Is the external power port already soldered?
There is a new footprint for a surface mount right-angle JST connector on the bottom of the board for external 5V sources. The connector doesn't come with the HAT.
With which SIM cards can I use this HAT?
It depends on the module connected to the HAT. Any SIM compatible to the module should be used. Module OEM site would provide more details on it.
Is it possible to use with USB without using GPIO pins? How will the power and data communication be?
Yes, it can be used standalone over the micro USB, with or without stacking on the Raspberry Pi. The maximum data rate will be lower than that of USB.
How do I use the UART connection?
Is it possible to stack two of the HATs?
Yes, you can stack two or more of the HATs with your Raspberry Pi.
Is there a way to use the HAT without using the USB cable at all?
Yes, it can be used via UART.
What is the difference between long header option to the others?
The HAT comes with a built-in SMD header acceptable and two headers with different lengths included in the package by default. You can choose the right version for the project and stack and use it immediately without soldering it.
1. Long Header: If you plan to attach another Raspberry Pi HAT or add-on board on top of the Base HAT, you will need this variation. Also, using GPIOs with jumper cables is possible with these male headers. If you need to stack another HAT on top of Base HAT or use GPIOs, the long header will be useful.
2. Short Header: With the short header no other HAT or sensor can be attached to the GPIO of the Raspberry Pi.
3. Without Header: If plugging the Base HAT via micro USB cable to Raspberry Pi is enough for you, or you’ve already attached a bulky shield/HAT on Pi, it doesn’t need UART communication or IOs, headerless HAT works greatly. For knowing what you missing without headers, take a look at the Pinout Diagram of the HAT, these pins will be unconnected.
Can I send AT command via USB?
Yes, you can send AT commands via USB.
Which versions of the Raspberry Pi are HAT compatible with?
The HAT is compatible with all Raspberry Pi which contains a 40W GPIO header.
Can I use it with other USB Cable?
Yes, you can but we don't recommend the usage of long and low-quality micro USB cables between Base HAT and Raspberry Pi. It causes data and power loss. Thus, the cable included the package works greatly.
Is the base HAT compatible with any other 3g/4g/LTE modules except Quectel? (Huawei, Telit, Sierra, etc.)
Generally, different modules' USB, power supply, status led and SIM Card pins match with Quectel's Pinout but it does not mean full compatibility, some features may not work. You can look at the compatible modules from the technical details page.
Which variant of the Quectel LTE EC25 module should I use with the HAT?
First, find the region in the list of variants. If you don't find it in the list, please compare the LTE Bands with that of your region.
Is it possible to use this HAT to send a message (SMS)? How can I do it?
Yes, you can use AT commands to send SMS. You can find SMS related AT commands in section 9 of the AT manual guide.
How much is the internet speed?
This depends on the module you are using with the HAT. As for instance, if Quectel EC25 mini PCIe is used then the speed will be as follows:
- LTE FDD: Max 150Mbps (DL)/Max 50Mbps (UL)
- LTE TDD: Max 130Mbps (DL)/Max 35Mbps (UL)
- DC-HSDPA: Max 42Mbps (DL)
- HSUPA: Max 5.76Mbps (UL)
- WCDMA: Max 384Kbps (DL)/Max 384Kbps (UL)
- EDGE: Max 296Kbps (DL)/Max 236.8Kbps (UL)
- GPRS: Max 107Kbps (DL)/Max 85.6Kbps (UL)
Which operating systems does it work compatible with?
This depends on the module you are using with the HAT. As for instance, if Quectel EC25 mini PCIe is used with then
USB Serial Driver:
- Windows 7/8/8.1/10
- Linux 2.6/3.x/4.1~
Linux qmi wwan Driver:
- 3.x (3.4 or later)/4.1~
Is there any way to reset the module on the HAT without resetting the pi?
The GPIO26 of the HAT can be pulled HIGH and brought to LOW in order to reset the module. This pin can also be used to power off the HAT by pulling it to HIGH.
What is the maximum current, this HAT needs?
The current consumption depends on the module you will be using with the HAT. Please check the datasheet of the respected module that will be used, for power consumption details.
Is it possible to use it with PoE Hat?
Yes, it possible.
Can I power the both the HAT and the Raspberry Pi through the JST connector?
Yes, the power supply through the JST connector can power both the HAT and the Raspberry Pi.
Can I power both Raspberry Pi and the HAT only through the Raspberry Pi USB power supply?
Yes, powering the Raspberry Pi is enough. It will power the attached HAT on it.
Does QMI works via UART?
No, QMI works via USB only.
Is VoLTE possible on the Base HAT?
Yes, the VoLTE is supported by the EC25 module used with the Baes HAT. Make sure it can be done with the SIM card you are using.
Which one among PPP & QMI should I select?
PPP is a data layer communication protocol that is established through the serial port of the modem. These Serial port communication could be either the UART(/dev/ttyS0) or the serial exposed to USB(/dev/ttyUSB3). This serial is also used for both modem commands (AT commands) and responses. This connection is established by dial-up (ATD*99#).
PPP is easy to establish, widely used protocol, and flexible with the devices. PPP may show a drop of the connection while using the AT command set for other functionality of modem.
The LTE radio protocol has native support of TCP/IP and IPv6, so there is no need to actually wrap TCP/IP into PPP over the radio interface. The PPP protocol is just used between the computer and the modem to make the connection look like a legacy dial-up modem-based network connection.
To get rid of the legacy cruft, newer ways to present USB-connected LTE modems like QMI and MBIM have been developed.
Quectel modules offer QMI(Qualcomm MSM Interface) which is established as a real network interface, such as ethernet(typically shows as wwan0). The QMI is also counted among the non-AT protocols which are communicated over /dev/cdc-wdm0 port.
In order to establish a connection, proper qmi/gobinet proxy should be installed, which again depends on the chipset of the module/modem and the kernel of Linux, gets a bit complicated. The QMI offers a more accessible and faster connection compared to the PPP protocol.
We recommend QMI, if you are looking for a faster connection, and for a longer duration.
If you need to establish an internet connection for a short period of time and the date to be transferred is not high, you may stick to PPP.