Solution to Telit Modules Connectivity Issue on LattePanda 3 Delta

userHead LattePanda 2024-07-11 11:33:03 93 Views0 Replies

Hello LattePandaians,


We're excited to share a solution from community member Hendrik, who has found a fix for the connectivity issues with Telit modules.


Hendrik discovered that the Telit modules' SIM card detection does not comply with the M.2 specification. The UIM_PRESENT pin is set to active low by default, causing detection issues.


Here's the key information from the Telit FN990 hardware guide:

"Unlike the M.2 specification, the UIM_PRESENT pin is set to active low (Inserted) by default for the Telit unified function. So FN990 will detect the SIM card insertion when UIM_PRESENT input is changed from a logic 1 to a logic 0. If the user wants to change UIM_PRESENT pin to active high (inserted), please refer to AT#SIMINCFG of FN990 AT Commands Reference Guide."


To fix this, reverse the SIM detection logic using the AT command guide:

1. Open the AT command interface on your Telit module.
2. Find the AT#SIMINCFG command in the FN990 AT Commands Reference Guide.
3. Execute the AT#SIMINCFG command to switch the UIM_PRESENT pin to active high.
4. Save and reboot the module for changes to apply.


This should enable proper SIM detection in the LattePanda 3 Delta, allowing you to connect to cellular networks.

Thanks to Hendrik for his diligent work. If you have questions or need help, please reply to this post.




Welcome to join  LattePanda Discord community,  where you can dive into more topic discussions and share your insights!