I had some issues with my sensor and these pins worked for me but my sensor is really bad.
What pins are you using?
So you changed line 0x55 to 0xFF, right?
You can try adding a few lines to see what’s going on.
Add this line:
frame[pos] = read();
ESP_LOGD("Hex", "Hex: %X", frame[pos]); // <<<<<<<<<< THIS LINE
What board are you using? I’m using a node mcu.
ESP32
How long does it take until the next reading?
Did you change the PollingComponent?
PollingComponent(1000),
Feels right, must return 1.638 / 10 = 163 cm
Post the yaml and .h file codes so we can see what you changed
#include "esphome.h"
class AJ_SR04M_Sensor : public PollingComponent, public UARTDevice, public Sensor {
public:
AJ_SR04M_Sensor(UARTComponent *parent) : PollingComponent(1000), UARTDevice(parent) {}
void update() override {
byte frame[5];
int pos = 0;
float value = 0.0;
write(0xff); // Try this
//delay(1);
// write(0x00);
// delay(1);
//write(0xFF);
delay(86);
while (available()) {
frame[pos] = read();
ESP_LOGD("Hex", "Hex: %X", frame[pos]);
pos++;
if (pos == 4) {
if ((frame[0] == 0xFF) && (((frame[0] + frame[1] + frame[2]) & 0x00FF) == frame[3])){
value = ((frame[1] << 8) + frame[2])/10.0;
publish_state(value);
}
break;
}
}
}
};
esphome:
name: esphome-web-37188b
includes:
- AJ_SR04M_Sensor.h
esp8266:
board: esp01_1m
logger:
api:
ota:
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
ap:
ssid: "Esphome-Web-37188B"
password: "T2MCrnwGgqO2"
captive_portal:
uart:
id: uart_bus
tx_pin: GPIO2
rx_pin: GPIO0
baud_rate: 9600
stop_bits: 1
rx_buffer_size: 4
debug:
dummy_receiver: True
sensor:
platform: custom
lambda: |-
auto my_sensor = new AJ_SR04M_Sensor(id(uart_bus));
App.register_component(my_sensor);
return {my_sensor};
sensors:
unit_of_measurement: cm
accuracy_decimals: 2
name: “Distance”
force_update: true
“Distance is still unknown”
Remove:
If you start getting constant readings play around with the PollingComponent, always greater than 85
Remove this to
Still nothing. It takes a lot of output (0xFF) to get a single input.
I don’t know why yours is sending so many outputs.
The only thing I can think of is that it’s not passing validation on the line:
if ((frame[0] == 0xFF) && (frame[4] == 0x00) && (((frame[0] + frame[1] + frame[2]) & 0x00ff) == frame[3])){
but it should pass
Add these two lines to confirm:
if (pos == 4) {
ESP_LOGD("Validation", "pos == 4"); // ADD THIS LINE
if ((frame[0] == 0xFF) && (frame[4] == 0x00) && (((frame[0] + frame[1] + frame[2]) & 0x00ff) == frame[3])){
ESP_LOGD("Validation", "SUM"); // ADD THIS LINE
value = ((frame[1] << 8) + frame[2]) / 10.0;
I couldn’t make it work on the esphome but now I made it work on a rpi using python script, in thonny. I made some changes to the code for A02 ultrasonic sensor from dfrobot
Library file
'''!
@file DFRobot_RaspberryPi_A02YYUW.py
@brief Ranging distance sensor。
@copyright Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
@license The MIT License (MIT)
@author Arya([email protected])
@version V1.0
@date 2021-08-30
@url https://github.com/DFRobot/DFRobot_RaspberryPi_A02YYUW
'''
import serial
import time
class DFRobot_A02_Distance:
## Board status
STA_OK = 0x00
STA_ERR_CHECKSUM = 0x01
STA_ERR_SERIAL = 0x02
STA_ERR_CHECK_OUT_LIMIT = 0x03
STA_ERR_CHECK_LOW_LIMIT = 0x04
STA_ERR_DATA = 0x05
## last operate status, users can use this variable to determine the result of a function call.
last_operate_status = STA_OK
## variable
distance = 0
## Maximum range
distance_max = 4500
distance_min = 0
range_max = 4500
def __init__(self):
'''
@brief Sensor initialization.
