search

bogde / HX711

An Arduino library to interface the Avia Semiconductor HX711 24-Bit Analog-to-Digital Converter (ADC) for Weight Scales.
MIT License
876 stars 535 forks source link

is_ready function broken for espressif microcontrollers after #193 #222

Open ayushsharma82 opened 2 years ago

ayushsharma82 commented 2 years ago

Hi @bogde & @Simonas0 ,

The ‘is_ready’ function of library is broken for Espressif chips (ESP32 & ESP8266) after merger of #193 pull request. Is there any other way by which we can detect if HX711 is present?

Thanks, Ayush

bogde commented 2 years ago

so you mean setting DOUT to INPUT breaks the is_ready function? did you test by editing src/hx711.cpp and changing #define DOUT_MODE INPUT under #ifdef ARCH_ESPRESSIF to #define DOUT_MODE INPUT_PULLUP and it worked?

ayushsharma82 commented 2 years ago

I did some more research, the function works fine when the HX711 is connected with MCU.

In my application, the HX711 is a pluggable external module, so I'm particularly using the is_ready function to detect if HX711 is connected to MCU or not. The problem is due to the is_ready function checking for DOUT line to be LOW. With the recent merge of #193, the DOUT line remains floating when no HX711 board is connected hence the false value of true is returned.

Possible Solution: We can have an is_connected function that checks the DOUT line for a short period with INPUT_PULLUP?

ayushsharma82 commented 2 years ago

so you mean setting DOUT to INPUT breaks the is_ready function? did you test by editing src/hx711.cpp and changing #define DOUT_MODE INPUT under #ifdef ARCH_ESPRESSIF to #define DOUT_MODE INPUT_PULLUP and it worked?

Tested with v0.7.4, that was before #193, so technically yes. The is_ready function works fine when used with INPUT_PULLUP to detect if the module is present or not.

Ben17028 commented 2 years ago

is_ready doesn´t work correctliy in 0.7.5 @ andurino UNO. Software pullup the DOUT pin does not fix it. In 0.7.4 it works fine.

andreash-esp commented 1 year ago

The wait_ready_timeout() function is broken as well in 0.7.5 for ESP32.

This code triggers "HX711 detected" even when no HX711 is attached:

scale.begin(hx711_dt_pin, hx711_sck_pin); if (scale.wait_ready_timeout(1000)) { // check for HX711 scale.power_up(); Serial.println("HX711 detected"); }

The code is working fine in 0.7.4. Build environment is arduino-esp32 1.0.6