KISSLoRa gadget with a slim fitting case

This is the KISSLoRa gadget. This was the gadget of the Electronics & Applications 2017. Here I present the second iteration of the 3D printed case. I tried to find the exact positions of the connectors. I think I succeeded this time.

The requirements for the casing are (Please feel free to add yours on the comment section on the bottom of the page, I just enabled comments again, they were offline):

• Both SPI and I2C connectors should be accessible, but there should be a cap top close the holes separately.
• Battery, power and microUSB should be accessible from outside.
• All the leds should be visible, I might use light guides for them.
• The button and on/off switch should be controllable.
• There should be a ventilation hole for the temp, pressure and humidity sensor.
• The application switch should be turnable, and the numbers should be visible.
• There should be a marker where to drill a hole when you want to add a 1/4 wave antenna.

I am still puzzling on the fact to keep the battery inside or outside the housing, I will try to keep both options open.

Here is the first iteration of the 3D printed case. I did not get the dimensions exactly right and the device did not fit 😉 Can you find the slight mistake I made . ..

Use the #KISSLORA when posting on social media! First some handy links:

• Github repository with all kinds of information.
• The schematic of the thingy.
• TheThingsNetwork user forum.
• Help to build the community.

On board you will find:

• U5: Microchip RN2483 Low-Power Long Range LoRa™ Technology Transceiver Module.
• U1: ATmega32u4 8-bit Microcontroller with 32K bytes of ISP Flash and USB Controller.
• U2: FXLS8471Q 3-Axis Linear Accelerometer.
• U3: APDS-9007 Ambient Light Photo Sensor with Logarithmic Current Output.
• U4: SI7021-A20 I2C Humidity and Temperature sensor.

There are 7 connectors on the board.

• J1: JTAG connector, which can be used to program and debug the controller.
• J2: I2C connector. With the cable you have received a connector (J7, 3-pins term block plug) which fits in there.
• J3: SPI connector.
• J4: Power jack, which accepts 5 volts. I will try to find out what the minimum and maximum rating is. It draws less than 150 mA.
• J5: Battery connector. Vmax: 4.25V Vnom: 3.7V Low Batt @ ≤3.1 V C 350 mAh I_charge: 100mA
• J6: MicroUSB connector, also for power and for communication with your laptop.
• J8: LoRa programming header, which only has holes, no pins connected (yet).

The board has a couple of LEDs. The red LED (D6) is lighting up when the battery is charging. When there is no battery connected it stays off. The green LED (D5) is only on when the board is powered (Power Good) via J4 and/or J5 AND the power switch is on. There is also a blue LED (D2) and an RGB LED (D3) on the board. The RGB is user programmable.

That is the theory, it took a loooooong time for the red LED to switch off. Charging the battery just took longer than I expected. More power measurements will follow to benchmark how long it takes to charge/drain the battery completely.

The power supply is done over the microUSB connector or on the power jack connector which accepts 5 volts. On GitHub you can find the repository with all the information to start using the KISS LoRa module.

On the board is also an application selection (rotary) switch (U5). Here are the possible positions with their behavior when using the standard firmware:

• 0: Sensor-to-cloud (should be default).
• 1: Sensor-to-cloud with LoRa-packet countdown (this position was selected when I got it).
• 2: LoRa DownLink Check.
• 3: Gravity Sensor.
• 4: Acceleration Sensor.
• 5: Dice Roller.
• 6: Mood Light.
• 7: Night Light.
• 8: Temperature Range Checker.
• 9: Humidity Sensor.

At the E&A 2017 I also received a particulate matter (PM2.5 and PM10) meter from the company Intemo. This device can be connected with J2 where it can communicate I2C with. More on that later.

When connected to a Windows laptop, the Device Manager is showing the current information:
Device Description:
USB Serial Device (COM4)

Hardware Ids:
USB\VID_1B4F&PID_9204&REV_0100&MI_00
USB\VID_1B4F&PID_9204&MI_00

Bus reported device description:
SparkFun Pro Micro

Here is a video of the production of the gadget. Production of the gadget was (partly) done at the Electronics & Applications 2017

A big thumbs up for all the main sponsors who made this gadget possible:

• Gepro Electronics B.V. for the hardware and software development.
• AssemblyPartner for the production of the gadget.
• Alcom Electronics B.V. together with Microchip for supplying the major components (LoRa, uC, charger, sensor).
• Eurocircuits for developing and producing the PCB.
• The Things Network for the open network to connect to.
• Würth Elektronik for all other components on the board.