ESP32_S3_OCTAL: OneWireHost.FindAllDevices() always returns 0

[Joe9899]

Environment

• Target: ESP32_S3_OCTAL
• Firmware: 1.17.0.115
• Hardware: ESP32-S3-N16R8 (16MB Flash, 8MB Octal PSRAM)
• NuGet: nanoFramework.Device.OneWire (latest)

Issue

OneWireHost.FindAllDevices() always returns 0 devices
with DS18B20 sensor.

Hardware confirmed working

• GPIO17 as OUTPUT writes 0V (LOW) and 3.31V (HIGH)
  correctly on DATA line ✅
• Pull-up 4.7kΩ between DATA and 3.3V ✅
• Bridge GPIO16 ↔ GPIO17 confirmed with multimeter ✅
• Two different DS18B20 sensors tested ✅
• COM1 (GPIO4/5) and COM2 (GPIO16/17) both tested ✅

Code

Configuration.SetPinFunction(16, DeviceFunction.COM2_RX);
Configuration.SetPinFunction(17, DeviceFunction.COM2_TX);
Thread.Sleep(2000);
var oneWire = new OneWireHost();
var devices = oneWire.FindAllDevices();
// devices.Count always = 0

Note

ESP32_S3 firmware does NOT include OneWire support →
ESP32_S3_OCTAL is the only viable target for this hardware.

Is this a known bug? Any workaround available?

[josesimoes]

Can you see proper 1-Wire signaling on the bus?

[Joe9899]

Hi José,
sorry for my late reply. Yes, the signal is present. The command OneWireHost.FindAllDevices() now detects the DS18B20. It was a really silly mistake. I’m using a breakout board that has separate GNDs—one for 5V and one for 3.3V. The 3.3V GND is only connected to the ESP’s pin. I had simply used the wrong GND. Thanks for your reply.

[josesimoes]

No problem. Glad that you've sorted it out.
And that is had nothing to do with nanoFramework. 😉