# SIM808 GSM/GPS module: specs and pinout

> Module built around the SIMCom SIM808 chip: quad-band GSM/GPRS, a GPS receiver and Bluetooth, controlled by AT commands over a serial port.

[HTML version](https://soldr.ai/docs/components/sim808)

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Module built around the SIMCom SIM808 chip: quad-band GSM/GPRS, a GPS receiver and Bluetooth, controlled by AT commands over a serial port.

Every value cites its sourceChip-level pinout

[Buy on Compoden](https://compoden.com/products/sim808-bluetooth-compatible-gsm-gprs-gps-module)

## Specs

| Spec | Value | Source |
|---|---|---|
| Chip supply (VBAT) | 3.4 V to 4.4 V (typical 4.0 V) | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 1 key features, p.10; Table 39, section 6.2 |
| Peak supply current | Up to about 2 A in transmit bursts; supply must give sufficient current up to 2 A and VBAT must not drop below 3.0 V | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), section 4.1 Power supply, p.20 |
| GSM/GPRS bands | Quad-band: GSM 850, EGSM 900, DCS 1800, PCS 1900; GPRS multi-slot class 12 default | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 1, p.10-11 |
| GPRS data rate | 85.6 kbps maximum uplink and downlink | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 1, p.11 |
| GPS engine | 22 tracking / 66 acquisition channels, NMEA protocol, update rate 1 Hz (5 Hz max) | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 2 GPS engine performance, p.12 |
| GPS horizontal accuracy | Less than 2.5 m autonomous (50% 24 h static, -130 dBm) | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 2, p.12 |
| GPS power consumption | 42 mA acquisition, 24 mA continuous tracking | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 2, p.12 |
| Bluetooth | Bluetooth 3.0 + EDR, controlled by AT commands | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), section 4.9, p.39 |
| Serial port logic levels | VIH 2.5-2.8 V, VOH 2.7-2.8 V (about 2.8 V domain); autobauding 1200-115200 bps | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 11 p.31; section 4.6.1 |
| Operating temperature | -40 C to +85 C (storage -45 C to +90 C) | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 1 p.11; Table 39 section 6.2 |

## Power

| | Value | Source |
|---|---|---|
| Supply | Chip VBAT 3.4-4.4 V; the module board's own input is not covered by the maker document | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 1; section 4.1 |
| Current | Peaks up to about 2 A in transmit bursts (chip) | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 1; section 4.1 |

## Chip pins
These are the pins of the chip on the module, from the chip datasheet. The module's own header may label or expose them differently.

The module board (regulator, level shifting, antenna connectors, supply input, header order) is not covered by an official document; the rows are the chip's serial and USB pins from the SIMCom hardware design.

| Pin | Function | Voltage | Notes | Source |
|---|---|---|---|---|
| DTR (chip pin 9) | Data terminal ready | ~2.8 V | Chip pin, not the module header | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 10, p.31 |
| RI (chip pin 10) | Ring indicator | ~2.8 V | Chip pin, not the module header | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 10, p.31 |
| DCD (chip pin 11) | Data carrier detect | ~2.8 V | Chip pin, not the module header | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 10, p.31 |
| CTS (chip pin 12) | Clear to send | ~2.8 V | Hardware flow control is off by default | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 10, p.31 |
| RTS (chip pin 13) | Request to send | ~2.8 V | Hardware flow control is off by default | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 10, p.31 |
| TXD (chip pin 14) | Transmit data | ~2.8 V | | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 10, p.31 |
| RXD (chip pin 15) | Receive data | ~2.8 V | | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 10, p.31 |
| VBUS (chip pin 25) | USB power supply | | | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 10, p.31 |
| USB_DP (chip pin 26) | USB data plus | | | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 10, p.31 |
| USB_DM (chip pin 27) | USB data minus | | | source SIMCom SIM808 Hardware Design V1.00 (2014-03-27), Table 10, p.31 |

## Build with it
Project ideas for the SIM808 GSM/GPS module. Each link opens Soldr with the prompt filled in; Soldr assigns the pins, checks power and shows how to wire every part.

