I am implementing a serial transmitter using the nrf_serial library from the nRF5 SDK 15.3.0. The application is very similar to a serially addressable LED string.
My serial instance is initialized as follows:
I'm running into issues with the UART inserting extra data into my serial data stream. I am trying to send the data 0x00, 0x44, 0x77, 0x01. When I turn on debugging for the UART module, I see the following in the debug terminal:
<info> UART: Transfer tx_len: 4.
<debug> UART: Tx data:
<debug> UART: 00 44 77 01 |.Dw.
<info> UART: Function: nrfx_uart_tx, error code: NRF_SUCCESS.
This indicates to me that the UART driver is getting the correct data passed to it. However, when I view the output on my oscilloscope, I see extra data being inserted, such that the waveform that ultimately comes out reads 00 44 67 76 01 (see image)
Has anyone seen something similar to this in the past? Any idea what might be going on? All help is appreciated.
Thanks,
Kevin