Hi,
With our HL7692’s and HL7800’s, I’ve been trying the following two commands:
+KSIMSEL Command: SIM Selection
+KSIMDET Command: SIM Detection
I see some odd behaviour. At least, compared with what the following two Sierra AT command guide documents indicate. Below, I describe that odd behaviour, in context. Can anyone shed any light ?
AirPrime_HL76xx_AT_Commands_Interface_Guide_Rev13_0.pdf
AirPrime - HL78xx - AT Commands Interface Guide - Rev10.pdf
With our HL7692’s, I’ve tried the firmware version they came with, 2.23, and also the 2.27 latest. Similarly, with our HL7800’s, I’ve tried the firmware version they came with, 1.7.14, and also the 4.3.9.0 latest.
Best regards,
David
1 HL7692
The following is with 2.27 latest firmware. The same with 2.23 firmware, except in one case where noted.
1.1 SIM selection
Querying the supported modes as follows returns as shown:
AT+KSIMSEL=?
+KSIMSEL: (0-4),(1-8,10-11,13-15)
Good, this accords with what the guide says:
Issuing then a read command as follows returns as shown. So accords with the guide indication of mode 0 as default.
AT+KSIMSEL?
+KSIMSEL: 0
The guide says ‘mode and GPIO settings are saved in non-volatile memory over module reboot.’
Issuing though a write command of mode 4 (read SIM cards presence status) as follows returns ERROR as shown.
AT+KSIMSEL=4
ERROR
However, if I first select one of the other modes (1 2 or 3) as below, then mode 4, it returns as shown:
AT+KSIMSEL=1 AT+KSIMSEL=2 AT+KSIMSEL=3
OK OK OK
AT+KSIMSEL=4 AT+KSIMSEL=4 AT+KSIMSEL=4
+KSIMSEL: 4,0,1 +KSIMSEL: 4,0,1 +KSIMSEL: 4,0,1
The 4 presumably echoes the command. Per the guide, the 0 means external SIM 1 absent, the 1 means external SIM 2 present. In our circuit, the HL7692 default GPIO6 pin for SIM selection is not connected. Presumably the idea is that the HL7692 drives the chosen GPIO pin low or high, with respective SIM 1 or 2 to be externally mux-connected to the HL7692 U1M1 SIM pins. Or vice-versa.
So the first oddity, is why the HL7692 is considering the SIM to be number 2 ? In particular, given that the guide says ‘When SIM select feature is disabled, only the 1st external SIM interface is available and the dedicated GPIO is free for customer use via +KGPIO.’
With 2.23 firmware, +KSIMSEL: 4,1,1 is received instead, which means the HL7692 thinks both SIMs present (!)
I’ve checked, and there’s nothing in the release note for 2.26 or 2.27 about a fix to KSIMSEL.
1.2 SIM detection
In our circuit, the HL7692 U1M1_DET SIM inserted detection pin is connected just to a test point. But for what it’s worth, I issued commands as follows, with responses as shown. Per the guide, the commands mirror the KSIMSEL syntax. 0 means disable SIM detection, 1 means enable SIM detection, being the guide default. I have no idea why the ERROR response happens. The guide says OK should be obtained.
AT+KSIMDET=? AT+KSIMDET? AT+KSIMDET=0 AT+KSIMDET=1
KSIMDET: (0-1) +KSIMDET: 1 ERROR OK
2 HL7800
The following is with 4.3.9.0 latest firmware. With 1.7.14 firmware, all commands shown return error. Possibly the +KSIMSEL and +KSIMDET commands were unimplemented in 1.7.14 firmware.
2.1 SIM selection
Querying the supported modes as follows returns as shown:
AT+KSIMSEL=?
+KSIMSEL: (0,4,9,20)
Good, this accords with what the guide says:
Issuing then a read command as follows returns as shown. So accords with the guide indication of mode 0 as default.
AT+KSIMSEL?
+KSIMSEL: 0,,1
Per the guide, 0 means presently in mode 0. The guide indeed says the default policy is to select External SIM slot on bootup. Also, that mode settings are kept after module reboot. The empty string between the two commas means ‘GPIO SIM selection not supported currently’. And the 1 means external SIM in use, as opposed to 0 for internal SIM.
Issuing though a write command of mode 4 (read SIM cards presence status) as follows returns ERROR as shown.
AT+KSIMSEL=4
ERROR
That’s odd, it should return something like the below. The 4 presumably echoing the command, the first 1 meaning external SIM present, and the second 1 meaning internal SIM present. The empty string between the two commas likewise means GPIO SIM selection not supported currently.
+KSIMSEL: 4,1,,1
Trying a write command of mode 9 (select internal SIM if present) as follows returns as shown. Whether this means our HL7800’s infact lack an internal SIM, or whether the command is just broken, I don’t know.
AT+KSIMSEL=9
ERROR
Anyone know how I can find out in another way, if our HL7800’s have an internal SIM ?
This forum post seems to suggest that some HL7800 SKU’s omit the internal SIM. I don’t know the SKU for our present HL7800’s, as yet at least. But we have 100 incoming with SKU 1104526. Anyone know from that SKU, if the 100 have an internal SIM ?
Trying a write command of mode 20 (select external SIM if present) as follows likewise returns ERROR as shown.
AT+KSIMSEL=20
ERROR
Intriguingly though, trying a write command of mode 0 (force to select external SIM) as follows returns as shown. Ie the command works, albeit keeping the mode as 0.
AT+KSIMSEL=0
OK
2.2 SIM detection
Likewise for what it’s worth, I issued commands as follows, responses as shown. Per the guide, the commands mirror the KSIMSEL syntax. 0 means disable SIM detection, 1 means enable SIM detection, being the guide default. So why the +KSIMDET: 0 response, I wonder ?
AT+KSIMDET=? AT+KSIMDET? AT+KSIMDET=0 AT+KSIMDET=1
KSIMDET: (0-1) +KSIMDET: 0 OK OK