The u-blox SARA-R510M8S module is a secure cloud LTE Cat M1, LTE Cat NB2 solution based on u-blox's UBX-R5 cellular chipset. The SARA-R510M8S has an integrated u-blox M8 GNSS receiver chip and a separate GNSS antenna interface.
The SARA-R5's UART interface can be configured into one of five variants, providing connectivity over one or two UARTs. A separate USB port provides access to the SARA's trace log for diagnostic purposes. This breakout provides access to all three interfaces (UART1, UART2 and SARA Diag) via three separate USB-C connections. All eight 3.3V serial signals are available on a 0.1"-pitch breakout header.
- /Documentation - Datasheets etc.
- /Hardware - Eagle PCB, SCH and LBR design files. Full schematic in PDF format.
- LICENSE.md - License details
- SparkFun u-blox SARA-R5 Arduino Library - Arduino library for the SARA-R5 module.
- Hookup Guide - Hookup Guide for the LTE GNSS Breakout - SARA-R5.
The board comes pre-configured to support interface variants 0 and 1 (single UART, 8-wire connectivity). If you want to use variants 2-4 (dual UART), you will need to:
- Open the split pads adjacent to the DTR, DCD, RI and DSR breakout pins
- Close the solder split pads labelled TXD2, RXD2, RTS2 and CTS2
- Open the OUT split pad labelled DSR O RTS2 I and close the adjacent IN solder split pad
The serial signals on the breakout pins are all 3.3V. Level-shifting circuits connect them to the SARA's 1.8V UART pins.
The board can draw 5V power from any or all of the USB-C connectors. Optionally, you can provide power via the V EXT breakout pin: 3.7V Min; 6.0V Max.
If you want to use V EXT as an output, you can bypass the DVEXT protection diode by closing the V EXT Diode solder split pad.
The board's 3.3V current draw can be monitored via the MEAS header pins. Open the split pad linking these pins if required.
- NI - Network Indicator will be low when the SARA is on and the network is available.
- TP - GNSS Timing Pulse (PPS) pin will pulse low/high when configured by the +UTIME=1,1 command. Please see the AT Commands Manual for more details.
- SARA On - pull low for 5 seconds then release to turn the SARA off. Pull low briefly again to turn the SARA back on. You can tell if the SARA is powered by monitoring the VCCIO 1.8V pin.
- INT - by default this pin is connected to the SARA's bi-directional EXT INT pin. It can optionally be connected to GPIO3 by reconfiguring the SARA INT split pad.
- ~RESET - pull low and release to reset the SARA.
- SARA I2C - provides access to the SARA's I2C SDA and SCL pins.
- 3V3EN - pull this pin low to disable the 3.3V supply completely. Note: you may want to turn the SARA off using the SARA On pin first, so it disconnects from the network correctly.
NI, TP, SARA On, INT, ~RESET, SDA and SCL are all 3.3V. Level-shifting circuits connect them to the SARA's 1.8V I/O pins.
Important Note: VCCIO is 1.8V. You may need to connect it to an analog input to sense the voltage correctly.
Important Note: 3V3EN is pulled-up to VIN (5V) via a 100K resistor. We recommend using a switch or open-collector / open-drain output to pull 3V3EN low.
- Reset - pressing this switch will reset the SARA.
- SARA On - pressing and holding this switch for five seconds will turn the SARA off. Press briefly to turn the SARA back on again.
The board provides 3.3V power for an active GNSS antenna. By default the antenna power is enabled whenever the SARA is on. You can reconfigure the ANT GNSS PWR split pad to optionally control the antenna power via the SARA's GPIO2 pin.
The GPIO2 pin can be controlled using the +UGPIOC=23,0,1 command. Please see the AT Commands Manual for more details.
- GPS-18031 - Initial Release