Arduino MKR NB1500: lukt niet om te verbinden.
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@Martijn-Kooijman @Stefan-de-Lange
Some news after the update (to 2.04): Lowpower.sleep (or deepSleep) has improved by a factor 2! The current reduced to 0.48 mA, still not very low power but at least an improvement.
The command AT+URAT=8 is not recognized anymore (comunication selection for NB only). It also seems that it sometimes needs a lot of time to open a channel after a deep_sleep (varies between 10 s and >30s which wastes energy). -
@Crowdsourcer Nice, but still far from expected values (7 uA). What do you mean by ‘open a channel’ ? After wake-up from deep sleep the ublox takes at max 4 seconds to wake up, so I wonder what happens in your case.
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@Stefan-de-Lange
Yes, still high, but there are more peripherals (such as the charger IC) so I think something like 50 uA should be expected.
Before sleep I do:
digitalWrite(SARA_PWR_ON, LOW); //to shut down the ubloxAfter sleep I need to switch on the modem and do a reset:
digitalWrite(SARA_PWR_ON, HIGH);
delay(100);
digitalWrite(SARA_RESETN, HIGH);
delay(100); //default 100
digitalWrite(SARA_RESETN, LOW);I first wait about 10 s, then I open a port:
“AT+USOCR=17,7000”
I usually get an error: “+CME ERROR: Operation not allowed”
So I need to repeat this until I get:
+USOCR: 0
That usually takes between 12 and more than 40s.Since URAT is not possible any more, it seems as if it has difficulty selecting NB?
Any recommendations to make this more reliable? -
Yes, still high, but there are more peripherals (such as the charger IC) so I think something like 50 uA should be expected.
50 uA is still high but it depends what you want get out of it ofcourse.
Before sleep I do:
digitalWrite(SARA_PWR_ON, LOW); //to shut down the ubloxThis is not necessary. The ublox can stay in 7uA PSM mode, no need to turn it off unless you plan to stay off for a looong time
After sleep I need to switch on the modem and do a reset:
digitalWrite(SARA_PWR_ON, HIGH);
delay(100);
digitalWrite(SARA_RESETN, HIGH);You should never drive a reset pin, it may damage the board. It’s also not necessary, you can wake it up with PWR_ON pin alone. Use open collector/open drain for both PWR_ON and reset
delay(100); //default 100
digitalWrite(SARA_RESETN, LOW);I first wait about 10 s, then I open a port:
“AT+USOCR=17,7000”
I usually get an error: “+CME ERROR: Operation not allowed”
So I need to repeat this until I get:
+USOCR: 0
That usually takes between 12 and more than 40s.Because the u-blox is attaching to a network. See:
You can wait for +CEREG first, then open a socket.Since URAT is not possible any more, it seems as if it has difficulty selecting NB?
Any recommendations to make this more reliable?This can happen if your FW upgrade package did not come with an EU MNO profile. Check AT+UMNOPROF=?
Check if you see ‘100: Standard Europe’ in the list. If not then you need to ask u-blox for instructions on how to install it. -
@Stefan-de-Lange
-The reset pin is used in the Arduino supplied SerialSARAPassthrough program so that seems fine to use for a reset.
-I did not test PSM, in default configuration it is off.
-I tested AT+UMNOPROF? and it is default 0, I then changed it to 100 (Standard Europe), but AT+URAT is still not available.
-For now after each wake up I do the following sequence (about 14 seconds in total):
AT+CFUN=0
AT+CEREG=3
AT+CFUN=1
wait for “CEREG:…” in a SARA response string
AT+COPS=1,2,“20416”
AT+USOCR=17,7000
check for USOCR: 0
then send data…So far it seems to work fine.
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-The reset pin is used in the Arduino supplied SerialSARAPassthrough program so that seems fine to use for a reset.
Ofcourse you can use it, but not after sleep to wake it up. Hard reset is only used as a last resort when the module is stuck for example.
-I did not test PSM, in default configuration it is off.
If you want to get low power it’s a good idea to use it
-I tested AT+UMNOPROF? and it is default 0, I then changed it to 100 (Standard Europe), but AT+URAT is still not available.
