OneWireHub on ESP32 PROBLEM

[lisdaniel]

OneWireHub on ESP32 PROBLEM

[eychei]

Hi,

I did have the same issue and tried so many options to get this working.
The library just works fine with my esp8266 but not with my esp32.
Error was always:

error: call to non-constexpr function 'uint32_t getCpuFrequencyMhz()'

So looking into
\Arduino15\packages\esp32\hardware\esp32\2.0.6\cores\esp32\Arduino.h
and comparing to
\Arduino15\packages\esp8266\hardware\esp8266\2.7.4\cores\esp8266\Arduino.h

I found the difference in the following line
esp8266:
#define clockCyclesPerMicrosecond() ( F_CPU / 1000000L )
esp32:
#define clockCyclesPerMicrosecond() ( (long int)getCpuFrequencyMhz() )

and here is the SOLUTION:

Open File:
\Arduino15\packages\esp32\hardware\esp32\2.0.6\cores\esp32\Arduino.h
change
#define clockCyclesPerMicrosecond() ( (long int)getCpuFrequencyMhz() )
to
#define clockCyclesPerMicrosecond() ( F_CPU / 1000000L )

Thats it now it compiles without errors.

-e

[GeorgeIoak]

Relying on the fact that the GPIO_DEBUG_PIN should go low for 1ms upon bootup I experimented with changing VALUE_IPL and found that by changing from the default of 39 to 51 I was able to dial the pulse width to 1.0ms:

The code is now working as expected on this old ESP32_DEVKIT_V1 module with flash frequency set to 80MHz and CPU frequency set to 240MHz in the Arduino IDE.

[GeorgeIoak]

I ran into this problem trying to get OneWireHub running on a ESP32. Although the change mentioned does allow the code to compile I cannot get it to work on a ESP32 (2 different boards). If I switch to an old Arduino board the code and hardware works as expected but I need OneWireHub running on a ESP32 for it's WiFi.

The Readme says this works with ESP32 but perhaps some changes have broken that ability?

[GeorgeIoak]

In the readme I saw this comment:

during hub-startup it issues a 1ms long high-state (you can check the instruction-per-loop-value for your architecture with this)

So I hooked up a scope and checked and I'm measuring a pulse at boot up of 1.3ms instead of 1ms with a ESP32 Dev Module:

I tried to run the calibration but that just kept throwing panic errors.

I have this hooked up to a master and I was under the impression that I should get more pulses but that's not happening, only the initial one during boot up.