Project Logs

Collapse

• Good, Bad, and luckily no ugly

  Anool Mahidharia • 10/29/2015 at 17:55 • 2 comments

  We have bad news and good news !

  First the Bad.

  We choose to use the Atmel SAM R21 to power the HaDge. It's one of the new breed of devices consisting of an ARM Cortex-M0 MCU + IEEE 802.15.4 Wireless radio bundled together. This was exciting since we could pack a lot of punch in the HaDge hardware. [Michele Perla] had earlier built a project called JACK – Just Another Cortex Kit – based on the Atmel SAM D21. This device was similar to the R21, but without the Radio. He decided to build a prototype R21 board based on the JACK design. This was the HACK – HackAday Cortex Kit. Building this would have allowed us to get it in the hands of the software team, while the hardware folks worked on the real HaDge layout. [Michele] finished the HACK layout some time ago, and we were looking for help with checking the Antenna design. We asked Atmel for help with verifying the layout. That's when we had the facepalm moment. They asked us - “What about FCC certification?” Since we plan to build the badges in quantities of a few hundred at the very least, it's obvious we cannot escape from FCC certification. A design based around the R21 is ruled out. We'll need to use an off-the-shelf radio module which is already FCC certified. Sigh.

  Now the good news.

  This is a setback in terms of time, and effort put in by [Michele]. But beyond that, we're good to go back to the drawing board and start afresh. First off, we decided to revert back to the Atmel D21. It's a fairly decent MCU, and being from Atmel, there's a fairly robust tool chain available that a lot of people are familiar with. For the Radio, we looked at some of these available options :

  • https://www.anaren.com/air/products/24ghz-solutions
  • http://www.nordicsemi.com/eng/Products/2.4GHz-RF
  • https://www.adafruit.com/products/2471
  • http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en535967

  The last one from Microchip looks quite promising. But we're open for better and cheaper suggestions, so please chip in with your comments.

• some thoughts on the BoM

  Anool Mahidharia • 08/30/2015 at 18:21 • 6 comments

  So, over on the group messaging channel, we have been discussing, a lot, about the BoM - the Bill of Materials before we even bring out the notepads to make the schematic sketches. This is important because it helps us to make sure our design will meet one of the main criteria we set forth in the beginning - cost. Here's what I've distilled from all the chatter :

  Microcontroller : After quite a bit of discussion, we finally zeroed in on the Atmel ATSAMR21 - a microcontroller + radio rolled in one. A 32 bit ARM Cortex M0 with a 2.4GHz transreceiver.

  Battery : A 3.7V, approx. 2500mAh battery will power the badge. Estimates tell us the display will gulp about 100mA, and the rest of the circuit an equal amount. This is erring on the higher side a lot, so the battery can be expected to last at least 10 hours on a single charge. Enough to last a whole day before needing a re-charge.

  Display : We looked at e-paper and Sharp memory displays, but will most likely settle for a 2.4 inch, color TFT LCD display with a 320x240 pixel resolution.

  These three are the big ticket items on the BoM. Choosing the cheaper LCD makes sure we limit the BoM cost to around $35. With the e-paper and Sharp Displays, we touch almost $50 on the BoM.

  Besides the above three, the Badge will likely have the following parts :

  Several WS2812B RGB smart LEDs

  A speaker, low profile, capable of playing some low fidelity audio

  Capacitive touch buttons formed using the Hackaday Logo

  A pair of IR transmit and Receive LEDs. These could have several applications - interacting with other badges, allowing programming of badges using blinking clock and data squares on a host computer etc.

  A Li-Po charging regulator

  A buck regulator to produce the 3.3V required for most of the board, and another 5V boost regulator to run the RGB LED's and the OTG USB connection.

  Connectors - Mini or Micro USB, JST for the Li-Po, headers for programming etc.

  Footprints and headers for mounting stuff like LDR / Photo Diode (ambient light sensing), Acelerometer (pedo meter), headers for HC-05, ESP8266, GPS, etc.

