Tag Archives: AVR

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.

New Product: HV Rescue Shield 2.0

HV Rescue Shield 2.x

The HV Rescue Shield 2.0 is a high voltage parallel mode fuse programmer for Atmel AVR microcontrollers.

It currently supports a wide variety of AVR chips, including the 28-pin ATmega48/88/168/328 series, the 20-pin ATtiny2313, and many 8-pin ATtiny devices (such as the ATtiny25/45/85 and ATtiny13A).  A list of supported devices is in progress, but the Rescue Shield supports many more devices than those listed on the wiki.

The HV Rescue Shield 2.0 is in stock and ready to ship today!  Scroll down to place an order.

New in release 2.0:

  • Support for 8-pin ATtiny devices that use High Voltage Serial Programming (HVSP) mode!
  • Mode selection at startup so you don’t have to recompile the Arduino sketch to change parts.
  • More reliable HFUSE burning on all HVPP targets.
  • Numerous minor bug fixes and speed improvements to the code.
  • Reduced price, kit is now only $19.95 (was $24.95).   This means the kit is lower cost, but with more supported parts!


  • A working Arduino (tested with Arduino Uno, Duemilanove and Arduino NG)
  • A computer with USB and the Arduino IDE installed (tested with Arduino 0021)
  • A soldering iron and basic electronics assembly skills

What you get:

  • A high quality printed circuit board with the DC-DC converter preassembled, as shown below.
  • All other components needed to build the kit
  • An Arduino sketch, assembly instructions, Eagle schematics and layout files.

Here is a snapshot of the components included with the kit.


How to Order:

Visit the HV Rescue Shield 2.x product page to place an order.