#Reach This document outlines the progress on the Gossip-over-BLE implementation.

##Flashing the softdevice First grab the s110 softdevice folder and put it in the top level directory of this repo. Use a JLink-speaking programmer and connect one of the devboards. Run make flash-softdevice to get the softdevice onto the nrf51822.

##Building the project

###Requirements

Install JLink GDB server. scroll down to "J-Link software & documentation pack for MAC") https://www.segger.com/jlink-software.html

Install Nordic packages. Try the following handy script.

mkdir -p nRF51_SDK_7.1.0
curl http://developer.nordicsemi.com/nRF51_SDK/nRF51_SDK_7.1.0_372d17a.zip | tar xvf - -C nRF51_SDK_7.1.0

mkdir -p s110_nrf51822_7.1.0
curl http://www.nordicsemi.com/eng/nordic/download_resource/30082/12/50064729 | tar xvf - -C s110_nrf51822_7.1.0

Install gcc-arm. brew tap tessel/tools and brew install gcc-arm. (If your gcc-arm location is different, set make GNU_INSTALL_ROOT=/usr/local/wherever.)

###Running code

Use make to compile and link the application binary.

Use make flash-softdevice to load the softdevice on the nrf51822.

Use make flash to load the application on the nrf51822 after the softdevice.

##Gossip BLE Profile A preliminary draft of the GATT Profile for communicating with Gossip over BLE is in the profiles.json file in this repo. It currently defines 3 proprietary services: "Gossip IO Protocol Service", "Reach Configuration Protocol Service", and "Reach OTA Update Protocol Service". The former has 2 characteristics used separately for upstream and downstream message passing, mimicking a duplex stream. The latter two services are in place as an example for UUID assignment conventions should more services be deemed necessary.

##nrf51822 Client The nrf51822 client code is mostly contained in /src/main.c, and outlines all of the GAP (connection) and GATT (profile) set up.

##Tessel Client The Tessel client can be found in the client.js file. The majority of this code is dedicated to establishing a connection with a host over BLE. This file also contains a Gossip object used for parsing incoming packets, executing the appropriate function, and sending the appropriate response. Current implementation is a port of the Rust parser to JavaScript, and only has the SPI functionality.

##Host The current host implementation uses noble to interface with the BLE adapter on a computer, source located in the host.js file. Again, most of this file is dedicated to establishing a BLE connection with a Reach client. Lacks most Gossip logic.

##Road map Priorities

1. Get firmware build & deploy set up for nrf51822 w/open source tools

• Port current client code to C using nrf51822 SDK
  • Connection logic
  • Gossip logic
  • SPI
  • UART
  • I2C
  • GPIO
• Expand host capabilities to include Gossip logic
• Neatly package demo closely resembling final product

##Running Current Code npm install to install necessary dependencies.

tessel run client.js to run the client on a Tessel. Must have BLE module on port A.

node host.js to run the host. Must be run on a computer with BLE hardware.