EHS5: sysstart not sent | Telit Cinterion IoT Developer Community
July 26, 2016 - 11:59am, 3541 views
at the moment I am facing a serious problem concerning EHS5.
EHS5 does not send sysstart, even though CTS0 (probably*) indicates that ASC0 interface is ready.
EHS5 shall work as a slave. It is supplied with 3,7V @ 600mA using ~150mA at ***. I tried with 2000mA but it is the same result.
I tried RX and TX lines (yes, they are connected correctly, I simulated the uC with an FTDI cable connected the other way round). RX line works correctly from uC to EHS5 (incl. levelshifters), my logic analyzer says I send AT from uC.
Level shifters in TX line are working correctly (I tried this), but EHS5 does not send anything. The rest of startup behavior mentioned in Hardware Interface Description for ASC0 is (probably*) correct.
Probably* means: See the attached picture. Yellow line is the TX and the other is CTS0. The little spike in TX looks like a discharge of a capacitor. So I think the module is turned off and on again, then java crashes and sysstart is never sent. I even waited 3 seconds from CTS0_low for sysstart. I tested two boards and both have the same problem. The polarized cap has 150uF.
I hope to get some ideas where I could check next.
Thanks a lot and best regards
You meant SYSSTART, what about SYSLOADING? Are you getting it?
Please also let me know how you start the module?
thank you for your reply!
I have checked with an oscilloscope but it didn’t read anything. The device sends no SYSLOADING either.
I am using the sequence like in "using Auto-On" but have also tried the "using continuous Auto-On". Both turn on the device in respect to the V180 powering up (I measured 1.8V), leading me to believe the hardware initialization phase completes successfully.
I have waited for anything between 2 and 10 seconds after the CTS0 signal before sending the first AT\r\n.
I have successfully reset the device using pin 33 “EMERG_RST".
Thanks a lot and best regards,
What about HW flow controll? Do you have RTS and CTS lines connected? HW flow controll is obligatory on this module. You can simulate it by shortenning RTS & CTS. Please keep in mind that in this configuration you will not be able to use power saving.
Please also keep in mind that 150mA is ok for the module to start, but if you will register to the network it may need even more than 2000mA. Nevertheless in such a case you will get initial messages (SYS...) and if module, during registration will need more current then provided, it will reboot.
Btw. I don't know why, but the second image is broken. At least on my view.
I didn't upload a second image.
OK. So this is odd. I will report this to portal administration. Thanks.