UART and I2C support with new LTE modem board

[bobwilmes 0 1 1]

Everything is OK so far with the Spresense hardware I received (thank you!). Got the bootloader flashed and nuttx loaded. I am looking to hookup my sensors (one I2C and one UART) and the layout of the board is significantly different from the one documented on the Spresense hardware web site (which shows a couple pull up resistors for the UART).

https://developer.sony.com/develop/spresense/developer-tools/hardware-documentation#_how_to_use_the_uart

Is there an updated hardware guide for the new board revision to show to hook up the UART and I2C sensors ?

![Spresense Hardware #1 (https://github.com/bobwilmes/airscape/blob/main/images/spresensehw1.jpg)

![Spresense Hardware #2 (https://github.com/bobwilmes/airscape/blob/main/images/spresensehw2.jpg)

!Spresense Hardware #3

![Spresense Hardware #4 (https://github.com/bobwilmes/airscape/blob/main/images/spresensehw4.jpg)

[CamilaSouza]

Hello, @bobwilmes-0-1-1
Yes, you were looking at an old version of the documentation.
This is the new one:
https://developer.sony.com/develop/spresense/docs/hw_docs_en.html
And now we have a specific hardware guide for the LTE extension board you are using:
https://developer.sony.com/develop/spresense/docs/hw_docs_lte_en.html

I can also refer a couple of examples that use the UART/I2C connection.
UART:
https://developer.sony.com/develop/spresense/docs/overview_tutorials_en.html#_how_to_connect_spresense_to_a_cellular_network
https://developer.sony.com/develop/spresense/docs/circuitpython_tutorials_en.html#_circuitpython_uart (This one uses the regular extension board, not the LTE one, but can maybe give good insights)

I2C:
https://developer.sony.com/develop/spresense/docs/sdk_tutorials_en.html#_hostif_tutorials
https://developer.sony.com/develop/spresense/docs/circuitpython_tutorials_en.html#_circuitpython_i2c (This one uses the regular extension board, not the LTE one, but can maybe give good insights)

I hope this is helpful