To clarify: I am working on an accessory for a Tormach mill running PathPilot (a flavour of LinuxCNC). It is for personal use so I don't need to especially worry about product cost but obviously I'd rather not spend a lot on something that may eventually be abandoned when I get a better idea. I could modify the Tormach source code to solve my timing problems but I'd prefer to use it unchanged to ease the installation of their updates.
Possible transmission speed increases with USB3 or even USB2 are irrelevant since the maximum data rate will be less than 100 bytes/sec. -----Original Message----- From: Chris Albertson <albertson.ch...@gmail.com> Sent: December 2, 2020 12:41 PM To: Enhanced Machine Controller (EMC) <emc-users@lists.sourceforge.net> Subject: Re: [Emc-users] USB - Serial question As said, you can simply have your device hold the ft232 reset pin low until it needs to be high but if you look at the Arduino UNO the way they did their USB/Serial interface design was to use an ATmega8U2 microcontroller. Older Arduinos used the ft232 chip, then they switched to the ATmega8U2 microcontroller because it offers better flexibility This chip has an on-chip a USB2.0 interface. The trouble with holding the reset pin low is that you then need a microcontroller to decide when to raise the pin. But if you do that, why not use a microcontroller that can directly drive USB and not have to install a ft232 chip. This is actually a really common design ad maybe most engineers go this route. There is no need for the ft232 if your microcontroller already has USB pins. One more thing, I don't know what you are building but if this is a new product you might want to look at newer USB standards. On Tue, Dec 1, 2020 at 6:23 PM <ken.stra...@gmail.com> wrote: > I'm looking for a USB <-> Serial chip (something similar to the FT232R > or > CH340) that has an enable pin so it can be plugged into the computer's > USB port but not initiate the connection process until the enable pin > is activated. One possibility is to power up the widget, wait and then > boot Linux but this is prone to operator error. Or perhaps someone can > suggest an alternate approach. > > To explain: > I am building an Arduino controlled widget that requires a lengthy > initialization delay to home the axis and other tasks before it is > ready to "talk" to Linux. I want to leave it plugged into the > computer's USB port but unfortunately Linux boots before it completes initialization. > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
