Greetings.
I've been playing with communication between RPi5 and ESP32 via UART and at some point RPi5 capability to transmit through Tx0(GPIO14) has ceased. Though if I send some data from ESP32 to Rx0(GPIO15) it is working. The least I can think why it stopped working - I was uploading code to ESP32 via USB while TX/RX were connected between RPi5 and ESP32. But I don't know if it could do any damage.
What I've tried so far:
- Checked voltage on GPIO14 with multimeter - it show 3.3-3.4V
- Switched GPIO14 to alt mode 5 and set it as Output, then hooked it to LED with resistor and switched LOW/HIGH. The LED is blinking.
- Tried to loopback GPIO14 and GPIO15 and send some input via minicom - I don't see characters that I type.
- Connected GPIO14/15/GND to corresponding Rx/Tx/GND on RPi3 and launched minicom on each. I see characters that I type on RPi3 instance. But if I type on instance of RPi5 there is no data in minicom.
- Enabled UART2 and connected GPIO4 and GPIO5 in loopback. Minicom on ttyAMA2 shows the input. Same if I hook GPIO4/5/GND of RPi5 to corresponding Rx/Tx/GND on RPi3 and open minicom on each. So it's not faulty wires or me messing up with connection.
Is there something I can do to check if I somehow fried TX capability of GPIO14?
I've been playing with communication between RPi5 and ESP32 via UART and at some point RPi5 capability to transmit through Tx0(GPIO14) has ceased. Though if I send some data from ESP32 to Rx0(GPIO15) it is working. The least I can think why it stopped working - I was uploading code to ESP32 via USB while TX/RX were connected between RPi5 and ESP32. But I don't know if it could do any damage.
What I've tried so far:
- Checked voltage on GPIO14 with multimeter - it show 3.3-3.4V
- Switched GPIO14 to alt mode 5 and set it as Output, then hooked it to LED with resistor and switched LOW/HIGH. The LED is blinking.
- Tried to loopback GPIO14 and GPIO15 and send some input via minicom - I don't see characters that I type.
- Connected GPIO14/15/GND to corresponding Rx/Tx/GND on RPi3 and launched minicom on each. I see characters that I type on RPi3 instance. But if I type on instance of RPi5 there is no data in minicom.
- Enabled UART2 and connected GPIO4 and GPIO5 in loopback. Minicom on ttyAMA2 shows the input. Same if I hook GPIO4/5/GND of RPi5 to corresponding Rx/Tx/GND on RPi3 and open minicom on each. So it's not faulty wires or me messing up with connection.
Is there something I can do to check if I somehow fried TX capability of GPIO14?
Statistics: Posted by Ravgni — Thu Jun 19, 2025 11:34 am