Nv table in imp005

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1

Hi All,

I need to upgrade a project to imp002 to imp005 and I’m a new user of electricimp technology. The imp002 code project developed relies on nv table to many things, and I noticed that imp005 and impOS36 have no nv table support.

what can I do to have a non-volatile storage such as nv table in imp005?

Regards,
Rodrigo

2

impOS (all versions) have nv support when they are on devices that have backup SRAM and support deep sleep.

imp005 does not support deep sleep at all - the silicon isn’t capable of this - and so nv doesn’t exist.

imp004m/imp006 do support deep sleep, but the silicon doesn’t have any backup SRAM, so there’s no nv. However, imp004m/imp006 also have a very low current “shallow sleep” which preserves all RAM - in fact, it just appears like your squirrel code is always running, even when the system is consuming a few tens of microamps.

In almost all cases, customers who used deep sleep on 001/002/003 projects and then moved to 004/006 just use shallow sleep.

3

…if you want to store data across power cycles on any imp, there are options:

  • small amounts of data, with system-provided protection for the data: use https://developer.electricimp.com/api/imp/setuserconfiguration and getuserconfiguration. This storage is space-limited, but wear-leveled and (in the case of 005, where it’s off-chip) encrypted and protected with AES-GCM-AEAD and a device-unique key. Number of write cycles will depend on the size of the data and how often you change it.

  • large amounts of data, use the hardware.spiflash area and (eg) the SPI flash filing system library. This is not encrypted on any imp, but you can hash it with a key stored privately (eg in your code or in the user config place) and https://developer.electricimp.com/api/crypto/hmacsha256 - this will prevent anyone modifying it without you noticing.

4

Hi Hugo!

tks for your answer! I spent yesterday investigating the imp006 and seems it is sampling and not massive production (and I did not find breakout kit to buy).

Do you know where I can find the imp product lifecycle?

Regards

5

It’s available, just not promoted yet… there will be an announcement soon :slight_smile:

If you contact sales@electricimp.com, the breakout is available and parts are available too.

All imps that have ever been made are fully supported, back to the imp001 in 2012. imp003/004m/005/006/impC001 are all available.