  Add in passive components, the PCB, Assembly, Testing and related stuff, and we are pretty close to the $30 sweet spot.

  You'll find the "work in progress" BoM at this spreadsheet link.
  

  Any thoughts, chime in with comments below.
  

• Git repositories created - Hardware, Firmware, Software

  Anool Mahidharia • 08/24/2015 at 11:02 • 0 comments

  We've created three separate repositories for HaDge.

  HaDge_HW : for hardware team. Hosts design files - PCB, Mech Cad etc.

  HaDge_FW : for firmware team.

  HaDge_SW : for software team. We foresee we will need some kind of a web interface, for programming the badges (storing hacker ID's, messaging etc.)

  For Hardware, let me know if you are interested to contribute, and I'll add you to the team. We will be using Kicad for the board layout, and most likely FreeCad for the mechanical (housing, 3D printed parts, etc), so if you're good at these, chime in.

  For Firmware and Software, let me know if anyone is willing to take lead of the team. My experience is in Hardware, so it would be more appropriate for someone with the right background to lead the firmware and software development. Send me a private message.

• We have a name - now let's get crackin'

  Anool Mahidharia • 08/23/2015 at 11:47 • 0 comments

  So, based on the poll for names on this spreadsheet , we have a candidate name - The HaDge. This is provisional, unless everyone agrees and it catches on. I'll set up a Git repo soon. There has been some discussion about budget, deadline, features and specifications, and such. Let's lay down the ground rules :

  BUDGET

  Let's start with an arbitrary budget of $35 for each HaDge. This should cover most component scenarios. We'll revise it once features and specifications are frozen. Hackaday will be underwriting the expenses towards hardware development.

  DEADLINE

  This is tricky, so we'll set short term goals for specifics, and a long term one for overall completion of about 6 months. Let's see how things progress. One step at a time

  FEATURES AND SPECIFICATIONS

  Based on the stuff listed on the spreadsheet, we need to build up a working Bill of Materials so we can start some initial work. This is our next deadline. By the end of next week, Aug 30th, we need to fix this.

  TEAMS

  While this is a community project, it may not be too practical to have a very large development team. We're going to break it up in to Hardware, Firmware and Software. Add your name and your expertise on the spreadsheet. We'll pick up a lean team based on expertise and (time) availability. Deadline for Team formation is Aug 30th.

  Let's keep the momentum going !
  

• Getting started - we need a name for the Badge

  Anool Mahidharia • 08/17/2015 at 17:49 • 12 comments

  We setup the project a while go, but we're finally getting started now. This blog post sets the ball rolling.

  First off, I'd like to zero in on a name for the Badge project so the Github repository can be created.

  Also, during the next week or two, it would be nice to flesh out the features, specifications and tools that we will use. Chime in.
  

• What Is This?

  Benchoff • 09/17/2014 at 21:16 • 0 comments

  A Hackaday Conference Badge?

  No, we're not having a con - at least not yet. We go to enough of those already. So many, in fact, that we thought it would be a good idea to have a Hackaday Conference Badge for all the conferences we go to. What is it? What will it do?

  • It's a badge tied to a hackaday.io account.
  • It's a badge with a radio module
  • It's a badge with a LED array/display
  • It's got buttons for UI
  • It beeps and flashes when it's close to another hackaday badge wearer. It beeps super loud when someone on the Hackaday crew is nearby.
  • It has an IR transceiver for sharing contact info.

  So far, it's pretty similar to other conference badges we've seen before. What makes this badge special? If you go to a con that Hackaday is attending/covering, you get one of those sweet virtual badges on you hackaday.io profile. If we're throwing a swinging party in room 812, Hackaday can send out a message to everyone in attendance.

  It's a physical extension of the hackaday.io community, made specifically for hacker gatherings of all types and sizes.

  Read more »

View all 6 project logs