Is there problems interfacing the Propeller to arduino break-out boards with a TXB0108 translator?
Capt. Quirk
Posts: 872
It must be a common problem when manufactures build boards intended mainly for the 5v Arduino market,
with the breakout boards populated with 3.3v chips (devices). Are there common problems interfacing this
general type of board with a Propeller?
The Manufacture says the board operates on 5v or 3.3v.
My problem is output from the thermocouple board is zero. But I have confirmed the Propeller is inputting
the proper data. So I am wondering if the voltage translator is working. The Data sheet basically confirms my
suspicions, but I would like to know if this is a common problem?
From the TXB0108 data sheet:
My breakout board fits an Arduino Uno, and the Uno has a separate 3.3v power supply pin and at least two 5v
pins.
I am concerned that my 3.3v supply to a 5v power pin is causing the TXB0108 to disable the output ports, because
I have not supplied the other 3.3v pin. I think I need to power 5v pins with 3.3v and the 3.3v pin that supplies the
voltage translator.
The manufacture made this note in the Arduino software:
"3.3V (this is 3.3V output from on-board LDO (uno). DO NOT POWER THIS PIN!"
I am concerned that applying 3.3v to both pins may hurt something?
Thanks
Bill M.
with the breakout boards populated with 3.3v chips (devices). Are there common problems interfacing this
general type of board with a Propeller?
The Manufacture says the board operates on 5v or 3.3v.
My problem is output from the thermocouple board is zero. But I have confirmed the Propeller is inputting
the proper data. So I am wondering if the voltage translator is working. The Data sheet basically confirms my
suspicions, but I would like to know if this is a common problem?
From the TXB0108 data sheet:
10. Power Supply Recommendations
The TXB0108 has circuitry that disables all output ports when either VCC is switched off (VCCA/B = 0 V).
My breakout board fits an Arduino Uno, and the Uno has a separate 3.3v power supply pin and at least two 5v
pins.
I am concerned that my 3.3v supply to a 5v power pin is causing the TXB0108 to disable the output ports, because
I have not supplied the other 3.3v pin. I think I need to power 5v pins with 3.3v and the 3.3v pin that supplies the
voltage translator.
The manufacture made this note in the Arduino software:
"3.3V (this is 3.3V output from on-board LDO (uno). DO NOT POWER THIS PIN!"
I am concerned that applying 3.3v to both pins may hurt something?
Thanks
Bill M.
Comments
When there are two different power supply voltages, the higher voltage should go to the B side, but it sounds like you have 3.3 the on both sides for now. I've used the TXS010x series extensively. It is similar to TXB but designed for open drain applications such as the I2C interface.