I wonder why would anyone who actually knows what they're doing in embedded bother with Arduino in the first place ?
One of the reasons that I “bother with” Arduino is that code I write is more likely to be useful to “other people.” A sort of “customer oriented” philosophy, I guess. I tend to be interested in writing “deep infrastructure” code, so it’s frequently hard to feel like I’m doing anything “useful”, but if I, say, fix the Adafruit SamD51 arduino core implementation of “delayMicrosecondsuple()”, the I’ve potentially helped a lot of people...
Back to HPIB: feel free to do usb-serial-HPIB if usb is too scary. The “working example” that I found first used an uno, which doesn’t have native usb support, either.
It seems to me that the big stumbling block is likely to be the sink current needed to ensure a logic 0 output from the micro is recognized. A couple of 74F gates with some 2.2k pull-up resistors is going to stress some of those modern 4mA uC outputs (no, I didn’t check the stm32 specs - they are generally better than 4ma, right?)
And yeah, something that doesn’t meet the specs will always require testing in the exact use circumstances that you’ll use. Especially given the long lifetime of GPIB. But one working example is a start...
Hey if fixing Arduino code is your thing, I apologize for my use of the term "bother with”, no insult was intended, especially not to you.
What percentage of Arduino users would even know the different delay() mechanisms possible with that MCU I wonder ?
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I agree, there are no doubt plenty of specs to be considered to do the job properly, and I sure didn't claim (and wouldn't) that a STM32F could drive the GPIB bus directly.
For one thing, I've no idea of the specs of the GPIB bus, and I'm not likely to care because I've never needed it, it's old, and we have Ethernet now instead.
What does interest me however is learning the 'typical' parameters of a STM32 talking to some TTL and writing up my findings. I'll do this in the next couple of weeks as soon as I can find the time AND some TTL as I ditched my stock of brand new Ti TTL chips a few years ago.
I lived and worked thru the "Age of TTL" and I was incredibly relieved to see it's demise. Thank you oh God of CMOS!
It is important to note that STM32 GPIOs configured as inputs are 5-V tolerant, not 5-V compliant meaning that 5 V is tolerated by internally clamping the input voltage to VDD.
As far as OUTPUTS are concerned there are a TON of factors, voltage levels, rise and fall times, noise etc. This is proper design territory.
Sure, the STM32 may be far from 'TTL compliant' but what makes everyone think that Arduino MEGA328P is any better ?