Onewire, Wifi, MQTT, crash...

[JF002]

Hi!

I finally had the time to go further with my project with the Lopy : reading temperature from a DS18B20 (onewire) sensor, and send it to my MQTT broken on the LAN via WIFI.

Ok, I manage to read the temperature by using the code from this forum post : https://forum.pycom.io/topic/303/ds18b20-temperature-sensor. It works perfectly, I can leave it running for a long time without any issue.

Wifi is quite straightforward, and I used this a MicroPython library for MQTT : https://pypi.python.org/pypi/micropython-umqtt.simple/1.3.2. I did a simple test program that send a value on the broker, and it can run forever too.

But... when I read the temperature and send it on MQTT in a loop... it freezes after 2-3 minutes.

On a firmware version from late december 2016 (1.4 or 1.5 something), a lot of messages were printed on the console when it crashed :

Running temperature_wifi_app.py
Soft resetting the LoPy
Connecting to WIFI...
I (10786) wifi: mode : sta (24:0a:c4:00:c0:52)
I (12716) wifi: n:13 0, o:6 0, ap:255 255, sta:13 0, prof:6
I (13690) wifi: state: init -> auth (b0)
I (13693) wifi: state: auth -> assoc (0)
I (13697) wifi: state: assoc -> run (10)
I (13710) wifi: connected with Zataboy-2.4Ghz, channel 13
WIFI OK
Connecting to MQTT
MQTT OK
Init temperature sensor..
I (24082) wifi: pm open, type:0, st: 0, sending null data: 0

E (306439) wifi: error malloc bcn_param

E (306542) wifi: error malloc bcn_param

E (306644) wifi: error malloc bcn_param

E (306747) wifi: error malloc bcn_param

E (306849) wifi: error malloc bcn_param

E (306951) wifi: error malloc bcn_param

E (308078) wifi: error malloc bcn_param

E (308180) wifi: error malloc bcn_param

E (308283) wifi: error malloc bcn_param

E (308385) wifi: error malloc bcn_param

E (308487) wifi: error malloc bcn_param

E (308590) wifi: error malloc bcn_param

E (310023) wifi: error malloc bcn_param

E (310126) wifi: error malloc bcn_param

E (310228) wifi: error malloc bcn_param

E (311355) wifi: error malloc bcn_param

E (311457) wifi: error malloc bcn_param

[[[ EDIT : a lot more of this message]]]

E (413652) wifi: error malloc bcn_param

E (413754) wifi: error malloc bcn_param

E (414983) wifi: error malloc bcn_param

E (415085) wifi: error malloc bcn_param

E (415188) wifi: error malloc bcn_param

E (415290) wifi: error malloc bcn_param

E (415392) wifi: error malloc bcn_param

E (416621) wifi: error malloc bcn_param

E (416724) wifi: error malloc bcn_param

E (416826) wifi: error malloc bcn_param

E (416928) wifi: error malloc bcn_param

E (417031) wifi: error malloc bcn_param

I (417142) wifi: state: run -> auth (2c0)
I (417142) wifi: n:13 0, o:13 0, ap:255 255, sta:13 0, prof:6
I (417144) wifi: pm close, st: 7, sending null data: 0, total sleep time: 0/393061512

I (417264) wifi: n:13 0, o:13 0, ap:255 255, sta:13 0, prof:6
I (417264) wifi: state: auth -> auth (b0)
I (417267) wifi: state: auth -> assoc (0)
I (417270) wifi: state: assoc -> run (10)
I (417283) wifi: connected with Zataboy-2.4Ghz, channel 13
Traceback (most recent call last):
  File "<stdin>", line 39, in <module>
  File "mqtt/mqtt_simple.py", line 110, in publish
OSError: [Errno 113] EHOSTUNREACH
>
MicroPython v1.8.6-264-gadacebe on 2016-12-22; LoPy with ESP32
Type "help()" for more information.
>>> I (427271) wifi: pm open, type:0, st: 0, sending null data: 0   

I've just upgraded to firmware version 1.6.1.b1. It still crashes, with no message on the console.

Here is the code of the full application:

from network import WLAN
from mqtt.mqtt_simple import MQTTClient

import machine
import time
import sys  
sys.path.insert(0, '/flash/DS18B20')
import ds18x20, machine

print("Connecting to WIFI...")

wlan = WLAN(mode=WLAN.STA)
wlan.connect("Zataboy-2.4Ghz",  auth=(WLAN.WPA2,  "AZERTYUIOP"))

while not wlan.isconnected():
	time.sleep(1)

print("WIFI OK")

print("Connecting to MQTT")

client = MQTTClient("lopy",  "192.168.1.109",  port=1883)
    
client.connect()

print("MQTT OK")

print("Init temperature sensor..")

temp = ds18x20.DS18X20(machine.Pin('G22',machine.Pin.OPEN_DRAIN, machine.Pin.PULL_UP))


tempValue = 0.0
while True:
    tempValue = temp.read_temp()
    client.publish("/test",  str(tempValue))
    time.sleep(1)

I copied the code for onewire/ds18b20 in my Github repo : https://github.com/JF002/lopy-snippets/tree/master/DS18B20.
And the MQTT library : https://github.com/JF002/lopy-snippets/tree/master/mqtt

Do any of you experience this kind of error? What could I try in order to fix this?

Thanks for your help!

[JF002]

The freeze with gc.collect seems to be a bug in the firmware. @daniel is already working on it : https://forum.pycom.io/post/4219

[JF002]

@livius Yes, there is a resistor between 3.3V and the data pin.

[livius]

@JF002
did you use also pullup resistor?

[JF002]

It's a DS18B20. It looks like a transistor, and is not waterproof. Here is an example : https://tushev.org/images/electronics/arduino/ds18x20/DS18B20.jpg

EDIT : after a closer look, it's a DS1820 (w/o the B). Does it change anything?

I tried to connect the DATA pin on G17 (P10) and G22, with no luck.

Did you try the gc.collect thing on this version of the firmware?

[livius]

@JF002
yes, it work for me
which sensor do you have - waterproof?
but i use both and work for me

example data i got:

[UID=24:0a:c4:00:6e:c2] 2162, 22, 35, 0
[UID=24:0a:c4:00:6e:c2] 2162, 23, 35, 0
[UID=24:0a:c4:00:6e:c2] 2162, 24, 35, 0
[UID=24:0a:c4:00:6e:c2] 2162, 25, 35, 0
[UID=24:0a:c4:00:6e:c2] 2162, 26, 35, 0

first is from ds18X20 waterproof
21,62 C

[JF002]

Thank you @livius for you help. I didn't know there was an example for this in the repo from Pycom.

Anyway, I tried the OneWire and DS18X20 modules, but it always returns 60.25 or -7.5... while the ambient temperature should be around 19°C for now... Is this example working for you?

As for the memory, I used gc.mem_free() to see the available RAM memory, and as you said, it dropped very quickly. So, gc.collect() could be a workaround, but it just seem to freeze the Lopy... (it does not respond and I have to reset it with the reset button).

I'm using firmware version 1.6.1.b1.

[livius]

@JF002 said in Onewire, Wifi, MQTT, crash...:

for ds18b20 look here:
https://github.com/pycom/pycom-libraries/tree/master/examples/onewire

there are few fixes (some mine ;-) ) e.g. for negative temperature
and working with many roms
also look at not merged pull request
https://github.com/pycom/pycom-libraries/pull/2/files

you then can worok with driver with many roms and with float or integer calculations

I recommend use gc.collect() because mqtt use more big amout of memory
and i suppose you go into 0 free mem
look at free mem:
gc.mem_free()