conf file using the following command:

sudo leafpad /etc/samba/smb.conf

You need to add the following entry:

Comment = Pi shared folder
Path = /share
Browseable = yes
Writeable = Yes
only guest = no
create mask = 0777
directory mask = 0777
Public = yes
Guest ok = yes
Configure Samba On Raspberry Pi
Configure Samba On Raspberry Pi

As per the above configuration, anyone can read, write, and execute files in the shared directory, either by logging in as a Samba user or as a guest. Just omit the guest ok = yes line if you don’t want to allow guests. To share a larger external hard disk, simply create a smb.conf entry for the path you want to share across the network (here the external hard disk).

Create A User & Start Samba

Everything is configured and now it’s time to create a user. To set up a password for the user, enter the following command:

sudo smbpasswd -a pi

Then set a password as prompted. It’s recommended that the password should be different from your Pi’s login password. Finally, restart the Samba and set it to start automatically when the Raspberry Pi starts up. Enter the following command:

sudo /etc/init.d/samba restart

Once you’ve made sure that you can locate your shared folder on the network, you can safely disconnect the mouse, monitor, and keyboard from your Pi and just leave it running as a headless file server.