Tag Archives: hvrescue

Test Jig for the HV Rescue Shield

HV Rescue Shield Test Jig

This weekend I threw together a simple test jig for the HV Rescue Shield.

The completed jig is shown above.  There are four header pins, one at each corner, that are used to align the  BUT, or board under test.  The Kapton tape insulates the two bottom standoffs from shorting against the bottom of the BUT.

Pogo pins are used to make electrical connection to the BUT.  I connect to +5V, ground, 12V_EN, and 12V_SW (the +12V output).

These pogo pins are similar to the ones Ladyada uses in her test jig tutorial.  You can get these in a wide variety of styles on eBay. I think the ones I used are P75-K “chisel” type tips.  They just happen to fit into the existing holes in the PCB with no modification.

The height can be adjusted by melting the solder around the pogo pin and pushing it up and down.  I lost a couple pins when I pushed them down too far and let solder get into the spring mechanism.  Oops.

HV Rescue Shield Test Jig

The standoffs are made of reclaimed screws that I had lying around.  Right now I am connecting to the pogo pins with clip leads, but I might make a more permanent test setup someday.

HV Rescue Shield Test Jig

To test a board, I align it with the header pins and push down.  Easy.

Previously I was using something similar, but without alignment pins or standoffs, so it was challenging to align and push down the board-under-test with the pogo pins without the whole setup sliding around the bench.  The new jig works well and makes testing a large batch of boards a breeze.

BUT

Here’s my current testing setup.

Testing the HV Rescue Shield

The output of the 5 to 12V DC-DC converter is shown on the top display (that’s my beloved Fluke 45 bench meter) while the power supply current is shown on the bottom.  The toggle switch on the bench just to the right of the jig is so I can toggle the 12V_EN line and make sure the DC-DC converter turns off too.

This board looks good, and so did 29 of his friends.  0% failure rate on this build!  I seem to have my process pretty much figured out now.

Tested boards

HV Rescue Shield now works with the Arduino Mega

HV Rescue Shield works with Arduino Mega!

Thanks to John, of the ATX Hackerspace, who loaned me his Arduino for testing, the HV Rescue Shield now works with the Arduino Mega.

I had to create new byte read/write functions for digital lines 0-7 because they are implemented very “differently” (and I don’t mean that in a good way) in the hardware for the Mega.  If you’re interested in how I did this, check out the new version 2.12 Arduino sketch and the new mega_data_read and mega_data_write functions.

To use the HV Rescue Shield with the Arduino, first download the revised sketch here.  Set the MEGA #define to 1 and compile/upload the sketch to your board.  Make sure you have the Arduino Mega selected in the Arduino Board menu, or the sketch won’t compile.

The Mega has more pin headers than the Rescue Shield, so be sure to install the shield all the way to the left, as shown here:

HV Rescue Shield alignment on the Arduino Mega

If you experience any problems with the HV Rescue Shield and the Arduino Mega, please report them in the support forum.

HV Rescue Shield 2.1 Now Shipping

HV Rescue Shield 2.1

I have good news.  The latest and greatest version of the HV Rescue Shield is now available!

Version 2.1 contains a new and improved 12V switching circuit that resolves an issue reading/writing to parts with certain startup timer settings.  This issue affects all previous versions of the Rescue Shield kit.

I have kits in stock and ready to ship this week.  If you have been waiting for the new release, you can place an order now.

Note to HV Rescue Shield 2.0 customers: Because the startup timer issue was identified so quickly after version 2.0 was released, I am offering a free upgrade for all customers who purchased a version 2.0 kit.  Please contact me to arrange for a replacement.  This offer only applies to HV Rescue Shield 2.0 customers.

HV Rescue Shield Update #3

A quick update on the HV Rescue Shield:

About a week ago, I completed testing on a new switching circuit that allows me to leave the DC-DC converter on full-time and switch the RESET signal very quickly (risetimes in the microseconds).   Now there shouldn’t be any more  issues getting parts with zero SUT to enter HVSP/HVPP mode.

It’s taken a lot longer than I expected to get to this point, but the results look very good. I have had 100% success reading/writing all parts I have tested.

PCBs are on order and due to ship by the end of the week.  Assuming the layout is good and I didn’t just order a large batch of stylish (but small) coasters, I should have kits in stock again by the end of next week.

Watch here for updates, and my apologies to everyone who has been waiting on a kit – new and improved kits should be available soon.

Update 2/1: PCBs came in while I was away last week, and are currently being held at my local Fedex office, which is closed due to the power outages that are affecting Austin today.  Apparently Austin does not handle prolonged sub-freezing temperatures very well.   As soon as I can get my hands on the boards, it should only be a day or two before kits are available again.

HV Rescue Shield 2.0 status update

Just before the holidays, an issue with the Rescue Shield 2.0 (which I have at times referred to as “2.x”) was identified.  The issue involves problems reading/writing to parts that have certain startup timer (SUT) fuse values set.

There is some more information about the issue on the forums and in a previous post here and I created a Known Issues page on the wiki.

While this issue will not affect most users (this is why no one, including me, noticed it until now), I am currently working on a fix.  Initially I had hoped that I could fix the problem in software, but after spending far too much time pursuing that approach, I have decided to address it with a hardware change instead.  This should make for a much more robust solution.  I’m in the process of revising the hardware this week and hope to release a new version of the shield in the near future.

As soon as I heard about the issue in December, I stopped taking orders for Rescue Shield kits.  Kits and PCBs will show up as out of stock until I release the new version.

I’ll post another update when I have an estimate of when kits will be available again.

Thanks for your patience!