- [GPS bike tracker with SMS location](https://app.soldr.ai/?prompt=I%20want%20to%20build%20a%20GPS%20tracker%20for%20my%20own%20bike%20that%20sends%20its%20location%20by%20SMS%2C%20with%20an%20ESP32%20and%20a%20SIM808%20module): Track your own property only; never track a person without their consent. Power the SIM808 from its own protected single 18650 cell: the cell goes through the 1S 3.7 V 3 A protection board, whose 3 A rating is above the 2 A transmit burst the SIMCom document requires (section 4.1); check the cell's own discharge rating covers 2 A, and that the module board's supply input accepts the cell voltage (3.4-4.4 V at the chip). Run the ESP32 from its own USB supply, not from this cell, and join the grounds. Check the module's serial level before wiring it to the ESP32.
- [Remote temperature reporter](https://app.soldr.ai/?prompt=I%20want%20to%20build%20a%20remote%20temperature%20reporter%20that%20sends%20readings%20by%20SMS%2C%20with%20an%20ESP32%2C%20a%20DS18B20%20probe%20and%20a%20SIM808%20module): A place with no Wi-Fi can still report by SMS. The module's chip works down to -40 C, but the battery does not; keep the pack indoors. Learning project. Power the SIM808 from its own protected single 18650 cell: the cell goes through the 1S 3.7 V 3 A protection board, whose 3 A rating is above the 2 A transmit burst the SIMCom document requires (section 4.1); check the cell's own discharge rating covers 2 A, and that the module board's supply input accepts the cell voltage (3.4-4.4 V at the chip). Run the ESP32 from its own USB supply, not from this cell, and join the grounds.
- [GPS position display](https://app.soldr.ai/?prompt=I%20want%20to%20build%20a%20handheld%20GPS%20position%20display%20with%20an%20ESP32%2C%20a%20SIM808%20module%20and%20an%20OLED): The chip's GPS engine outputs NMEA over the serial port; the ESP32 parses it and shows latitude and longitude on the I2C display. Learning project. Power the SIM808 from its own protected single 18650 cell: the cell goes through the 1S 3.7 V 3 A protection board, whose 3 A rating is above the 2 A transmit burst the SIMCom document requires (section 4.1); check the cell's own discharge rating covers 2 A, and that the module board's supply input accepts the cell voltage (3.4-4.4 V at the chip). Run the ESP32 from its own USB supply, not from this cell, and join the grounds.

## Common mistakes

- Under-powering it: transmit bursts draw peaks up to about 2 A and the chip may shut down if VBAT falls below 3.0 V (source: [link](https://cdn-shop.adafruit.com/datasheets/SIM808_Hardware+Design_V1.00.pdf), section 4.1 Power Supply, p.20)
- Putting a 3.3 V or 5 V host signal on the serial pins without checking: the chip's serial pins are in a 2.8 V domain (VIH 2.5-2.8 V); check what level shifting the board has (source: [link](https://cdn-shop.adafruit.com/datasheets/SIM808_Hardware+Design_V1.00.pdf), Table 11)
- Not syncing the baud rate: autobauding is the default, and the host must send AT until it receives OK (source: [link](https://cdn-shop.adafruit.com/datasheets/SIM808_Hardware+Design_V1.00.pdf), section 4.6.1)

## Not covered by the official source

- The module board is not documented by SIMCom; its supply input, logic level and header labels are not given.
- Check that 2G service is available where you use it before relying on SMS or GPRS.
- The 3 A rating of the protection board and the discharge rating of the 18650 cell are not from a maker document; check the markings on the parts you use.

## Sources

- [link](https://cdn-shop.adafruit.com/datasheets/SIM808_Hardware+Design_V1.00.pdf) (SIMCom SIM808 Hardware Design V1.00, 2014-03-27)