On Fri, Jun 12, 2020 at 6:22 PM Gregory Nutt <spudan...@gmail.com> wrote: > > Hi, Brennan, > > I am inclined to stick with the FT245RL because the boards are cheap and > readily available. Conceptually, the basic solution does not depend on > the selection of hardware. The hardware does effect performance and > scalability, but I think the that the hardware selection is not critical > for initial development. > > I can get the RT245RL board for ~$11 USD on eBay an adequate > STM32F103/F407 for $10-15 from China. Ready availability, inexpensive > hardware (albeit low performance) would probably be a better starting > point.. unless you can point to a competing low cost OTS solution. The > combined cost is around $20 and meets all of the initial development > requirements. I would have to have to have strong reason to deviate > from that. But I could be very easily dissuaded with an alternative OTS > hardware proposal at similar cost. > > Nothing I have said precludes that alternative, higher performance > implementation. At a block diagram level, it does not matter. It is > just a matter of drivers on both sides. > > Greg
Makes total sense if it provides enough bandwidth. There are some other options that are based off of the FX2 USB2.0 chip that are common in low cost ($10) 8ch 25MHZ logic analyzers as well. As you said it's a block with a few input pins, FIFO, and a usb interface, so if it works, sounds good. I am wondering if the host side could be implemented by leveraging sigrok and pulseview? https://sigrok.org/wiki/Protocol_decoder_HOWTO One of the advantages would be the ability to easily overlay other datasource as you already have some major chunks built? Had you put much thought into what the target side would look like from an interface? Not trying to dissuade from building something new :) Here is an example using sigrok+pulseview and a $15 logic analyzer https://learn.sparkfun.com/tutorials/using-the-usb-logic-analyzer-with-sigrok-pulseview/all --Brennan
