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Forum Index : Microcontroller and PC projects : Armmite H7 5V Tolerance

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PhenixRising
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Joined: 07/11/2023
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Posted: 04:50pm 07 Feb 2024
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I get the impression from the manual that other-than the DAC outputs, the pins are 5V tolerant(?).
Yet reading the STM manual, it states that the pins are 3.3V. What am I missing?
 
matherp
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Posted: 05:13pm 07 Feb 2024
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All pins with analogue capabilities must be limited to 3.6V maximum. See the datasheet FT vs TT pins
 
Mixtel90

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Posted: 05:14pm 07 Feb 2024
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According to the RP2040 specification all pins on the Pico are 3V3, with an absolute maximum of 3V6. However, Raspberry Pi have said that the pins will *withstand* 5V. That doesn't mean they are suitable for 5V systems, as they can provide over 5V and remain in spec.

You pay your money and you take your choice. My own preference is to keep to the spec - 3V6 absolute maximum. At least on anything that I want to have running for any length of time. :)
Mick

Zilog Inside! nascom.info for Nascom & Gemini
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matherp
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Posted: 05:20pm 07 Feb 2024
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Mick - check the thread title  
 
Mixtel90

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Posted: 05:23pm 07 Feb 2024
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OOPS.....  :)
Mick

Zilog Inside! nascom.info for Nascom & Gemini
Preliminary MMBasic docs & my PCB designs
 
PhenixRising
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Posted: 05:40pm 07 Feb 2024
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For SPI, I should be OK with a 5V device then.

I have a WeAct and just wondering what F-CS is?
 
matherp
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Posted: 06:02pm 07 Feb 2024
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  Quote  
I have a WeAct and just wondering what F-CS is?


Chip select for a flash chip that may or may-not be fitted
 
PhenixRising
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Posted: 06:08pm 07 Feb 2024
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Dammit, I was trying to think of everything that begins with 'F' before asking  
 
disco4now

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Posted: 10:31pm 07 Feb 2024
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It looks like the gitHub site for the WeAct  H7 100 pin board is gone.
Here is the schematic for it I have previously downloaded.
STM32H7xx SchDoc V11-WeAct100.pdf

I have not looked to see if F-CS has a pullup, if not you will need to set it high  as the flash is sitting on SPI.
From the H7 manual for WeAct board.
  Quote  
The onboard W25Q16 SPI Flash chip is connected to SPI1 and its F_CS pin is 87 (PD6). It can be accessed
from Basic. Use SPI and set pin 87 as an output and use as the F_CS. See appendix E
Latest F4 Latest H7
 
PhenixRising
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Posted: 06:04am 08 Feb 2024
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  disco4now said  It looks like the gitHub site for the WeAct  H7 100 pin board is gone.
Here is the schematic for it I have previously downloaded.
STM32H7xx SchDoc V11-WeAct100.pdf

I have not looked to see if F-CS has a pullup, if not you will need to set it high  as the flash is sitting on SPI.
From the H7 manual for WeAct board.
  Quote  
The onboard W25Q16 SPI Flash chip is connected to SPI1 and its F_CS pin is 87 (PD6). It can be accessed
from Basic. Use SPI and set pin 87 as an output and use as the F_CS. See appendix E


Thanks Gerry, I wanna build my own board (doesn't matter which variety) so this could be useful.

Don't know if this belongs in the manual-corrections thread but you have illustrated above, why I had to ask about 'F-CS'. It is shown on the table with a hyphen but naturally, a search of the manual found no explanation because elsewhere it has an underscore 'F_CS'.

Loving this H7. Currently have 150mm dupont wires between the WeAct and a SPI device. Happily talking @ 20MHz  

Anything above that and I get bad data. Very impressive though.
SPI READ into an array (32bits) is also much faster than the 4-read method.  
 
Volhout
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Posted: 08:36am 08 Feb 2024
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PhenixRising,

I would never rely on 5V compatibility of IO pins if I was making a new design anyway.
There is minimum cost involved to add a level shifter. And there are plenty of them.
It makes it so much more robust.

Volhout
PicomiteVGA PETSCII ROBOTS
 
PhenixRising
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Posted: 09:54am 08 Feb 2024
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Hi Volhout,

The device will actually run on 3.3V so I'll probably switch to that.

What is not clear to me is that if the device is running on 3.3V, will the EncA, EncB and EncI inputs still be okay with 5V from the encoder.

counter-click-manual-v100.pdf
 
disco4now

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Posted: 10:28am 08 Feb 2024
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  Quote  Don't know if this belongs in the manual-corrections thread but you have illustrated above, why I had to ask about 'F-CS'. It is shown on the table with a hyphen but naturally, a search of the manual found no explanation because elsewhere it has an underscore 'F_CS'.

Now corrected in the source document so will be fixed in the next update.
Latest F4 Latest H7
 
Mixtel90

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Posted: 11:17am 08 Feb 2024
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I'm not familiar with the chip, but if it has a pin for the IO supply then you may find that inputs must not exceed the voltage on that pin - no matter what the specified maximum is. That's because any protection diodes will probably go to that pin rather than VCC.
Mick

Zilog Inside! nascom.info for Nascom & Gemini
Preliminary MMBasic docs & my PCB designs
 
PhenixRising
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Posted: 01:38pm 10 Feb 2024
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  disco4now said  
Now corrected in the source document so will be fixed in the next update.




Also, in a paragraph pertaining to the library topic, "existance" needs correcting.

Having lots of fun with this H7, Gerry. Getting all kinds of ideas.  

Not critical but I really like SYNC on the Picomite. Not possible with ARMmite H7?
 
PhenixRising
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Posted: 11:45am 11 Feb 2024
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"Adaptor" should be adapter.  
 
PhenixRising
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Posted: 02:08pm 11 Feb 2024
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5V Tolerant (FT)


en.STM32G0-System-General-purpose-IO-interface-GPIO.pdf
 
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