We customized our own development board based on Nordic's Thingy91 development board. Now it's welded, the circuit works, and we've flash demo MQTT_simple and Asset_cracker_v2, including some LTE related programs, but the SIM card doesn't work. The 1.8V output voltage of the chip was not detected, so we want to ask if there is any deficiency in the circuit design. Or what other software configuration is required? Please point the way.
Attached is our schematic diagram.
Hello,
When the sim1 is selected you can remove the R11 and can make the value of R10 is zero. Because at a time one sim can operate.
Also Vpp should be floated. In our design it looks like the following way.
I can see your VPP and VCC both are connected to 1.8V.
Could you please check your connection first from this point of view?
Thanks.
Best Regards,
Kazi Afroza Sultana
Hello,
When the sim1 is selected you can remove the R11 and can make the value of R10 is zero. Because at a time one sim can operate.
Also Vpp should be floated. In our design it looks like the following way.
I can see your VPP and VCC both are connected to 1.8V.
Could you please check your connection first from this point of view?
Thanks.
Best Regards,
Kazi Afroza Sultana
