Hi
I’m having a hard time getting proper timestamp, it only updates after exactly 128 seconds, all-through it should update every seconds, at least I hope this is what my code is doing. When using .seconds it updates properly.
time:
- platform: homeassistant
id: hastime
interval:
- interval: 1s
then:
- lambda: |-
if (id(hastime).utcnow().is_valid()) {
id(timestamp_sec).publish_state(id(hastime).utcnow().timestamp);
id(time_seconds).publish_state(id(hastime).utcnow().second);
}
sensor:
- platform: template
name: "Current time stamp"
id: timestamp_sec
- platform: template
name: "Current time"
id: time_seconds
Here is part of the the output when the timestamp finally updates.
[21:43:24][D][sensor:092]: 'Current time': Sending state 24.00000 with 1 decimals of accuracy
[21:43:25][D][sensor:092]: 'Current time stamp': Sending state 1584927744.00000 with 1 decimals of accuracy
[21:43:25][D][sensor:092]: 'Current time': Sending state 25.00000 with 1 decimals of accuracy
[21:43:26][D][sensor:092]: 'Current time stamp': Sending state 1584927744.00000 with 1 decimals of accuracy
[21:43:26][D][sensor:092]: 'Current time': Sending state 26.00000 with 1 decimals of accuracy
[21:43:27][D][sensor:092]: 'Current time stamp': Sending state 1584927744.00000 with 1 decimals of accuracy
[21:43:27][D][sensor:092]: 'Current time': Sending state 27.00000 with 1 decimals of accuracy
[21:43:28][D][sensor:092]: 'Current time stamp': Sending state 1584927744.00000 with 1 decimals of accuracy
[21:43:28][D][sensor:092]: 'Current time': Sending state 28.00000 with 1 decimals of accuracy
[21:43:29][D][sensor:092]: 'Current time stamp': Sending state 1584927872.00000 with 1 decimals of accuracy
[21:43:29][D][sensor:092]: 'Current time': Sending state 29.00000 with 1 decimals of accuracy
[21:43:30][D][sensor:092]: 'Current time stamp': Sending state 1584927872.00000 with 1 decimals of accuracy
[21:43:30][D][sensor:092]: 'Current time': Sending state 30.00000 with 1 decimals of accuracy
[21:43:31][D][sensor:092]: 'Current time stamp': Sending state 1584927872.00000 with 1 decimals of accuracy
[21:43:31][D][sensor:092]: 'Current time': Sending state 31.00000 with 1 decimals of accuracy
[21:43:32][D][sensor:092]: 'Current time stamp': Sending state 1584927872.00000 with 1 decimals of accuracy
1 Like
behnam85
November 3, 2021, 1:12am
2
I am also facing same issue
Jpsy
November 3, 2021, 5:51am
3
ESPHome uses floats (4 bytes) not doubles (8 bytes) to represent sensor states. The number of digits that can be represented with floats is not sufficient for timestamps. Hence the value seems to jump in steps of 128 (quantization).
The result of utcnow() is in fact a signed int, which can hold all the precision that you need. So any timestamp calculations within your lambda will be correct as long as you don’t convert to float. But you implicitly convert to float when you call publish_state().
I am not an expert in C++ but you could try and use a bit mask to show that the int value of a timestamp changes with each second. Something like…
id(timestamp_sec).publish_state(id(hastime).utcnow().timestamp & 1)
Tip:millis() if you need something that increases every millisecond but has a base value that will fit into a float.
behnam85
November 3, 2021, 9:53am
4
thanks for reply.
Jpsy
November 3, 2021, 10:34am
5
Just from the back of my mind and without testing:
Publish the Unix epoche timestamp in seconds, not in milliseconds.
Make sure to correctly set the device_class of your sensor:device_class: "timestamp"
Something like:
interval:
- interval: 1s
then:
- lambda: |-
if (id(hastime).utcnow().is_valid()) {
id(timestamp_sec).publish_state(id(hastime).utcnow().timestamp / 1000);
}
sensor:
- platform: template
name: "Current time stamp"
id: timestamp_sec
device_class: "timestamp"
UPDATE:Attention! I was very wrong about the seconds! HA in fact expects timestamp sensors in milliseconds . And there seems to be no way around the fact that the Unix epoch values, measured in milliseconds, are to big for C++ floats to store all digits. So you lose some precision when the timestamps arrive in HA (about +/-64 seconds). See below…
behnam85
November 3, 2021, 11:02am
6
thanks for help .
