bootloader

SeeCwriter · Joined: 18 Nov 2013 Posts: 162

Continuing the bootloader issue, even though I have it working with my PC, there are several other PCs in the company that are unable to load an application image.

All PCs are using Tera Term v4.89. I have used the same serial cables on all the PCs. I am loading the same application image. I've scoped the RS-232 signals from all the PCs and they are all the same. Yet several are unable to successfully load the image. Tera Term goes through the motions, and appears to end normally, but the PIC won't boot or run afterward.

Any ideas on what else I might looked for?

Ttelmah · Joined: 11 Mar 2010 Posts: 20061

Flow control settings.

Xon/Xoff flow control must be enabled for the bootloader upload to work.

SeeCwriter · Joined: 18 Nov 2013 Posts: 162

I didn't mention it, but the port settings were all the same between all the PCs. I went through every menu screen and verified the settings on each PC. And Xon/Xoff was enabled on all PCs.

temtronic · Posted: Mon Mar 07, 2016 8:16 pm

What OS ? What about supervisor/user access rights ? File protections ? Other applications ? Anything newer than W98 is full of 'overhead' that cn make you lose a lot of time and hair over !!!
I'd record EACH PC OS, setup, etc. to see what's common on the ones that fail to perform.

Jay

Jerson · Joined: 31 Jul 2009 Posts: 133 Location: Bombay, India

I would hazard a guess that the PCs which did not work are running on a USB-serial connection.

Ttelmah · Joined: 11 Mar 2010 Posts: 20061

SeeCwriter · Joined: 18 Nov 2013 Posts: 162

The serial ports used on the PCs were not USB ports with a serial adapter. They were standard RS-232 ports using 9-pin D-sub connectors on the motherboard of the PC.

Using a scope I can see the Xon/Xoff commands going back to the PC. But it's being suggested that Tera Term on some PCs doesn't enable Xon/Xoff but on others it does? That seems far fetched, but I will look into it.

All the PCs are Win7 Pro. It's interesting that someone mentioned supervisor/user access rights, because all the PCs that don't work are ones that our IT dept has seriously locked down. That's something that I considered briefly, but since other files can be sent successfully with those PCs I rejected the idea. Also, wouldn't I get an error message if the file could not be accessed or that Tera Term could not run?

Ttelmah · Joined: 11 Mar 2010 Posts: 20061

What happens is that TeraTerm itself, does not handle Xon/Xoff. What it does is signal the serial driver to enable this. It is possible to lock the serial driver, so it won't accept this command. However if Xon/Xoff is already enabled in the driver, then it will work.
Hence it is always safest to first enable it in the driver, and then in TeraTerm. If you can't enable it in the driver, then neither can TeraTerm....

SeeCwriter · Joined: 18 Nov 2013 Posts: 162

Wouldn't the same be true of the baud rate? I've verified I can change the baud rate in Tera Term.

Ttelmah · Joined: 11 Mar 2010 Posts: 20061

Funnily enough, no. Xon/Xoff, is specifically the one that gives problems. I think there is an internal difference in how this is 'exposed' by the driver interface. There also seem to be some drivers that just do not accept the command to enable it from a program, but have to have it set in the driver.

As a separate question though, 'are the versions of TeraTerm the same'?. There is a known issue on enabling Xon/Xoff in some versions.

Remember it is the PIC that is sending these, and it is then the driver/terminal program that has to respond to these. If data is being sent after Xoff is sent, before the next Xon, then 'you have your answer'. It's then a matter of finding how to fix it!...

SeeCwriter · Joined: 18 Nov 2013 Posts: 162

That's good information. I will investigate this further.

Yes, all the PCs have the same version of Tera Term, v4.89.

newguy · Joined: 24 Jun 2004 Posts: 1934

SeeCwriter · Joined: 18 Nov 2013 Posts: 162

temtronic · Posted: Tue Mar 08, 2016 3:28 pm

Every 'ENG PC' here is fully open and the 'TEST PCs' do NOT have Interent access (no need !).
Quickest way to get IT to 'open access' a PC, call then at 2:30 in the morning, telling them to get their butts down and ifx it cause the 'guy who signs their paycheck' wants it 'up and running' for the client at 9 AM.
BTDT it works...

Sad thing is there are NO standards anymore. One machine handles the USB ports on one 'chip' differently than then other 'chip' on the same motherboard! TRY to figure that one out...at 2:30 in the morning....

Jay