Mesh networking for sensor grids

May 8, 2017May 6, 2017 fustiniiot, mesh, microcontroller, MQTT, Networking, RF, sensor, wirelessLeave a comment

Mesh networking board by Daniel on Hackaday.io:

Low-power mesh networking for small sensor grids

Tiny MQTT-interoperable broadcast mesh networking with simple radios

This project is a low-resource mesh networking stack and mote with battery-powered routers based on state synchronization. The target is for the stack to use less than 2kb SRAM. Nodes use low power listening and an adaptive gossip protocol to synchronize key/values pairs with each other without relying on explicit routing or per-node addressing.

For example, a light might transmit (/lamp, {“state”:”on”}) to the mesh. Write (/lamp, {“state”:”off”}) to the mesh, and the lamp application will notice. The powerful but simple state synchronization primitive allows you to update the state of the mesh to update the world, and update the state of the world to express the same on the mesh. Trivially bridged to a private MQTT server and managed with off-the-shelf MQTT applications.

The design files and source code are available on Bitbucket:

dholth/mesh

SAMD21G18A Sensor Board with Color OLED

April 29, 2017April 24, 2017 fustiniatmel, OLED, SAMD21, sensorLeave a comment

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SAMD21G18A Sensor Board with Color LED by Mike Rankin. The design files are source code available on GitHub:

SAMD21G18A_Sensor_Board_with_Color_Oled

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Here’s a video of the board:

Hall Sensor Preamp

March 19, 2017March 8, 2017 fustiniADC, sensorLeave a comment

Piotr Zapart designed this board to overcome range issues when using traditional 300 degree potentiometers or Hall sensors as rotational angle to voltage converters:

HALL Preamp/Analog axis calibrator

The idea was to create a device that will perform an axis calibration, usually done in digital domain, but before sampling the signal in the ADC, still in analog domain, using it’s advantageous infinite resolution

the main function of this device is to:

Buffer the analog output signal coming from a potentiometer or another rotary angle to voltage converter like ie. Hall sensors.

Filter out the high band noise and limit the bandwidth to an usable range only, protect the input against voltage spikes.

Match the output voltage range of the source (pot/hall sensor) with the input range of the ADC, thus making the most of the available ADC resolution.

Linearize the hall sensor output signal response by amplyfing it’s most linear region to the full scale ADC input range.

The board is shared on OSH Park: