- The SimShield is an expansion board for the Sim series that includes three-way current detection, LoRa transceiver, and wide-range DC input. It supports the full range of LilyGo T-Sim expansion boards.
Important
Warning: Jumper caps and DIP switches must be checked when power is on. Risk of damage if wrong selection is made
| Features | Details |
|---|---|
| ⚡DC interface allows input voltage | 7~36V |
| ⚡Battery interface allows input voltage | 4.2V |
| ⚡Charge Current | Provided by the motherboard |
| ⚡+5V | The maximum current can be 2A |
| ⚡+3V3 | Provided by the motherboard |
- It is recommended not to connect the +3V3 pin to peripheral devices with a current exceeding 100mA, as different motherboards provide different currents.
- J25 short IO -> LP2
- J21 short RP1 -> 5V
- SW3 is turned to ON, and the remaining SW1, SW2, and SW4 must not be in the ON position.
Important
A7670X/A7608X motherboards, resistors need to be removed to use SimShield. Please refer to this link for instructions on How to remove resistors
SIM7000G does not have this limitation.
| SIM7000G/A7670X/A7608X ESP32 | GPIO |
|---|---|
| SIMSHIELD_MOSI | 23 |
| SIMSHIELD_MISO | 19 |
| SIMSHIELD_SCK | 18 |
| SIMSHIELD_SD_CS | 32 |
| SIMSHIELD_RADIO_BUSY | 39 |
| SIMSHIELD_RADIO_CS | 5 |
| SIMSHIELD_RADIO_IRQ | 34 |
| SIMSHIELD_RADIO_RST | 15 |
| SIMSHIELD_RS_RX | 13 |
| SIMSHIELD_RS_TX | 14 |
| SIMSHIELD_SDA | 21 |
| SIMSHIELD_SCL | 22 |
- J25 short IO -> BAT
- J21 short RP2 -> 5V
- SW3 is turned to ON, and the remaining SW1, SW2, and SW4 must not be in the ON position.
Important
The SIM7600 pin header is 15 pins, and the insertion position must be where the arrow points.
| SIM7600X ESP32 | GPIO | Modem |
|---|---|---|
| SIMSHIELD_MOSI | 23 | |
| SIMSHIELD_MISO | 19 | |
| SIMSHIELD_SCK | 18 | |
| SIMSHIELD_SD_CS | 32 | SIM7600 DTR PIN |
| SIMSHIELD_RADIO_BUSY | 39 | |
| SIMSHIELD_RADIO_CS | 5 | |
| SIMSHIELD_RADIO_IRQ | 34 | SIM7600 STATUS PIN |
| SIMSHIELD_RADIO_RST | 14 | |
| SIMSHIELD_RS_RX | 12 | SIM7600 LED PIN |
| SIMSHIELD_RS_TX | 13 | |
| SIMSHIELD_SDA | 21 | |
| SIMSHIELD_SCL | 22 |
Important
The SIM7600 DTR (IO32), STATUS (IO34), and ON BOARD LED (IO12) have been reassigned to SimShield. Please do not use these three GPIOs for other purposes.
- J25 short IO -> LP2
- J21 short RP1 -> 5V
- SW2 is turned to ON, and the remaining SW1, SW3, and SW4 must not be in the ON position.
| SIM7670G ESP32S3 | GPIO |
|---|---|
| SIMSHIELD_MOSI | 15 |
| SIMSHIELD_MISO | 7 |
| SIMSHIELD_SCK | 16 |
| SIMSHIELD_SD_CS | 46 |
| SIMSHIELD_RADIO_BUSY | 38 |
| SIMSHIELD_RADIO_CS | 39 |
| SIMSHIELD_RADIO_IRQ | 6 |
| SIMSHIELD_RADIO_RST | 40 |
| SIMSHIELD_RS_RX | 41 |
| SIMSHIELD_RS_TX | 42 |
| SIMSHIELD_SDA | 2 |
| SIMSHIELD_SCL | 1 |
- J25 short IO -> LP2
- J21 not connected to any
- SW2 is turned to ON, and the remaining SW1, SW3, and SW4 must not be in the ON position.
| A7608X ESP32S3 | GPIO |
|---|---|
| SIMSHIELD_MOSI | 11 |
| SIMSHIELD_MISO | 10 |
| SIMSHIELD_SCK | 12 |
| SIMSHIELD_SD_CS | 45 |
| SIMSHIELD_RADIO_BUSY | 38 |
| SIMSHIELD_RADIO_CS | 39 |
| SIMSHIELD_RADIO_IRQ | 9 |
| SIMSHIELD_RADIO_RST | 40 |
| SIMSHIELD_RS_RX | 41 |
| SIMSHIELD_RS_TX | 42 |
| SIMSHIELD_SDA | 2 |
| SIMSHIELD_SCL | 1 |
- J25 not connected to any
- J21 not connected to any
- SW4 is turned to ON, and the remaining SW1, SW2, and SW3 must not be in the ON position.
