FAQs
1.1 What is the audio output capability of the module?
The module can drive a maximum 8ohm load resistance if there is an embedded AB amplifier inside it. If there is no embedded AB amplifier in the module, it can drive a maximum 32ohm load resistance. An external audio amplifier is needed to drive 8ohm load resistance
1.2 Why might a call hang up when you use ATD to make a call?
- Check if the MCU has sent an ATH command to end the call
- Check whether there are capacitors with high capacitance (i.e. more than 1uF) in the audio interface. In general, only 10pf and 33pf capacitors can be connected to the audio interface to eliminate RF interference. Capacitors with high capacitance will cause instability to the audio PA, which may lead to a call hanging up
Call
2.1 How should the caller ID and Connected Line Identification Presentation (CLIP) be set up?
- AT+CLIP=1 can be used to present the calling line, and you can set AT+QCLIP=1 to present the string type corresponding to the entry saved in the phonebook
- AT+COLP=1 can be used to present the connected line, and you can set AT+QCOLP=1 to present the string type corresponding to the entry saved in the phonebook
2.2 What should the maximum time be that a module responds with ‘OK’ after executing ATH to hang up a call?
According to the 3GPP standard the maximum time should be 90 seconds. You can set the proper timeout of ATH in the MCU program based on the maximum time.
Flash
3.1 What is the lifetime of the module’s flash memory?
The erasable lifetime of flash memory is generally around 100,000. In order to extend this, we have adopted dynamic reading and writing technology in our modules, which allows data to be written to each section of the flash instead of the same block, so each section has the same chance of being used, which avoids damage to the flash chipset.
MMS
4.1 Can UTF8 and UCS2 coding schemes be supported in the MMS? Which one is better?
Both UTF8 and UCS2 are supported. However, we recommend using UTF8 for better network compatibility.