EHS6 SYSLOADING loop | Telit Cinterion IoT Developer Community
June 28, 2017 - 12:57am, 5411 views
Hi all, I've been attempting to work with the EHS6 but I'm running into some trouble that i was hoping someone could help with. The device powers up using the auto-on pin and outputs ^SYSLOADING roughly every 2 seconds and won't respond to any AT commands which I send over the TX/RX pins. V180 stays constant in the specified range. Vcore starts out in spec but drops to ~0.2V in sync with the sysLoading messages. I don't believe this is due to variations on the Vbatt line as it happens with both a 1S lipo as well as a benchtop supply and from my understanding it doesn't even get far enough along to pull anything over 70mA.
I realized I left the ON pin floating since I am using Auto_on to start. Should I pull ON low or is floating ok if I don't plan on using it?
Hello,
The power source parameters are important. Are you sure that you have met all the requirements form the Hardware Description document? Have you seen the reference design here https://iot-developer.thalesgroup.com/documentation/example-schematic-eh...
Have you connected both BATT+ lines?
The floating ON line should not be a problem here.
Regards,
Bartłomiej
I have seen a similar reference design. My power source has a different cap array (100uF, 33pF,10pF) but otherwise it's similar. It's drawing directly from a 1S lipo so theres no need for a regulator. I'm aware of the minimum 3.3V needed on the Batt+ line but as the device isn't tramsmitting I doubt any current spikes could be dropping the voltage.
Yes, both of the Batt+ lines are connected
I believe I meet all the requirements for the power source but I don't understand the meaning of the following line "Switches the module's power voltages for the power-up and -down procedures." That is handled internally by the ehs6 not by the rest of the board correct?
Could this be a symptom of the chip being over heated during the reflow process?
Hello,
Have you tried to connect oscilloscope to Vbatt to verify that there are no voltage drops?
As I understand you are developing your own hardware and have the bare module without any developer board soldered.
Would it be possible to paste any schematic?
Regards,
Bartłomiej
Can I email you the schematic and board? I don't wish to post it on a public forum.
irst photo is Vbatt in yellow and Vcore in blue.
Second photo is vbatt in yellow and vddlp in blue.
Third and fourth photos are vbatt in yellow and v180 in blue. I don't know what is causing that momentary spike in v180 before it falls.
Had to cut some photos to get through the spam filter.
Vbatt is captured in yellow on all images
First is vcore in blue. Drop happens every ~2.25 seconds
Second is VDDLP which doesn't show any dropping
Third is V180 which exhibits this behavior every ~2.25 seconds as well.
It seems as though the rise in v180 occurs ~100uS before the fall in vcore
I have sent you an email. Please send the schematic as a response to that address.
Thanks,
Bartłomiej
Hello,
we checked your schematics please check when you disconnect COMM_TX i COMM_RX by cutting 2 lines between module and TXS0102 module will be still restarting.
From schematics we cannot check where is Vrtc and V180 connected ...
Best regards
Lukasz
I currently have the same problem with an ELS61-E Connect Shield. I attempted a firmware update using the supplied utility but it never recovered. The USB doesn't enumerate and it just outputs ^SYSLOADING on the serial port. BATT+ lines appear to be stable.
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