-For now after each wake up I do the following sequence (about 14 seconds in total):
AT+CFUN=0
AT+CEREG=3
AT+CFUN=1
wait for “CEREG:…” in a SARA response string
AT+COPS=1,2,“20416”
AT+USOCR=17,7000
check for USOCR: 0
then send data…So far it seems to work fine.
That looks better. But you don’t have to use AT+COPS, after you see +CEREG: 1 (or 5 if roaming) you are already attached.
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@Stefan-de-Lange
I just tested the SARA PSM setting:
Changed from default 0 to 4: AT+UPSV=4
After about 6 s inactivity it enters sleep mode and requires a dummy character to send to wake it up. I get reliable connection each time (using AT+USOCR=17,7000). So far so good,
however, sleep currents too high now (>10mA) and I also observe regular increases to >40 mA and accidental short drops <1 mA.
So it seems the SARA is consuming much more than your suggested 7uA during sleep time. -
I just tested the SARA PSM setting:
Changed from default 0 to 4: AT+UPSV=4That’s not PSM but power saving. PSM is the network sleep state, you can set it via AT+CPSMS=1 (+timers).
After about 6 s inactivity it enters sleep mode and requires a dummy character to send to wake it up. I get reliable connection each time (using AT+USOCR=17,7000). So far so good,
Good. Just FYI, it’s UDP so there is no ‘connection’, atleast not to the server. You can open a socket and send packets when you are attached but the module will not tell you if they failed to arrive
however, sleep currents too high now (>10mA) and I also observe regular increases to >40 mA and accidental short drops <1 mA.
So it seems the SARA is consuming much more than your suggested 7uA during sleep time.Try AT+CPSMS=1. I measured 6.7 uA, datasheet says 7 uA so you should see similar values
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@Stefan-de-Lange
I tried AT+CPSMS=1 but the Arduino board consumed >15 mA during sleep. No idea why, but I think for the Arduino board it is easiest to just use the power_on pin (note that this is not the power supply pin!). -
@Crowdsourcer said in Arduino MKR NB1500: lukt niet om te verbinden.:
@Martijn-Kooijman @Stefan-de-Lange
Some news after the update (to 2.04): Lowpower.sleep (or deepSleep) has improved by a factor 2! The current reduced to 0.48 mA, still not very low power but at least an improvement.
The command AT+URAT=8 is not recognized anymore (comunication selection for NB only). It also seems that it sometimes needs a lot of time to open a channel after a deep_sleep (varies between 10 s and >30s which wastes energy).I can confirm now that AT+URAT=8 works with the new firmware! Probably because I changed: AT+UMNOPROF=100 (European profile).
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@Crowdsourcer AT+CPSMS=1 enables network PSM so the module can sleep while staying attached to the network. Using the power_on pin just turns the whole module off so you detach and next time you wake up you will have to attach again, both cost energy. In almost all cases using PSM is prefered
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@Stefan-de-Lange
Yes, this is how it should work, and would save a lot of reconnection time, but so far I think >15mA is too much (reconnection time is about 20 s at around 60 mA on average). -
@Crowdsourcer If you see 15 mA it means there is a problem. I measured an average of 6.7 uA in PSM
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Some follow up since last year: My MKR NB1500’s are all running on LiPo’s and the SARA modem is not transmitting any more at voltages below 3.8V. I looked up the schematics of this board and it appears that there is a 3V8 powerline for the SARA modem. However it is not produced anywhere on the board? The SARA modem power requirements state “typical 3.8V” so it could be that my SARA’s are a batch that does not like voltages even slightly lower than 3.8V? Seems like a bad board design? Anyone experiencing the same problems?
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@Crowdsourcer That can be many things. Maybe the LiPo is bad, has too little charge or has too low capacity/current capability? I would suggest to test using a bench power supply and try to steadily lower the voltage. If that also doesn’t work then perhaps the module is faulty
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LiPo is fine (almost new 6000mAh)! I checked the schematics again and it appears that the 3.8V is produced from the LiPo by charge controller BQ24195. This 3.8V is then fed to the SARA modem and a LDO voltage regulator (AP2112) and converted to 3.3V. Seems that something is wrong with this converter, or its configuration?
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@Crowdsourcer I don’t know. BQ24195 is pretty solid. Probe it if you need to.