General Question about Using Legato for Products


I am creating a product for a company that will use a few Sierra Wireless chips, particularly a cellular and a GPS chip. I will also need an accelerometer and a bluetooth module. I have a mangOH red board with a WP8548 as well as an HL cellular chip I can swap out. If I use the WP8548, I could have everything I need on this one mangOH board for prototyping and I could write my application using the Legato platform. Currently the plan is to use a separate MCU and then talk to the cellular chip via UART, as well as talk to a separate Sierra XA 1110 via UART ( by the way, if anyone knows how to talk to this XA1110 chip via I2C, please let me know. I cannot find ANY documentation on how to do this. For example, what is its I2C device address? And do I need a UART as well as I2C if all I want to do is grab location data?). Would be great if I could just use the mangOH red board for prototyping and write my application using the Legato platform…but my question is will the chip have to be recertified if I add my own application code to the WP8548??(meaning the cellular certification to make sure it doesn’t mess their networks up). Or is the cellular firmware locked down somehow?


The cellular firmware is locked down. You dont need to re-certify the module.
You are only adding an application in legato and/or building new drivers in the linux layer.


Thank you very much for your reply. I had a distributor of Sierra Wireless products tell me I would have to have it re certified. But it didn’t make sense to me. Luckily I just started this project and can maybe switch the direction I am going. Thanks again !!!


Note this is about the module. Now if you are doing a product, of course you need to get the whole product certified. Is that clear?


Yes. But in this case, it wouldn’t matter if I used the WP8548 to run my app, or used a separate MCU plus an HL7748. Correct ? There won’t be any extra certification from creating my app on the 8548 Legato platform. This is now how I understand it.


Yes, that’s correct.


Great. Thank you. Low power is a big requirement and it seems this platform can run a long time on a single charge. The fact I can use the mangOH board for my entire development is a plus too.