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Zek_De
Senior
Apr 26, 2022 2:26 PM UTC
Solved

STM32L series with LORA Module(1.8V)

Hello everyone,

I want to make a project with STM32L series and LORA module and battery optimization is essential. I am going to run MCU under 1.8V but I am still not sure about LORA module. I am seeing support 1.8V operational mode. I assume if I have any problem 1.8V I will switch it to 3V3. In this scenerio, 1V8 stm32l0 and 3V3 Lora communicates with SPI and Lora spi will be 3V3. Can the stm32l0 handle the 3V3 spi com. Any person available here who is experienced about with 1V8.

Thanks in advance.

This topic has been closed for replies.
Andrew Neil
Andrew NeilBest answer
Super User
Apr 28, 2022 10:14 AM UTC

"I thought maybe I missed the important point on reference manuel like 1.8V has different working condition"

You need to look in the Datasheet (rather than Reference Manual) - that's where you will find electrical characteristics.

If the question's now answered, please mark the solution:

0693W000008y9fZQAQ.png

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.

5 replies

Andrew Neil
Super User
Apr 26, 2022 6:09 PM UTC

What LoRa module, exactly ?

You will have to check the LoRa module documentation to see if it is compatible with 1.8V.

Why not just use a level-shifter chip?

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
Zek_De
Zek_DeAuthor
Senior
Apr 27, 2022 8:05 AM UTC

Hi Andrew,

1 - I cant use level shifter by extra cost

2- I have read the docs and STM32L and lora support 1.8V. just this is my first experience in this voltage level and we are designing the board for 1.8V I hope it is ok. Also I checked it to ask someone yesterday(after posting this question again here)who has experience in lora module (hopeRF) told me it is ok. and also this circuit has lsm6dso, low power is important. As much as I see that is ok.

Andrew Neil
Super User
Apr 27, 2022 9:48 AM UTC

"I have read the docs and STM32L and lora support 1.8V"

So where's the problem?

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
Zek_De
Zek_DeAuthor
Senior
Apr 28, 2022 6:58 AM UTC

So no problem now, I post the question before I got the answers from someone, but maybe someone like me want to be sure reading this post. I thought maybe I missed the important point on reference manuel like 1.8V has different working condition. iks01a3 has level shifter and this made me doubt. That is it. Thanks for answers.

Andrew Neil
Andrew NeilBest answer
Super User
Apr 28, 2022 10:14 AM UTC

"I thought maybe I missed the important point on reference manuel like 1.8V has different working condition"

You need to look in the Datasheet (rather than Reference Manual) - that's where you will find electrical characteristics.

If the question's now answered, please mark the solution:

0693W000008y9fZQAQ.png

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.