This version (12 Oct 2023 09:28) was approved by Joyce Velasco, erbe reyta.The Previously approved version (12 Oct 2023 09:21) is available.
Table of Contents
MAX32670 and SX1261 Base Board
This LoRa Reference Design Base Board consists of the MAX32670 high-reliability, ultralow power microcontroller based on Arm Cortex-M4 processor, and the LoRa RF transceiver module targeting SX1261.
In order to use this base board, all hardware settings such as the hardware peripheral connections, jumpers and UART switch configurations, power configurations, connectivity options, and the USB connectors and programming connections are provided in this page. Links to the schematics and the layout files are also available below.
Peripheral Connectors
The following standard connectors are provided on the base board for customer to use with external add on modules:
| Connector Name | Function |
|---|---|
| DC Power Connector Header | Input range from +4 V to +6 V DC supply voltage |
| Battery Holder | Battery holder for CR123A |
| Cortex SWD Header | Used for flash programming and debug interface; also, provides a virtual serial port connection to MAX32670 microcontroller |
| PMOD_SPI | 12-pin SPI PMOD connector |
| PMOD_I2C | 8-pin I2C PMOD connector |
| ESP32 Connector | ESP32 Devkit V1 connector |
| Arduino Connectors | Arduino Uno Rev3 compatible connectors |
MAX32670 MCU Pin Map
The pin map for the MAX32670 is described in the table and its schematic diagram below.
ESP32 Connector Pin Map
All connector pinouts for the Development Board are described in the table and its schematic diagram below.
Arduino Connector Pin Map
PMOD Connector Pin Map
Wireless Connectivity Options
This board has two wireless connectivity options available to use for Internet of Things (IoT) applications:
- On-board Chip Antenna
- External Antenna connected through SMA connector
These options can be configured by populating C63 with 39 pF for the external antenna or R156 with 0 Ω for on-board RF chip antenna with the center frequency tuned at 915 MHz.
LoRa Chipset
The MAX32670 has a dedicated LoRa chipset on board from Semtech (SX1261). This chipset comes complete with the full LoRaWan software protocol and stack, allowing the MAX32670 to operate, occupying a small portion of its memory space for the LoRaWan protocol.
The MAX32670 communicates to the SX1261 using the SPI bus, so the users will need to send LoRa commands and data over SPI bus. Library functions calls have been specifically designed to be used with the MAX32670 and SX1261 using SPI bus.
The pins that connect the MAX32670 and the SX1261 are as follows:
Input Power Source Options
There are two (2) ways of powering the eval board, and user may use any combination of power sources.
- Terminal Block - can be used when an external supply is connected to the Terminal block connector P11.
- Battery Powered - can be used when batteries are connected to BT1 connector on the back of the board.
Each of the different power modes, provides a different level of control and flexibility. You can find a matrix table of the different power modes and their general function here:
| Power Source | Voltage Rails Provided | Peripherals Powered | Function |
|---|---|---|---|
| Terminal Block (P11) | 3 V to 6 V | - MAX32670 - SPI and I2C PMODs - ESP32 connectors - Arduino connectors - LoRa chip | able to supply ALL voltages any peripheral might need |
| Battery Power (BT1) | 3 V and 6 V | - MAX32670 - SPI and I2C PMODs - ESP32 connectors - Arduino connectors - LoRa chip | able to supply ALL voltages any peripheral might need |
Push Buttons
The base board provides three buttons for use: S1, S2, and S3.
| Button | Function |
|---|---|
| S1 | can be used to record timestamps and/or assert an interrupt on a falling/rising edge of the DIN signal on MAX31334, an ultralow power RTC with integrated power switch. Initially short to ground via 0ohm resistor(R4). See the MAX31334 page for more details. |
| S2 | provides a hardware RESET to MAX32670 microcontroller. |
| S3 | provides a hardware RESET to MAX77675, buck/buck and boost/boost regulators. The manual reset function is useful for forcing a power-down in case communication with the processor fails. |
LED Indicators
The base board has five LEDs: DS1, DS2DS3, DS4, and DS5.
| Button | Function |
|---|---|
| DS1 | used as a LED indicator to one of the GPIO of the MAX32670, P0.28. |
| DS2 | used as a LED indicator to one of the GPIO of the MAX32670, P0.29. |
| DS3 | used as a LED indicator for the voltage output from the power supply. |
| DS4 | used as a LED indicator for the voltage output from the MAX31334. |
| DS5 | used as a LED indicator for the 3.3V voltage output from the MAX3130. |
Programming Connectors
This board uses SWD Interface and uses the MAX32625PICO board for programming the on-board MCUs. See the MAX32625PICO page for more details.
- P1 - SWD Interface used to program the MAX32670
The connector used are based off the 10-pin ARM Cortex standard pinout (0.05“ pin spacing). That pinout is common to both JTAG and SWD debug modes and is depicted in the following image.
The debugger board will need to be plugged in via the USB port in order to program any board.
In order to program the MAX32670 node board, that board must be powered by (1) CR123A battery or by an external power supply through P11. Otherwise, there will be no connection between the two boards.
Schematics, PCB Layout, Bill of Materials
Design and Integration Files
Navigation - ADI LoRa
Prev.: HardwareUp: MAX32670 and SX1261 Base Board
resources/eval/user-guides/lora-reference-design/hardware/max32670-sx1261.txt · Last modified: 12 Oct 2023 09:28 by Joyce Velasco