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What’s On the Bench

Sometimes it’s nice to just enhance an existing product, especially when the supply of blank boards starts running low and more need to be ordered.  I’m running low on the SD shields so it was a good time to make some improvements.  This is a prototype:

The changes from the Rev 4 boards:

  • A DS3231 RTC and backup battery are now on-board instead of having the plug-in RTC.  Too many of those plug-in boards had batteries that died within a year or two, so I decided to just put the chip directly on the board and have a battery connector.  It takes a very common LR44 battery which can be replaced easily when it fails.
  • DIP switches are clearly labeled as to which is which, and which direction is on and off.
  • A pull-down resistor is temporarily added here to fix a problem where the green and red LEDs don’t work right until the host computer initializes the interface to the SD shield.  A pin was left floating and confused the software into thinking the host was sending a byte when it wasn’t.
  • Two I2C pull-up resistors were added but do not seem to be necessary.

There will eventually be a Rev 6 with the new pull-down resistor and maybe the two pull-ups removed, but I’ll use the current Rev 5 boards and manually add the pull-down for now.

The RTC is completely software compatible with the current boards so any version of our Arduino code will work with it.


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New Store Category: Chips

Some customers of our bare boards have a hard time trying to find some of the vintage components, so I started adding them to the store.  Initially it’s just MC14411 baud rate generator, MC6875 clock generation chip and6532 RIOTs.  I’ll add some more parts, but I’m really not in the parts business, these are just for people needing a few odd chips for building one of our bare boards.


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It’s Been Quiet Here

It’s been a while since I posted anything and people are emailing asking what’s up, so this is an update.  My day job is still really good but taking a lot of time, so there are evenings when Corsham Tech just doesn’t get the attention that it used to.  We’re still here, just not spending quite as much time as in the past.

A few months ago I talked about a shortage of parts, and we’re happy to announce most of the parts backlog has been filled, except for the dreaded Molex connectors used on every SS-50/SS-30 board.  A large order was supposed to ship the end of February but the vendor informed me that the manufacturer (Molex) won’t ship until late May.  That’s too long, so I looked at more expensive  sources and found big companies like Digikey also have zero in stock.  A bit more searching and I found a bunch and ordered a few hundred.  My expenditures on Molex parts is in the order of $700 for the year so far.

The number of products on the web page is a lot more than I had ever planned, and a few of the low-selling items will disappear.  However there will be some additions like those hard to find parts needed for some of the boards I sell, such as the MC14411, MC6875, 74HCT145, etc.  There will also be packages of those parts so someone can buy some of the least common parts along with blank boards.

I’m starting to spend more time with some of my other hobbies again.  Over the last few years I’ve made maybe 100 contacts on my ham radio, compared the few thousand a year in years past (ie, contesting).  I keep hearing more about the JT8 protocol and have finally gotten it going, hoping to spend more time on it this weekend.

Another old hobby is robotics, mostly spurred on by my son in college (Drexel) where he’s taking a cool robotics course this quarter.  The last time he was home he got my wife and I diving into our old robot stuff again, me doing some work on home-built bots, while my wife got back into the Lego system.  She uses them for STEM demonstrations for Girl Scouts, but is doing more with them now.

There is one new revision to an existing board coming.  I have the prototypes and just have to site down and do more surface mount soldering and then see how it works.  Nothing major, just fixing a problem I didn’t like in an existing board.