Uploading via the App.

When I try to send some code with the App, it looks like it does a reset() first, but on my board is seems to loose the connection completely. Is the App looking at signalling from the serial port RTS/CTS or some other USB signalling?

Yes, it does reset, but it's a software reset that shouldn't affect the USB. Sadly there is no RTS/CTS...

Is this with an Espruino board, or the discovery? I think you were using the discovery last time.

It could be that the discovery is losing some characters - I know USB on it isn't as reliable for some reason, but sadly nobody has made any attempt to fix it, and I have to focus on the Espruino board. You could try turning on throttling in the IDE.

It may be that you can actually recover it by doing Ctrl+C, echo(1), enter. Sometimes what happens is the board's buffer gets full, and it loses some characters which means that the last command (turning echo back on) doesn't get executed.

My final design will not have USB, so I was using the discovery with a console on a serial port via a FTDI cable. The com port does not reset, just the discovery, but the App seems to disconnect from the com port. I can send a reset from a terminal program and the connection remains. What is the App expecting back as response from the discovery? From a terminal I see 0x1b 0x5b 0x3f 0x37 0x6c 0x0d 0x0a and then the Espruino logo. I did add a datestamp under the logo, is it parsing the logo?

Did you try my Ctrl+C suggestion?

0x1b/etc are just escape codes to set up VT100 terminals correctly

The Web IDE sends some JavaScript code when it connects, and looks for a response. I imagine the problem might just be that there is absolutely no flow control on serial comms - XOn/XOff or otherwise - and if you send code that takes a lot of time to execute, that will cause subsequent code to get lost (once the buffer is full).

The Ctrl+C had no effect. I turned off 'reset() before send' and the code loads just fine, I have something useful now. It is strange I can type in reset() on the terminal side of the Web IDE and it does not disconnect, so I can work with this as a 2 step process for now. Thanks for the help and quick response.