I can probably build firmware to this for you and assemble a list of OTS parts you can connect together in a day or two - what string do you want to trigger on? Parameters, 8N1? RTS/CTS? Voltage at RS-232 or TTL level?
OTS parts cost maybe $30? Source: am firmware engineer at Peloton (and still employed, wheee). -- Anders Nelson On Sat, Nov 12, 2022 at 12:27 PM Peter Corlett via cctalk < cctalk@classiccmp.org> wrote: > On Sat, Nov 12, 2022 at 10:28:09AM +0000, Tony Duell via cctalk wrote: > [...] > > The other day I saw a product with a flashing LED, the flash rate was set > > with a knob. Yes, a microcontroller with a pot connected to an analogue > > input and LED hung off an output port. This is the sort of thing I'd do > > with a couple of transistors or an NE555 depending on which turned up in > > the junk box first. > > Farnell Nederland is quoting me €1.06 (+21% VAT) for the cheapest brand of > 555 in stock. Their search won't let me find the cheapest microcontroller > without drilling down further, but an 8 pin AVR is €0.88. That's single > item > quantities in DIP packaging, as is typical for small home projects. The 555 > will also need a capacitor for its RC timer circuit which is another few > tens of cents. And that's why people use microcontrollers to blink LEDs. > > The MCU in the Pi Pico is also well under a euro if you buy a reel of 3,400 > of them. That's probably a few too many for an average hobbyist :) > >
