Hi,
I am using ECSPI3 which is muxed with both UART1 and UART2. CS signal is coming on oscilloscope. But MOSI and SCLK signals are not coming.
Attached the mux dts code. Can any one verify whether dts code is right.
Thanks & Regards,
Kartheek
ecspi3_dts.txt (748 Bytes)
The UART1 pins are not brought out through the board to board connectors, they are connected to the wifi/bt chip on the SOM itself. It is not possible to use SPI3 with our SOM.
Hi @jnettlet
On our custom board we have isolated the Bluetooth. Using UART1_TXD, RXD for MOSI, SCLK respectively.
Will this work for the modified dts attached previously.
Thanks & Regards,
Kartheek
Can you please tell me the pins on the headers you are using for your carrier? This will help me cross reference them to the SOM.
Hi,
We have developed the custom the board with help of humming board 2.5version. Hence, we are not testing on humming board and SOM. Please refer the attached schematic and pin details for modification.
Modification done:-
In Cutomized board we have a requirement to connect TFT display on SPI, hence we removed/isolated bluetooth. Thereof, we used UART1_RXD as ECSPI3_SCLK & UART1_TXD as ECSPI3_MOSI.
We also moved the console from UART2 to UART4 & is working fine for us.
Issue Faced: We are able to see a toggle on the CS pin but unable to see any change on CLK & MOSI (It always remails LOW).
Attached table descries the changes, hope this will give you a picture of our development exercise and can expect a workaround for this.
| Sl no | Display Board | Interface pin name | Processor Interface pin name | Solid Run Cariier Board |
|---|---|---|---|---|
| 1 | SPI_MOSI | ECSPI3_MOSI | UART1_TXD_1V8 | BT_UART_RXD |
| 2 | SPI_SCLK | ECSPI3_SCLK | UART1_RXD_1V8 | BT_UART_TXD |
| 3 | SPI_CS | ECSPI3_SS0 | UART2_TXD_1V8 | UART2_TXD |
| 4 | SPI_MISO | ECSPI3_MISO | UART2_RXD_1V8 | UART2_RXD |
Thanks & Regards,
Kartheek
Just to clarify. You are directly using the UART1 pins on the SOM for the SPI connection? If so did you remove the BT device-tree node, and it’s pin definitions in your device-tree?
Hi @jnettlet,
Now ECSPI3 is working. We have connected wrong pins for MOSI, SCLK previously.
Now made the connections correctly.
Thanks for your valuable support.
Regards,
Kartheek
