Hey Everyone…
I know how difficult it is to find the correct drivers for hardware related movement on situated around 3.3v logic. Maybe make this thread something of use for posting about drivers:
- 3.3v only or around that logic…
- Wide range of current accepted…
- Not source but hardware…
Seth
P.S. I found some Toshiba drivers a while back that are dedicated to 3.3v logic but I have yet to find others that are of the same logic.
Ever since the mass “exodus” of hardware for electrical components during the pandemic, I have noticed some changes. Albeit, I still search from time to time for 3.3v logic drivers (hardware). This way, I can learn with the beagleboard.org boards, maybe make some posts, and then give back to the community if time permits.
Update
If anyone knows of such, fully made drivers that are already fully configured to handle motors, please jump in!
- TB6560AHQ,8 Toshiba Semiconductor and Storage | Integrated Circuits (ICs) | DigiKey
a. I found this driver a while back. On Mouser, it says minimum current is 2v while on Digikey, the reference is different on the main “purchasing page.”
- Anyway…I will try to keep updating the drivers here in case people are wondering about what is old-current-and-stable currently.
b. Of course, there are the L298 and L293 drivers. Those are good for basics and low cost pushing of motors in bipolar and/or both ways.
- I was reading about the basics from the datasheet for the 6560 from Toshiba.
c. It seems that there are many facets here. Some pins I/O need particular, extra circuitry (as usual). If I can get a Toshiba up and running, you will be the first to know.
More often than not, you can drive 5V TTL logic from a 3.3V micro.
With 5V TTL, anything above 2V is considered a logic 1. 3.3V logic should output a minimum of 2.4V for logic 1.
Now if you are connection very long wires you might get problems due to voltage drop, but most 3.3V micros I have seen drive logic 1 to around 3V.
Usually datasheets for chips will list a minimum voltage to be considered a logic 1
From the TB6560AHQ datasheet.
Obviously you can’t feed 5V logic into a 3.3V micro and expect it to be happy, although there are some devices that are 5V tolerant.
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Key points about TTL and CMOS logic levels:
TTL:
Logic low: 0V to 0.8V
Logic high: 2V to Vcc (typically 5V)
CMOS:
Logic low: 0V to around 1.5V
Logic high: 3.5V to Vcc (depending on power supply voltage)
I got that data from some AI stuff. I also was reading on the sites like Sparkfun to get a better grip on what is allowed and how…
For my DM332T drivers from a co. out there still producing them, I was unable to provide the correct circuitry to handle 3.3v HIGH while turning them off or floating with 0v to ~1.5v.
Of course for those drivers, there was a gotcha pin called OPTO that needed to have a steady current of at least 4.5v to supply logic to the driver.
Now, with this driver, the TB6560AHQ, I noticed many different ideas on the datasheet.
Even on the main pages online, I see Mouser state 2v while Digikey is saying 4.5v min.
With that hearsay, I was off to the datasheet thinking I got swindled into thinking this was maybe a cure for my woes of CMOS driver logic out-of-the-gate.
Seth
P.S. I will keep reading the datasheet. I see what you posted. That part of the datasheet must have gotten by me. Thank you. I have the datasheet for two separate, mostly identical drivers from Toshiba and was thinking it was as easy as they say. Plug and Play! Anyway, I appreciate your time Ben. Now, I can start to calm down and read more.
You really need to read the datasheets as the details on Digikey and Mouser can be misleading and not give the whole picture. For stuff like transistor and mosfets it is ok, but when you are talking about more complicated ICs not so much.
Quite often you can find chips that need 5V for the logic, but also have a separate power pin for the I/O interface allowing connection to lower voltage stuff.
I2C is great for interfacing to 5V parts as long as you make sure the I2C pull-up resistors are connected to 3.3V and not 5V
As for your DM332T driver all you need is a NPN transistor & base resistor for each control signal. The OPTO pin supplies the +V for the opto isolators and can be higher than 5V but then you need to add an external resistor to limit the current as the internal resistors on the module are for 5V input.
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You got it!
I have been reading the Datasheet(s) for a while now. I have been using the Gecko Drivers without error. This is nice for interfacing the beagleboard.org boards, i.e. as they have 3.3v to 0v min. while they also can be used 5v to 0v max.
Seth
P.S. I contacted the omc-stepperonline people to understand a bit more but received questioning from my questioning. And yes, you are right. The datasheets are where the data is located on the specifics. NPN transistor and resistor. Got it and A-Okay.