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temtronic
Joined: 01 Jul 2010 Posts: 9081 Location: Greensville,Ontario
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Posted: Fri Feb 05, 2021 6:27 am |
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The ST2378 does have +5 on port B, the user I/O side, PortA is connected to the PIC, and 3 volts.
What's kinda scary is that 'power in' (9 volt barrel plug) IS connected to the 10 pin 'DIO ' connector pins 1(gnd) and 2( +9).
Sure hope the ST2378 can take the occasional +9 on portb !
OUCH ! downloaded the datasheet, says +7 MAX so...I can see the ST2378 producing 'magic black smoke' if you miswire the 10 pin IDC connector...
There are no pullups on the DIO pins..
Jay |
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Ttelmah
Joined: 11 Mar 2010 Posts: 19195
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Posted: Fri Feb 05, 2021 8:13 am |
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Where is the OE connected to?.
The ST2378, won't give an output till this is enabled. Has to be taken high to
enable the chip. |
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temtronic
Joined: 01 Jul 2010 Posts: 9081 Location: Greensville,Ontario
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Posted: Fri Feb 05, 2021 8:15 am |
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OE is tied to VB and +5V |
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Ttelmah
Joined: 11 Mar 2010 Posts: 19195
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Posted: Fri Feb 05, 2021 8:23 am |
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OK. So it is permanently enabled then. OE is 5V tolerant. |
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