• Friday, April 4, 2014

    #update #eric kolker #testing #voltage #power #tessel #technical machine #electrical engineering #test

  • Final Hardware Testing

    Thursday, April 3, 2014

    4/3/2014— Jon McKay

    Tessel version nine arrived at our office yesterday. It came in yesterday straight out of Worthington Assembly’s ovens.

    Each new hardware revision means a whole slew of tests to make sure we fixed any known problems and haven’t created any new ones.

    Eric is testing out how robust the board is after merciless shortings on both USB input and external power lines. He had designed new power circuitry to try and prevent the board from being fried in the event of a short and preliminary results are looking promising.

    I have a test rig to put our power switching circuitry through the hoops. Tessel can be powered off of USB or external power (up to 15V). We want users to be able to program Tessel over USB, then detatch out the USB cable and have their program continue running off of external power (if it’s connected) without a hiccup.

    Yes, the header on the old relay modules were assembled backwards and yes we are embarrassed. This relay module is plugged in upside down, and if you do that with the production models they won’t work.

    My test rig (above) has both USB and an external LiPo battery connected to Tessel at the same time. The USB power is intercepted by a debugging circuit board (below) that allows us to splice off USB power into a relay connected to Tessel.

    That allows Tessel to tell the relay to either connect the USB circuit or disconnect it. That is, Tessel is testing its own power regulation circuitry by switching its input power between USB and the LiPo. If the switch fails, Tessel will stop blinking lights because the program is stored in RAM and will be erased on power failure. Tessel testing itself is a beautiful thing.

    It both terrifies me and excites me that this revision of the board seems to be working to spec (knock on wood). If all goes well, we can be set to start up production early next week.

    Jon McKay

    #Update #Jon McKay #Electrical Engineering #Tessel #Technical Machine #Revision #Hardware #Testing #Test #Power #USB

  • Update: Shipping Schedule

    Tuesday, March 25, 2014

    3/25/2014— Updates

    Where we’re at on the reset issue:

    We got the pre-production boards back and have confirmed that the reset issue is fixed. But one of the parts used in the updated power plant did not perform to spec when placed on the Tessel (off-board tests worked fine, even when wired directly into the Tessel). The issue is only apparent when Tessel is powered over external power (not USB), but we don’t feel comfortable shipping something that is not working perfectly.

    We did another redesign of the power plant to fix the issue, and have sent out Tessel to the manufacturers for another test batch.

    What this means for scheduling:

    • Test batch: We’ve pushed out a new design to fix the power plant. We expect to get it back in about 1 to 1.5 weeks.
    • Manufacturing: Once we’ve determined that the new design works, we tell our manufacturers to go ahead. They start making them and then send us the batch in about a month.
    • Fulfillment: We send everything over to our fulfillment house, and they start packing up and sending off orders right away.
    • Shipping: Our fulfillment house will send you tracking numbers when they put your package in the mail. After that, domestic orders (USA) should receive Tessels in 2-7 business days; international orders should arrive within 2-3 weeks.

    Then you’ll have your Tessel!

    We’re working on making an excellent installation/first run experience, and we are currently setting up a forum, in addition to improving and finalizing firmware.

    Other news:

    We’ve added a link to the top of the status page that will take you to the latest updates-related post on our blog, so you can check there to make sure your information is current.

    Back to work!
    Kelsey, Jia, Jon, Eric, Kevin, and Tim

    #update #updates #tessel #technical machine #manufacturing #electrical engineering #reset #power

  • Tuesday, March 25, 2014

    #hardware #jia huang #tessel #technical machine #manufacturing #presentation

  • Monday, March 17, 2014

    #fluentconf #javascript #embedded devices #tim ryan #tessel #technical machine #presentation

July 2017

February 2017

November 2016

October 2016

September 2016

August 2016

July 2016

June 2016

April 2016

March 2016

February 2016

November 2015

September 2015

August 2015

July 2015

June 2015

May 2015

March 2015

February 2015

January 2015

December 2014

November 2014

October 2014

September 2014

August 2014

July 2014

June 2014

May 2014

April 2014

March 2014

February 2014

January 2014

December 2013

November 2013

October 2013

September 2013

August 2013

July 2013