'''
self._ser = serial.Serial("/dev/ttyUSB0", 9600)
if self._ser.isOpen() != True:
self.last_operate_status = self.STA_ERR_SERIAL
def set_dis_range(self, min, max):
self.distance_max = max
self.distance_min = min
def getDistance(self):
'''
@brief Get measured distance
@return measured distance
'''
self._ser.write(b'\xFF')
self._measure()
return self.distance
def _check_sum(self, l):
return (l[0] + l[1] + l[2])&0x00ff
def _measure(self):
data = [0]*4
i = 0
timenow = time.time()
while (self._ser.inWaiting() < 4):
time.sleep(0.01)
if ((time.time() - timenow) > 1):
break
rlt = self._ser.read(self._ser.inWaiting())
#print(rlt)
index = len(rlt)
if(len(rlt) >= 4):
index = len(rlt) - 4
while True:
try:
data[0] = ord(rlt[index])
except:
data[0] = rlt[index]
if(data[0] == 0xFF):
break
elif (index > 0):
index = index - 1
else:
break
#print(data)
if (data[0] == 0xFF):
try:
data[1] = ord(rlt[index + 1])
data[2] = ord(rlt[index + 2])
data[3] = ord(rlt[index + 3])
except:
data[1] = rlt[index + 1]
data[2] = rlt[index + 2]
data[3] = rlt[index + 3]
i = 4
#print(data)
if i == 4:
sum = self._check_sum(data)
if sum != data[3]:
self.last_operate_status = self.STA_ERR_CHECKSUM
else:
self.distance = data[1]*256 + data[2]
self.last_operate_status = self.STA_OK
if self.distance > self.distance_max:
self.last_operate_status = self.STA_ERR_CHECK_OUT_LIMIT
self.distance = self.distance_max
elif self.distance < self.distance_min:
self.last_operate_status = self.STA_ERR_CHECK_LOW_LIMIT
self.distance = self.distance_min
else:
self.last_operate_status = self.STA_ERR_DATA
return self.distance
Ultrasonic loop
# -*- coding:utf-8 -*-
'''!
@file demo_get_distance.py
@brief Get ranging data.
@n Connect board with raspberryPi with TTL to USB adapter
@n
@n
@Copyright Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
@license The MIT License (MIT)
@author [Arya]([email protected])
@version V1.0
@date 2019-8-31
@url https://github.com/DFRobot/DFRobot_RaspberryPi_A02YYUW
'''
import sys
import os
import time
sys.path.append(os.path.dirname(os.path.dirname(os.path.realpath(__file__))))
from DFRobot_RaspberryPi_A02YYUW import DFRobot_A02_Distance as Board
board = Board()
file='/home/rpi/q.wav'
file_wav=wave.open(file)
frequency=file_wav.getframerate()
mixer.init(frequency=frequency)
mixer.music.load("q.wav")
mixer.music.set_volume(1)
def print_distance(dis):
if board.last_operate_status == board.STA_OK:
print("Distance %d cm" %dis)
elif board.last_operate_status == board.STA_ERR_CHECKSUM:
print("ERROR")
elif board.last_operate_status == board.STA_ERR_SERIAL:
print("Serial open failed!")
elif board.last_operate_status == board.STA_ERR_CHECK_OUT_LIMIT:
print("Above the upper limit: %d" %dis)
elif board.last_operate_status == board.STA_ERR_CHECK_LOW_LIMIT:
print("Below the lower limit: %d" %dis)
elif board.last_operate_status == board.STA_ERR_DATA:
print("No data!")
