Unfortunately, our isolation requirements are pretty severe. The AVR and associated components are run off of an unisolated AC line supply (a storage cap, limit resistor, zener supply; there was some discussion about this via the FSAR001 chip on the front page and in the general forum).
Our problem is keeping the line voltage away from the RS485 interface. Since rs485/rs422 is more of an industrial application, the chips tend to be expensive. Your application looks a lot like MIDI where the isolation (mandatory by the spec) is used to avoid ground loops. The DMX512 stuff (a stage lighting standard) is close but we never found anything better than the ADM2481 and we were quite disappointed when the final price was a lot more that the projected cost they released before production began.
What isolated RS422 receiver are you using? We're building something with isolated RS485 interfaces and they end up costing more than the AVR microcontroller. We've only found the (very new) ADM2481 and the NVE IL3185. There are some Maxim chips but they are even more expensive.
Shipping for digikey is only $2.41 for USPS, too bad that mouser is so high. Mouser has thermal cutoffs, but they only go up to 150 degC. Digikey has some thermal switches that might work, and in a much more reasonable temp range, but they are not an exact fit like the mouser part.
The two exact fit temp switches are either 105-115 degC (stock) or the 157-169 degC switch that the modding article suggests. That's quite a bit higher. I'd suggest firing it up outside first.
I cracked open a GBC Creative Laminator Model 9, #1701861 that I got off of ebay for around $20. It's a USA model. I found one thermal fuse and ONE thermal switch, unlike the modding instructions for the US models found on the ultrakeet site which show TWO thermal switches. This is the beige top model, not the blue one. I haven't tried the PulsarProFX system yet due to printer issues.
If anyone actually wants to make a more useful version of thses vertical SMT adapters I've got a few ideas after using a lot of different sioc, ssop and tqfp adapters from different vendors.
These things need to be as generic as possible. I've got drawers full of them, all different. Most of them just have the basic device footprint routed to the pins on the edge of the board. That's easy to layout, but most devices are on a standard pitch, so some thought can produce a generic footprint that a range of devices will fit. My favorite version of this is the "digole 337" (ebay seller "dig-ole"), pictured below. It's for 0.8mm tqfp from 32 to 48 pins. The footprint is pretty tricky, and asymetric but it actually works. They make another one for 0.65mm pitch tqfp 44 to 80 pin (and 0.5mm on the back side). It looks similar but has double row pins at the board edges.
The flaw with these things is that they don't fit a solderless breadboard. I stick them to thru-hole grid breadboards (second picture shows a digole 337 socketed to a Sure Electronics MCU board). You can also use IDC connectors or cut breadboard jumper wires and attach 0.1 molex connectors (16-02-0103) and jumper pin headers to a breadboard. Basically it's either very ugly or very committed.
That's where the vertical, microinventor style board comes in. His board only works for a single footprint; it needs to be made generic via the digole footprint. Similar boards could be made for soics which are all the same pitch and just differ in width and pincount, same for ssops (with a few exceptions).
The other issue with these boards, especially when used with microcontrollers and fpgas is that they all want a few things as close as possible to the chip. Power supply decoupling caps, crystal+caps, fpgas want oscillators, and anything with lots of pins wants a jtag or ISP connector. It would be nice to have room for that, but not connected to the footprint so it remains generic.
Some guy (microinventor) on ebay sells a few vertical tqfp adaptor boards. He does 44, 64 and 80 tqfp and they span .3" on a breadboard. The trick is that there are two lengths of right angle pin headers and you solder it while plugged into a breaboard. Attached is a picture of one in use.
>When testing, just be sure that your target JTAG is 3v3 compatible
Can you use other target voltages If you turn pullup resistors on, and supply Vextern with the JTAG interface voltage? This is a real issue for FPGAs and CPLDs.
