Arduino MKR NB1500: lukt niet om te verbinden.
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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.