SX126x device ID

Hello everyone,

Recently, I’ve been playing a bit with the SX126x transceivers. By dumping all of the registers, I found some useful and seemingly undocumented information. For example, at the address 0x0320 - 0x032F, there seems to be some device ID and possibly a revision string:

0000320 53 58 31 32 36 31 20 56 32 44 20 32 44 30 32 00 | SX1261 V2D 2D02.

Is it correct to assume that this is indeed the device type (“SX1261”) followed by some revision (“V2D 2D02”)? And if so, is this format documented somewhere?

More generally, would it be possible to publish some register map, as it was done on SX127x? I understand that some (or most) of the register contain some testing functionality which may not be published. However, the example above is something I was missing quite a lot on the SX126x, whereas on SX127x, this was as easy as reading a device ID register. I imagine there could also be more useful stuff in the registers.



I was made aware of the following topic: Detect transceiver version

The answer there was it is not possible. @tomasz.kasprzak @mantoine it seems like it is possible after all, no?

After a bit of digging, I found several SX1262 devices that contain the string “SX1261” as the device ID - even though the package marking is clearly “SX1262” - so detecting SX1261 vs SX1262 might be a bit more tricky. SX1268 devices seem to have the correct “SX1268” string.

It would be customer-friendly to get a reply from Semtech on this question.

1 Like

I wasn’t able to distinguish them. I tried writing settings for SX1261 to SX1262 (and vice versa) hoping that maybe something will be rejected, but unfortunately no luck there. After all it looks like core chip is exact the same (as you found same string ID) and only it’s “peripherals” differ. That’s why most differences are in power amplifier and power circuits. Looks like it’s something like SiP but made in silicon.

Best Regards

This is not a public information so far (these registers are not described in the datasheet). We are working on an official answer to this topic.

1 Like

As stated in Detect transceiver version, it is not possible to discriminate a SX1261 from a SX1262 - even with the undocumented register you found. As explained by @tomasz.kasprzak, this register is only useful to know if this is a SX1268 or not.

We are working internally to find how we could clarify that in a next version of the datasheet (see SX126x device ID).

the SX126x datasheet shows the below OCP overcurrent protection register with different default values for SX1261 and SX1262. Would that be an appropriate way to distinguish between the two chips?