Someone already wrote a program and made a simple instruction for building the hardware that lets you read every type except for the "Avid Encrypted" tags, which can be read but not decrypted. They also put a web API online for decrypting the Avid Encrypted tags and they have instructions for how to build your own decryptor (they call it a "translator"), however building the decryptor requires a ~$300 piece of hardware. Everything is here.
Standards and "Standards"
All chips operate at either 125 kHz (ISO) or 134.2 kHz (proprietary) but a scanner using either frequency can read both types:
Although ISO chips are optimized for 134.2 kHz, in practice they are readable at 125 kHz and the "125 kHz" chips are readable at 134.2 kHz.
-- from this section on wikipedia
ISO 11784 & 11785
Includes half-duplex (HDX) and full-duplex (FDX) types. I've seen references to FDX-A and FDX-B but unsure of the difference.
- juul ordered a bunch of FDX-B chips
- HDX are available on aliexpress for ~$20 for 10x but haven't been ordered since they are generally not used in pets
Readers retail for ~$150 on ebay.
- juul ordered and received a Hitag S256 chips.
- juul ordered 10x FDX-B chips from ebay
- juul ordered 10x FDX-A aliexpress... maybe. They are listed as both ISO FDX-A and Fecava at the same time. According to Max these types are actually using the ISO FDX-A standard but with every bit in the protocol inverted. The ones ordered are more likely ISO FDX-A than true Fecava.
Also known as Trovan Unique. Also used by some HomeAgain chips and Bayer chips.
We have not been able to source these.
FECAVA / Destron
- Avid EuroChip
- Original HomeAgain chip
- juul ordered 10x of these from aliexpress... maybe. They are listed as both ISO FDX-A and Fecava at the same time. According to Max these types are actually using the ISO FDX-A standard but with every bit in the protocol inverted. The ones ordered are more likely ISO FDX-A than true Fecava.
Also known as Avid Encrypted.
- juul ordered a single on of these from ebay. It cost $33 which is why he only ordered one.