|Pin Number||BCM Pin||Pin Name||Description|
|8||UART_TX||PCI RX||This pin functions as the serial data input to the module for UART communication.|
|10||UART_RX||PCI TX||This pin functions as the serial data output from the module for UART communication|
|13||GPIO27||USER LED||Active HIGH, to switch on the USER LED, the pin's state should be HIGH.|
|15||GPIO22||USER BUTTON||This pin normally pulled-down to ground. When the button is pressed, pin switches to LOW.|
|31||GPIO6||RI||This pin is Ring indicator functions as the indication for receiving call or SMS, can be calibrated to HIGH or LOW using the AT commands.|
|33||GPIO13||DTR||When the module is in sleep mode, DTR pin allows to wake the module up by pulling it to LOW.|
|35||GPIO19||W_DISABLE||This pin is used to turn Airplane Mode on the module, by pulling it HIGH.|
|37||GPIO26||HAT_PWR_OFF||Power regulator control. Normally pulled-down, when this pin drove to HIGH, Hat's power will cut off.|
|Quectel||EC25, LTE-EP06, EC21 , EC20 Mini PCIe LTE IoT Module, UC20 , LTE-EP06|
|Telit||LM960, LE910V2, HE910,LE910C1, LE910C4, and more|
|Thales||PLS62W, mPLS8, mPLAS9|
|Sierra||AirPrime MC Series|
|Huawei||ME909s-120, ME909s-821, and more|
|Simcom||SIM7100, SIM7230, and more|
|ZTE||ZM8620, and more|
If one is looking to use different mini PCIe modules other than the ones mentioned above, it should be compared with the pinout of mini PCIe below. The following mentioned pins are connected to the Base HAT.
- Raspberry Pi 4, 3, 2, B+, A+, Zero i.e. RPi which contains 40W GPIO header.
- Asus Tinker Board
- Rock 64*
- Orange Pi*
- Samsung ARTIK’s Eagleye board*
- Latte Panda
- PWR LED: When the module is powered up, this RED led turns on
- SGNL LED: This BLUE led indicates the status of the connection. When the connection is established and data is being transmitted/received, this led will blink at special intervals. Otherwise, if there is no connection, the led will remain off.
- USER LED: It is a programmable user-led can be controlled from the GPIO27 of Raspberry Pi for debugging or just fun.
- User Button: It is a programmable user button that is connected to GPIO22. Reads HIGH by default.
When you observe the HAT, you will come across some solder Jumpers marked as SJx (SJ1, SJ2, SJ3, etc). These solder jumpers are either connected or disconnected by default. These can be used to enable or disable the default use case. These SJ are provided for the cases where the specific GPIO are conflicting with the users requirement. Disconnecting the jumpers may lead to loss in some programmable feature. For instance, Cutting the SJ4 trace which is RI, Ring Indicator used as indication for call or SMS cannot be used.
Disconnecting: Cut the narrow trace between the middle of these solder jumper with a utility knife.
Connecting/Reconnecting: Solder the jumper to connect the traces.
|Solder Jumper||Corresponding GPIO||Default State||Purpose||Affect of changing the default state|
|SJ1||GPIO26||CONNECTED||Cut to disconnect from HAT_PWR_OFF.||Cannot control the power of the HAT.|
|SJ2||GPIO19||CONNECTED||Cut to disconnect from W_DISABLE.||Cannot disable Wireless communication.|
|SJ3||GPIO13||CONNECTED||Cut to disconnect DTR pin from GPIO.||Cannot use for sleep mode control.|
|SJ4||GPIO6||CONNECTED||Cut to disconnect RI pin from GPIO.||Cannot read the Ring indicator.|
|SJ5||GPIO22||CONNECTED||Cut to disconnect USER BUTTON||Cannot use User Button.|
|SJ6||GPIO27||CONNECTED||Cut to disconnect USER LED||Cannot use User Led.|
|SJ7||RXD||NOT CONNECTED||Solder to connect RX of module. Used to communicate over UART.||-|
|SJ8||TXD||NOT CONNECTED||Solder to connect TX of module. Used to communicate over UART.||-|
With Quectel mini PCIe modules, the Base HAT can be used via USB or UART. Using USB is recommended since the speed slows down via UART compared to the USB. If one still wants to use the UART, the SJ7 and SJ8 needs to be soldered. The Telit module cannot be used via UART with Base HAT. The UART will work with modules where the RX TX are at PCIe pin 11 & 13.
To use the UART follow the steps mentioned in the UART Configuration guide.