HV Rescue Shield 2.0 status update

January 12, 2011 Jeff 2 Comments

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!

Books and Resources, Electronics

Ali’s Surplus Stuff

January 10, 2011 Jeff 10 Comments

Over the holidays I had a chance to visit Ali’s Surplus Stuff in Sacramento, CA.

Ali's Surplus Stuff

This is my kind of place. Surplus electronics piled from floor to ceiling. Lots of oscilloscopes and useful stuff mixed in with bizarre industrial equipment.

Ali's Surplus Stuff

Lots of cool rack-mounted equipment here. Lots of push-buttons too.

Ali's Surplus Stuff

Need a random computer-related printed circuit board?

Ali's Surplus Stuff

My recommendation for places like this is always to come to the counter with the biggest pile of stuff you can carry and haggle on a single price for everything. You’ll end up paying a fair price for one or two big items and getting the rest thrown in “for free”.

Ali's Surplus Stuff

Here’s what I went home with: HP chart recorder, some IC sockets, webcam stand, random RF module, and some kind of monitor shutoff device from back when ‘green’ was just a color. This is a remarkably small pile of stuff given what was available, but I knew I would have to pack all this into my checked luggage on the flight home.

Surplus finds

This was my first visit to Ali’s, and I came home really impressed. I can’t think of a better place to find surplus electronics junk in the Sacramento area, especially now that HSC Electronics on Auburn Blvd. is gone. I also feel that if you are looking for used industrial and test equipment, Ali’s has a better selection than Bay Area shops like Weird Stuff. I will definitely be visiting Ali’s again the next time I’m Sacramento.

Ali’s Surplus Stuff is listed under Sacramento Area on the resources:surplus page of the MightyOhm Wiki. Whew!

Microcontrollers

Issue with Rescue Shield and targets with SUT = 0ms

December 21, 2010 Jeff 1 Comment

HV Rescue Shield 2.0 customer Matthew Beckler has uncovered an issue that affects all variants of the Rescue Shield.

Long story short, if the target AVR is configured for a fast internal clock and zero startup time (eg. LFUSE=0x62 on the ATtiny13A gives a 9.6MHz clock with 14CK +0ms startup delay), then a slow rising edge on the 12V RESET signal from the Shield results in the target not entering or dropping out of HVSP or HVPP mode. The symptom is that regardless of the fuses stored on the target, the Rescue Shield fuse reads return 0xFF. In addition, the fuses can’t be changed.

I am currently investigating a solution. There is more information about the issue and updates regarding debugging in the HV Rescue Shield support forum.

Kits

HV Rescue Shield 2 and ICSPOV Shipping Update

December 15, 2010 Jeff Leave a comment

HV Rescue Shield 2 ICSPOV

This week I’ve been busily shipping orders for the HV Rescue Shield 2 and the ICSPOV. Some folks have been buying one of each kit and building their own mightyohm sampler pack. Cool!

A couple notes about shipping:

While the shipping notes on the product pages say to allow 1-2 weeks, this is really the worst-case scenario (parts shortages, I’m on travel, etc.). Typically I ship within 3 business days max, and often I ship the next business day if possible. Domestic customers, you will typically receive your order within 5-6 business days. International shipping takes quite a bit longer because of the shipping time and customs delays.
I will not be shipping orders between Dec. 23rd and Dec. 30th, so if you place an order during this time, you’ll get it sometime after Jan 1st. If you want kits sooner, order before 12PM CST on Dec 22nd.

Lastly, I want to thank everyone who has placed orders this week. Thank you!

Happy Holidays everyone.

– Jeff

Electronics