Jpsy
November 3, 2021, 11:05am
7
“51 years ago” means 01.01.1970 – the start of the Unix epoche.
behnam85
November 3, 2021, 11:15am
8
textname: templatexx
#globals:
# - id: timestamp_sec
# type: int
# restore_value: no
# initial_value: '0'
# - id: my_vmin_int
# type: float
# restore_value: no
# initial_value: '250'
esphome:
name: esp321
platform: ESP32
board: lolin32
wifi:
ssid: "Mi wifi"
password: "behnam123"
# Enable fallback hotspot (captive portal) in case wifi connection fails
ap:
ssid: "Esp321 Fallback Hotspot"
password: "coCKxLsID1nI"
captive_portal:
# Enable logging
logger:
level: debug
# 6Enable Home Assistant API
api:
ota:
uart:
rx_pin: 32
baud_rate: 9600
##########################################
# Declare GPS module
gps:
latitude:
name: "Latitude"
longitude:
name: "Longitude"
altitude:
name: "Altitude"
id: a
# GPS as time source
time:
- platform: gps
id: gps_time
on_time:
- seconds: '*'
then:
- lambda: |-
# ESP_LOGI("gps", "%02d:%02d:%02d:%08d",id(gps_time).now().hour, id(gps_time).now().minute, id(gps_time).now().second,id(gps_time).now().timestamp);
# - ESP_LOGI("gphs","%02d-%02d-%02d %02d:%02d:%02d", id(gps_time).now().timestamp);
# ESP_LOGI("gps1" , "%02d-%02d-%02d %02d:%02d:%02d", id(gps_time).now().year, id(gps_time).now().month, id(gps_time).now().day_of_month, id(gps_time).now().hour, id(gps_time).now().minute, id(gps_time).now().second);
- sensor.template.publish:
id: template_sens
state: !lambda
return id(gps_time).now().timestamp;
- text_sensor.template.publish:
id: last_bell_press
state: !lambda |-
char str[20];
time_t currTime = id(gps_time).now().timestamp;
strftime(str, sizeof(str), "%Y-%m-%d %H:%M:%S", localtime(&currTime));
return { str };
interval:
- interval: 1s
then:
- lambda: |-
if (id(gps_time).utcnow().is_valid()) {
id(timestamp_sec).publish_state(id(gps_time).utcnow().timestamp /1000 );
}
sensor:
- platform: template
name: "Current time stamp"
id: timestamp_sec
device_class: "timestamp"
- platform: template
name: "Template Sensor"
id: template_sens
accuracy_decimals: 0
# force_update: true
update_interval: 1s
# device_class: timestamp
#######################################
text_sensor:
- platform: template
name: "Template Text Sensor"
id: last_bell_press
behnam85
November 3, 2021, 11:15am
9
INFO Reading configuration /config/esphome/esp321.yaml…
behnam85
November 3, 2021, 12:01pm
10
I tried a few things to fix this.
if (id(gps_time).utcnow().is_valid()) {
id(timestamp_sec).publish_state(id(gps_time).utcnow().timestamp / 1000 );
to
if (id(gps_time).utcnow().is_valid()) {
id(timestamp_sec).publish_state(id(gps_time).utcnow().timestamp );
but timestamp not updated every second.
Jpsy
November 3, 2021, 12:09pm
11
This is where the discussion started. The state is a float and cannot hold milliseconds back to 1970 with 1 second precision.
You have to publish the timestamp in seconds to HA, not /1000 in the calculation. Why did you remove it?
behnam85
November 3, 2021, 12:21pm
12
before removed it ; entity state :1970-01-19T22:25:41+00:00
Sorry, my English is not good.
Jpsy
November 3, 2021, 1:24pm
13
I stand corrected.
I did some real testing now and there seems to be now way to get around the fact that some precision is lost when you write a timestamp. You lose ±64 seconds of precision.
An option would be to write the timestamp into a text_sensor. But there is no device_class for text_sensors and HA will not interpret this sensor as a time. It is simply a string.
May I ask why you need that timestamp? HA stores each sensor update together with the time anyway.
behnam85
November 3, 2021, 1:44pm
14
Thank you very much for your help.http://demo.traccar.org:5055/?id=123456&lat={0}&lon={1}×tamp={2}&hdop={3}&altitude={4}&speed={5}
behnam85
November 3, 2021, 1:51pm
15
"You lose ±64 seconds of precision "Isn’t this a issues?
Jpsy
November 3, 2021, 2:02pm
16
behnam85:
Isn’t this a issues?
It definitely is.issue report with two proposals how to solve that.
1 Like
