Why does pin 5 has 1,5 volts when unexported or exported as input?
I have this kind of amplifier circuits connected to pin 5 (Linux GPIO 3) and pin 7 (Linux GPIO 4) on my Up Board.
The circuit in pin 7 works as expected. It acts like a floating input during boot and I can set the output state at boot time using the jumper.
Pin 5 however stays at 1,5 volts during boot and it pulls the voltage at the transistor base to 0,7 volts regardless of the jumper setting. Voltage stays at 1,5 volts even after the pin is exported. When I configure it as output I can write it high or low and the voltages are 0 volts and 3,3 volts as expected. I have already tried to disable everything I2C related from BIOS. How can I make this pin act as a floating input?
- 261 All Categories
- 103 Announcements & News
- 33 Product News - New Product/Product Change Notice/ End-of-life
- 174 Welcome Developers!
- 47 Unboxing & Project Sharing
- 14 Tech Updates
- 179 UP Products
- 16 UP Squared Pro
- 100 UP Xtreme
- 744 UP Squared
- 1.3K UP Board
- 79 UP Core Plus
- 205 UP Core
- UP Xtreme Lite
- 34 UP AI Edge
- 207 Starter Kits & Peripheral