TTL ISOLATOR
For a better electrical protection of any UART TTL devices plugged into the PVbrain2, a mini-isolation card has been created.
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It can be placed to any of the 8 below UART locations, numeroted UART0 up to UART7 on the board (need to be plugged into the external pin's columns as the isolated RS232 module, it shares the same footprint).
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Two choices are possible for the power supply of the second part of the isolation chip.
Important
it will be necessarily to place at least one jumper onto the card otherwise nothing will work
The sensor does not have voltage 5V or 3V3 (eg. JKBMS)
It can therefore be connected thanks to a JST XH 2.5 plug at the bottom of the card (correspondly to the chosen UART).
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All you need to do is to wire:
PVBRAIN
┌──── INTERNAL ────┐ TTL-TTL
┌──────────┐ ┌──────────┐ ┌────────────┐
│ │<TX-------RX>│ │<TX-------TX>| |
│ PVBRAIN │<RX-------TX>│ TTL │<RX-------RX>| DEVICE |
│ │<----GND---->│ ISOLATOR │<----GND---->| |
│ │ 3V3---->│ |<----5V | |
└──────────┘ └──────────┘ └────────────┘
- The
TX<-->RXcrossover is done directly in practice via the PVBRAIN2 board.
And placed a jumper as depicted below:
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The sensor has voltage (5V or 3V3) (eg. SMARTSHUNT VICTRON)
It must therefore be connected to the JST PH 2.0mm terminal blocks on this insulator.
All you have to do is connect the 5V or 3V3.
- To the 5V pin then
TX-->TX,RX-->RXandGND-->GND. - The
TX<-->RXcrossover is done on the PVBRAIN board.
And placed a jumper like in the image below:
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For sensors that need a power supply (eg. Pzem004t V3)
You will need a double jumper or shunt the 3 pins as below:
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It must therefore be connected to the JST PH 2.0mm terminal blocks on this insulator.
All you need to do is connect 5V-->3v3 of sensor TX-->TX, RX-->RX and GND-->GND.
- The
TX<-->RXcrossover is done on the PVBRAIN board.
Note
The DC/DC isolation module outputs only 3V3/1A to power the sensor connected with