Important
-
The SIM7080G-ESP32S3 version does not expose the battery external pin. The battery external function of SimShield cannot be used. The positive pole of the 18650 battery holder needs to be welded to the left pin.In the picture, +BAT points to the welding direction of the positive pole of the battery.
-
The SIM7080G-ESP32S3 version has an onboard 18650 battery holder that conflicts with SimShield. The battery holder must be removed before installation
-
The SIM7080G PMU version is not fully compatible with other versions in terms of PinHeader. Therefore, when connecting to the SIMShield, the
DC5andVSYSpins must not be connected to theSIM Shield; that is, theDC5andVSYSpins must be empty. -
The SIM7080G PMU version does not expose a 5V input pin. The included 2.00mm wire needs to be soldered to the position shown in the diagram below on the motherboard in order for the board to accept a 5V power input.
| SIM7080G ESP32S3 | GPIO |
|---|---|
| SIMSHIELD_MOSI | 11 |
| SIMSHIELD_MISO | 13 |
| SIMSHIELD_SCK | 12 |
| SIMSHIELD_SD_CS | 21 |
| SIMSHIELD_RADIO_BUSY | 48 |
| SIMSHIELD_RADIO_CS | 45 |
| SIMSHIELD_RADIO_IRQ | 8 |
| SIMSHIELD_RADIO_RST | 47 |
| SIMSHIELD_RS_RX | 2 |
| SIMSHIELD_RS_TX | 1 |
| SIMSHIELD_SDA | 44 |
| SIMSHIELD_SCL | 43 |
- J25 short IO -> LP2
- J21 short RP1 -> 5V
- SW1 is turned to ON, and the remaining SW2, SW3, and SW4 must not be in the ON position.
| SIM7000G/A7670X/SIM7670G/SIM7080G Standard Series | GPIO |
|---|---|
| SIMSHIELD_MOSI | 11 |
| SIMSHIELD_MISO | 13 |
| SIMSHIELD_SCK | 12 |
| SIMSHIELD_SD_CS | 37 |
| SIMSHIELD_RADIO_BUSY | 15 |
| SIMSHIELD_RADIO_CS | 38 |
| SIMSHIELD_RADIO_IRQ | 14 |
| SIMSHIELD_RADIO_RST | 39 |
| SIMSHIELD_RS_RX | 40 |
| SIMSHIELD_RS_TX | 41 |
| SIMSHIELD_SDA | 3 |
| SIMSHIELD_SCL | 2 |
- Standard Series uses the same GPIO regardless of modem model
- Follow the method shown in the figure below to short-circuit the jumper cap to route the external battery connector to the mainboard battery interface and skip the current detection.
- The vertical jumper cap in the figure below routes the battery current to INA3221 channel 2, and the battery charging and discharging current can be monitored by reading the INA3221 sensor. At this time, do not connect anything to the crimp terminal interface.
- If the jumper cap is not connected, the crimp terminal interface current is monitored
- This port is for external power supply and has no other functions.
- You can also use the same JST 2.0mm cable to connect directly to the mainboard solar port for charging, but make sure the J21 jumper cap is unconnected.
- Using the JST 2.0 cable for charging reduces the voltage drop across the SimShield diode. However, using J21 to provide power will increase the DC power supply input voltage drop. If solar power is not available, connecting the JST 2.0 port to the solar input port is a better option.
- SimShield remaps the SPI interface. After using SimShield, do not insert the SD card into the motherboard. Instead, insert the SD card into SimShield.
- RS485 uses hardware automatic sending and receiving control, and it is recommended to use a communication baud rate below 115200
- 0.96-inch OLED display
- The I2C interface is suitable for OLED screens connected to conventional interfaces. Please note that the OLED interface has two line sequences. Please make sure that the line sequence is correct. Please refer to this link for the OLED interface
- SPI interface exposes the SPI bus interface of SD card/Radio
- If the jumper of current detection channel 2 is selected as the battery detection channel, the external wiring terminal is unavailable.
- Channel 3 and channel 1 are free to use. The IN+ of the terminal is the direction of current inflow, G is the GND of the load, and IN- is the direction of current outflow from the load.
| Name | Details |
|---|---|
| INPUT:7~36V | DC input, range 7 ~ 36 V |
| OUTPUT:5V | Only when DC is input will 5V voltage be output |
| VBAT:+4.2V- | Battery input interface, maximum 4.2V |
| IN+ G IN- CH2 | Current detection channel 2 |
| IN+ G IN- CH3 | Current detection channel 3 |
| IN+ G IN- CH1 | Current detection channel 1 |
- The battery input interface is connected in parallel with the onboard 18650. If an external battery is connected, do not install the battery on the 18650 socket.
- Current detection channel 1 (this channel is unavailable if a battery is connected via a jumper cap)