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We are looking for an experienced Embedded developer to create energy-efficient firmware for a wearable device (form factor: chest strap) for monitoring psychophysiological state. The circuit design is complete, and development will be based on a development kit with subsequent transfer to a custom board.Stack and hardware base:MCU: Nordic Semiconductor nRF52840 or nRF5340.Development environment: nRF Connect SDK / Zephyr RTOS (strictly C/C++).Peripherals:Optical pulse sensor (PPG) — operates via I2C.6-axis inertial sensor (IMU accelerometer + gyroscope) — operates via SPI.Haptic motor driver (LRA 1030) — controlled via PWM.External SPI Flash memory for cyclic logging.Work scope by stagesStage 1: Bring-up, peripheral drivers, and BLE telemetryGoal: Bring the hardware to life, set up stable data collection, and transmit it to a smartphone/PC.Configure I2C and SPI buses using DMA (Direct Memory Access) to offload the processor.Write/integrate drivers for PPG and IMU (configure polling frequency, sensor FIFO buffers).Deploy a custom BLE profile (GATT service) for real-time transmission of raw data from sensors.Basic initialization of PWM for controlling the haptic LRA motor (launch test vibration patterns).Stage 2: Algorithmic layer (DSP and multi-level feedback logic)Goal: Implement mathematical signal processing directly on the chip (Edge Computing) and device reaction logic.Implement algorithms for filtering motion artifacts: clean the PPG signal using accelerometer data (IMU).Extract R-R intervals (HRV) from the cleaned PPG signal.Implement 4-level system stability logic:Drift Level: Track gradual changes in HRV and breathing.Prediction Level: Calculate a mathematical trend for deterioration.Micro-correction Level: Generate barely noticeable haptic patterns on the LRA motor when a target data pattern is detected.Hardware Reset Level: Implement safety logic (high-intensity haptic pulse at critical metrics).Stage 3: Energy saving, logging, and fault toleranceGoal: Prepare the device for autonomous operation from a miniature battery and ensure "24/7" stability.Deep optimization of energy consumption. Put the MCU into sleep mode (System ON/OFF) between measurement cycles. The processor should wake up only on interrupts from sensor FIFO buffers or a timer.Write a fault-tolerant file system in external SPI Flash (e.g., LittleFS) for autonomous cyclic log saving.Configure a hardware watchdog timer to prevent firmware hangs.Requirements for the performer:Experience in commercial development for Nordic chips (nRF52/nRF53) of at least 3 years.Proficient in Zephyr RTOS and debugging tools (Segger Embedded Studio / VS Code, J-Link).Understanding of digital signal filtering principles (DSP) and low-power design.Having your own debugging kit (nRF52840-DK or similar) for starting work is welcome.Work format:Milestone payments with results documented on GitHub. Please indicate your hourly rate or approximate cost and timeline estimates for each of the three stages.

Project Description We are looking for an experienced developer or a small team to create a modern online store for an optical salon. The goal is not just to update the design, but to create an effective online sales tool that will become the main sales channel for the company in the future. The current website is already operational and has an SEO history, so it is important to maintain Google rankings as much as possible during the transition to the new site. We will base the UX and functionality on modern global optical online stores (for example, Warby Parker), but the solutions must be adapted to the Ukrainian market.Required Functionality WordPress + WooCommerce modern responsive design product catalog with filters Mega Menu selection of frames and lenses glasses order builder ability to upload a prescription online appointment for vision check online payment integration with Nova Poshta simple administrative panel product import SEO-friendly structure possibility of further integration of an AI consultantImportant A specialist is needed who has experience in creating online stores, understands UX, SEO, conversion, and can offer their own solutions for improving the project. A detailed technical task will be provided after the preliminary selection of candidates.Please include in your response Links to 3–5 similar implemented online stores. Your experience with WooCommerce. How you plan to maintain SEO during the site transfer. What improvements you recommend to increase conversion. Estimated cost of the project. Estimated completion time.Specialization ✅ Website creation ✅ Online stores and e-commerce ✅ WordPress ✅ WooCommerce ✅ PHP

It is necessary to develop a modern online store for electric, gasoline, and battery tools with a separate B2B platform for partners, dealers, and dropshippers. At this stage, I would like to receive a preliminary estimate of the cost, development timelines, and technology recommendations. (because I have a website on the Horoshop platform)Main Site The following should be provided: a product catalog with categories, brands, filters, and search; product pages with specifications, photos, descriptions, prices, and availability; cart and order checkout; customer personal account; adaptive version for phone, tablet, and computer; SEO settings; the ability to independently add and edit products, categories, pages, and banners; integrations with payment systems, delivery services, CRM, or accounting systems; import and automatic updating of products, prices, and stock.B2B Platform After authorization, the partner should have access to a separate account where they can: see individual or wholesale prices; view current product stock; create and track orders; view order history; see order statuses; view their balance, debts, payments, and settlements; upload invoices, waybills, and other documents; submit requests for returns, warranties, or service; receive notifications about new products, promotions, and price changes. It is preferable to provide different types of partners with varying prices, discounts, credit limits, and working conditions.Administrative Part The administrator should be able to: manage products, prices, and stock; create partners and assign them individual conditions; set personal discounts and limits; view all orders, payments, and debts; generate documents; view sales statistics; manage service, return, and warranty requests; send messages to individual partners or all users of the B2B platform; distribute access rights among employees.Important Requirements The system must be fast, secure, user-friendly, and suitable for further expansion. It is important that most information can be changed through the admin panel without the intervention of a programmer. In your response, please indicate: the estimated cost of development; approximate timelines; recommended technology or CMS; what is included in the cost; which integrations can be implemented; whether you provide further technical support; examples of similar online stores or B2B systems that you have developed. I am considering both a complete development from scratch and implementation on a ready-made CMS with further refinement for the necessary functionality.

Looking for an experienced developer OpenCart / ocStore who can transfer the existing online store to a modern version of the system and make several small improvements. First, an audit of the site is necessary! https://bigbears.com.ua/ Initial Data Active site on ocStore 2.3.0.2.3 The store is operational and accepting orders. It is necessary to maintain the store's functionality. The domain and hosting remain the same.Main Task The site needs to be transferred to the current stable version of OpenCart / ocStore. During the transfer, it is necessary to preserve: all products; categories; manufacturers; photos; attributes; options; SEO URLs; customers; order history; store settings (if possible).Additionally After the transfer, some small improvements need to be made. Currently, they are minor but may be added during the work process. For example: fixing minor bugs; small changes in the admin panel; small changes on the site; module configuration; fixing the display of individual elements.Requirements Experience specifically with OpenCart / ocStore. Preferably, completed projects. Work through a test copy of the site. Make a full backup before starting. Provide a working site without data loss after completion. It is preferable that after the project is completed, the contractor can make small improvements if necessary.What Will Be Provided The contractor will be provided with: FTP access; database access; admin panel access; hosting access if necessary.Please Indicate in Your Response Experience working with OpenCart / ocStore. Which versions you have transferred. Examples of completed projects. Completion time. Cost of work. What difficulties may arise during the transfer.

Вітаю! Шановні фрілансери. Необхідно налаштувати передачу товарів з сайту на OpenCart на сайт Пром. Зі збереженням знижки на кількість. При цьому щоб мати можливість зробити націнку на товари, які передаються. Дякую. Прошу звертатися тільки тим, хто не "зникає". Працюю виключно через Сейф