if __name__ == "__main__":
#Minimum ranging threshold: 0mm
dis_min = 260
#Highest ranging threshold: 4500mm
dis_max = 4500
board.set_dis_range(dis_min, dis_max)
while True:
distance = board.getDistance()
print_distance(distance/10)
#Delay time < 0.6s
time.sleep(0.3)
#include “esphome.h”
class AJ_SR04M_Sensor : public PollingComponent, public UARTDevice, public Sensor {
public:
AJ_SR04M_Sensor(UARTComponent *parent) : PollingComponent(1000), UARTDevice(parent) {}
void update() override {
byte frame[5];
int pos = 0;
float value = 0.0;
while (available()) {
frame[pos] = read();
pos++;
if (pos == 4) {
if ((frame[0] == 0xFF) && (((frame[0] + frame[1] + frame[2]) &0x00FF) == frame[3])){
value = ((frame[1] * 256) + frame[2]);
publish_state(value);
}
break;
}
}
}
};
uart:
id: uart_bus
tx_pin: GPIO3
rx_pin: GPIO1
baud_rate: 9600
stop_bits: 1
sensor:
platform: custom
lambda: |-
auto my_sensor = new AJ_SR04M_Sensor(id(uart_bus));
App.register_component(my_sensor);
return {my_sensor};
sensors:
unit_of_measurement: inch
accuracy_decimals: 2
name: “Distance”
filters:
Hi,
i´m a beginner in Home assistent.
I´ve tried to conifgure my AJ-SR04M with a esp8266 like you explained in this post.
Do not work. Can you explain for “dummies” =
Can’t get this to work:
sensor yaml
esphome:
name: upper-water-tank-sensor
friendly_name: Upper Water Tank Sensor
includes:
- AJ_SR04M_Sensor.h
esp32:
board: esp32-s3-devkitc-1
framework:
type: arduino
# Enable logging
logger:
# Enable Home Assistant API
api:
encryption:
key: "PMZ7+0x6HDDjbMO5XVZdutk6YIndcF8DIqN4y0E8xdc="
ota:
password: "7a72e32750314e115482f2dfb1b6d6c0"
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
manual_ip:
static_ip: 192.168.15.29
gateway: 192.168.15.1
subnet: 255.255.255.0
dns1: 192.168.1.2
# Enable fallback hotspot (captive portal) in case wifi connection fails
ap:
ssid: "Upper-Water-Tank-Sensor"
password: "7rl3vO1CcCfS"
captive_portal:
uart:
id: uart_bus
tx_pin: GPIO17 # Connect to DYP RX
rx_pin: GPIO16 # Connect to DYP TX
baud_rate: 9600
stop_bits: 1
rx_buffer_size: 4
debug:
sensor:
- platform: wifi_signal
name: upper_water_tank_wifi
update_interval: 600s
unit_of_measurement: '%'
filters:
- lambda: |-
if (x <= -100) {
return 0;
} else {
if (x >= -50) {
return 100;
} else {
return 2 * (x + 100);
}
}
- platform: template
name: upper_water_tank_volume
id: upper_water_tank_volume
icon: 'mdi:water'
unit_of_measurement: 'l'
accuracy_decimals: 0
- platform: template
name: upper_water_tank_percent
id: upper_water_tank_percent
icon: 'mdi:water-percent'
unit_of_measurement: '%'
- platform: custom
lambda: |-
auto my_sensor = new AJ_SR04M_Sensor(id(uart_bus));
App.register_component(my_sensor);
return {my_sensor};
sensors:
unit_of_measurement: cm
accuracy_decimals: 2
name: "Distance"
sensor file
#include "esphome.h"
class AJ_SR04M_Sensor : public PollingComponent, public UARTDevice, public Sensor {
public:
AJ_SR04M_Sensor(UARTComponent *parent) : PollingComponent(1000), UARTDevice(parent) {}
void update() override {
byte frame[5];
int pos = 0;
float value = 0.0;
write(0x55);
while (available()) {
frame[pos] = read();
pos++;
if (pos == 4) {
if ((frame[0] == 0xFF) && (frame[4] ==0x00) && (((frame[0] + frame[1] + frame[2]) & 0x00FF) == frame[3])){
value =(frame[1] + frame[2]) / 10.0;
publish_state(value);
}
break;
}
}
}
};
The helper board has a blue flashing light and the output logs show
any ideas?
