Particle Projects

June 2020

Particle Boron Data Publisher

Based on the Particle Boron IoT device, this custom data publisher features the following:

Cellular LTE communication
Powered by 12VDC (sleeps when vehicle power is lost)
Battery backup
GPS position, speed, angle, altitude, UTC datetime
Triple Axis Accelerometer (0 to 16g)
Ambient Temperature
5 analog single-ended inputs (A0 to A4) with 0.806 mV resolution.
2 digital inputs
OLED Display for status and live view of data

You can read the battery voltage using: float voltage = analogRead(BATT) * 0.0011224;

Solution to changing analog reference

Nordic SAADC Driver for advanced analog input sampling

Configure Xenon/Argon/Boron for differential analog input

Device OS code for reading the ADC

FeatherWing Resources

The pinout diagram below is organized to lay over the physical footprint of the devices when they are oriented with the USB connector at the top, and looking from the top of the devices (header pins pointing downward).

Pinout Comparison
Boron	DataLogger	\|	Argon Boron	DataLogger
RST	RST	\|	---	---
3V3	20 mA	\|	---	---
D20	ARf	\|	---	---
GND	GND	\|	---	---
A0 D19	AI A0	\|	Li+	Li+
A1 D18	AI A1	\|	EN	EN
A2 D17	AI A2	\|	Vusb	Vusb
A3 D16	AI A3	\|	D8	DO D8
A4 D15	AI A4	\|	D7 LED	DO D7 LED
A5 D14 SS		\|	D6	DI D6
D13 SCK	D13 SCK	\|	D5	DI D5
D12 MOSI	D12 MOSI	\|	D4 MISO	OLED btn A
D11 MISO	D11 MISO	\|	D3 SCL1 MOSI UART1_CTS	OLED btn B
D10 UART1 Tx	GPS Tx	\|	D2 SDA1 SCK UART1_RTS	OLED btn C
D9 UART1 Tx	GPS Rx	\|	D1 SCL	ACCEL OLED SCL
NC	NC	\|	D0 SDA	ACCEL OLED SDA

Color Key: SPI SPI1 I2C

NOTES: AI=analog input; DI=digital input; DO=digital output;

128x32 OLED uses I2C address 0x3C.

ADT7410 uses I2C address 0x48 by default.

ADXL343 uses I2C address 0x53 by default.

GPS & RTC

AF GPS FeatherWing

AF GPS FeatherWing tutorial

AF GPS library

The 12 mm coin cell (CR1220) provides backup power to the GPS for it's settings and for the RTC. The GPS sets the internal RTC when it gets a fix and then as long as the battery is installed, you can read the date/time from the GPS (as UTC) using the library, and you will get the correct time from the RTC (even without a proper GPS fix, the date/time will be correct). Position Accuracy: 1.8 meters. Velocity Accuracy: 0.1 meters/s (0.22 mph)

More AF FeatherWing products from Adafruit and from Particle

Do you need help developing or customizing a IoT product for your needs? Send me an email requesting a free one hour phone / web share consultation.

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