Technical FAQ

1. Considering the cost of hardware changes in later phases, it is recommended to pay attention to design requirements of power supply VBAT, SIM and RF in the hardware design phase.
2. The module is an electrostatic sensitive device. It is required to wear electrostatic gloves or an electrostatic bracelet when working with it. Oil or sweat from hands may leave fingerprints on the surface of module, which may impair module appearance and patch quality.
3. Exceeding the supply voltage range may cause permanent damage to the module.

Soft rebooting will not result in any damages, although it may shorten the service life of the memory.
Rebooting by powering down may cause memory data loss.

For customers' production lines, it is recommended to test SIM card detection, network registration, signal strength and various application interfaces; it is not recommended to test throughput.

It supports built-in eSIM currently. Contact Fibocom technical support for details.

The voice call function supports digital audio output. If analog audio output is required, you will need to add an external codec circuit. Sending and receiving SMS are supported.

FOTA remote over-the-air (OTA) firmware upgrade is supported. It is recommended to use FOTA as the upgrade procedure is simple and convenient. In addition, FOAT firmware upgrade (upgrade over AT command) is also supported. Notwithstanding the foregoing, in any case, the system integrator (OEM) decides the appropriate method applied in respect of any usage of FOTA.

ECM refers to the Ethernet Networking Control Model, which is used to transfer ethernet packets between the device and the host. The usbmode modes that currently support ECM include:
18 Diag+Modem+AT+Pipe+ECM+ADB
23 Modem+AT+ECM
33 Diag+Modem+AT+Pipe+ECM

It refers to the ReMoute NETwork, which can initiate data call through the QMICM tool integrated with QMI commands. The usbmode modes that currently support RMNET include:
17 Diag+Modem+AT+Pipe+RMNET+ADB
22 Modem+AT+RMNET
31 Diag+Modem+RMNET+DPL+QDSS+ADB (Reserved QCOM for internal debug only)
32 Diag+Modem+AT+Pipe+RMNET

Two dialing methods are currently supported:
ECM dialing: use AT+GTRNDIS;
RMNET dialing: AT$QCRMCALL;

Yes. Most of our LGA/LCC packages support Open Linux development. Please contact Fibocom FAE or our sales representative for details.

Our module provides the drivers and instructions for Windows, Linux, and Android. Please contact Fibocom FAE or our sales representative for details.

128GB

As an example to flash the boot partition:
adb reboot bootloader // Reboot the system and enter fastboot mode
fastboot flash boot D: \ boot.img // flash the boot partition
fastboot reboot // Reboot the system

The mobile computing smart module generally supports SIM card hot swapping. Specifically, the support for SIM card hot swapping depends on the MODEM side. Please consult Fibocom technical support for details if necessary.

There is feedback for both forward and reverse insertions of the SIM card holder of the mobile computing smart module development board. Please pay attention to the shape of the SIM card holder and insert the card according to the notch orientation. Note that the contact point of the SIM card should touch the contact point on the PCB. The SIM card notch on the current development board is facing outward.

Low noise amplifiers and SAW filters are added in the internal GPS of some modules, such as our smart module SC820.

1. If the DC power supply is used, the battery temperature detection pin should be connected to a 10K resistor and pulled down. (The temperature detection pin is the pin in the middle of the battery interface.)
2. If you use a battery with a temperature detection pin, the battery will be pulled down by 10K, so you can boot the module normally.

BP
modem NON-HLOS.bin
sbl1 sbl1.mbn
rpm rpm.mbn
tz tz.mbn
AP
aboot emmc_appsboot.mbn
splash splash.img
boot boot.img
system system.img
persist persist.img
cache cache.img
recovery recovery.img
privdata privdata1.img
userdata userdata.img

SC800 / SC806 (msm8909) does not support fast charging.
SC820 (msm8953) does not support fast charging.
SC826 (msm8953) supports fast charging (QC3.0). It depends on whether the specific model has PMI. If a model is provisioned with PMI, it can theoretically support fast charging. Please contact Fibocom technical support for details.

The recommended voltage value for the Fibocom module is 3.8V (refer to the Fibocom hardware manual of specific modules for details); the driver capability must be 3A or above, and ripple must be less than 300mV.

The battery peak discharge capacity is recommended to be 5A, and over-discharge/over-charge protection points need to meet the power supply range of the module. The internal resistance of the battery is recommended to be less than 100 milliohms; batteries with good linearity at high and low temperatures are recommended.

1. Check if the SIM card is activated and check if the 4G/5G service is activated.
2. The data traffic with the SIM card may be service-specific, meaning the SIM card only allows access to specific servers and connection to other servers are unstable or will not work. For example, the NTP server may not be added to the SIM card whitelist.
3. A username and password combination may be required for dedicated network card authentication.
4. The module may not support the network standard.
5. The SIM card may be an IoT card with voice function removed.
6. SIM card charges 7. Other unknown reasons.

The SIM card is a chip that stores user information, and it can only be operated by authorized operators. The physical interface between the chip and the host is a bare metal sheet. After being used for a period of time, the internal data on the SIM card may be corrupted for several reasons, including short circuiting caused by moisture, deformation, static electricity or abnormal power-down.

1. The main cause may be hardware interference, e.g. the wiring of the antenna or RF is next to or close to the SIM card, which might cause interference.
2. The internal data of the SIM card is corrupted. The solution is to replace it with another SIM card from the operator that the module supports.
3. It may be a SIM card compatibility issue. There are many SIM card manufacturers. The internal data in some SIM cards may change after a period of use. Please contact Fibocom FAE to capture the module trace for analysis.
4. It may be related to module operations. For example, frequent rebooting of the module can cause internal initialization errors, which may result in card drop.
5. Mechanical vibrations may cause card drop.

1. First, confirm that the module is powered up properly: for mobile computing smart modules, check the device screen using VDD and LPG detection or by viewing the SIM_VCC waveform.
2. Check if the settings match, including baud rate and traffic control.
3. Check the UART for wireless sequence errors, poor welding, and whether there is short circuit to ground.
4. Check if the levels match.

It may be caused by a large error in the baud rate used by the processor. The module requires a highly accurate baud rate. Correcting the parameter settings on the processor side should solve the problem. It may also be caused by the short circuit to ground of the serial port. It is recommended to compare the waveforms.

Measure the voltage or voltage waveform of the VDD. This is why customers should reserve VDD test points during hardware design.