I have placed a version of firmware for the NanoVNA-H which supports the command line interface (shell) over UART on github (). This version of firmware can be used with the v3.4 version of NanoVNA-H which has pcb pads for the UART connection.
Source is on github in the UART_Shell branch. Key changes are in the board.h file (pin assignment) and main.c (start shell on UART serial).
Using this FW is fairly simple: to get the shell on the UART turn the nano on without USB connected, for command line access across USB turn it on with the USB connected.
I have done only minimal testing with a USB-to-serial converter but Piero, I0KPT has used it with an HC-05 Bluetooth module to successfully connect a laptop running NanoVNASaver to a nano.
I can only provide minimal support for this FW with no guarantee of turn around time but do please report issues through github.
The release info from github follows for your information.
Dave L., VE3LHO
Firmware with UART suppport for nanoVNA-H v3.4
This is a release of firmware for the NanoVNA-H which supports the shell (serial command interface) on UART1. Rx and Tx for this UART are brought to pcb pads on the nano in the -H v3.4 pcb and a header can easily be installed.
This FW starts the shell on the USB virtual serial port if the USB is active at power-on/reset.
It starts the shell on UART1 if USB is not active at power-on/reset.
If the USB is plugged in after startup you can revert to using the serial over USB link by "exit"ing the shell on the UART.
Serial port parameters used are the ChibiOS default which (as far as I can determine) are:
Data rate: 38400
Data bits: 8
Parity: None
Stop bits: 1
Flow control: none
This is based on a fork of Hugen's latest which I believe is the same as the Jan. 2020 release.
This FW has undergone minimal testing.
I have confirmed that the shell is started on the serial-over-USB when I start the nano with the USB cable plugged in, on my system (a modest 10 year old desktop running win10). Other systems may have different timing than mine and might exihibit different behaviour i.e. not (always) start the shell on the USB even if it is plugged in.
This FW has been used with an HC-05 Bluetooth module to implement a remote, wireless connection to a laptop running NanoVNASaver.
The settings for the HC-05 UART were:
AT+UART=38400, 0, 0
Other Bluetooth modules should also work but obviously will have different settings.
