Project mass airflow sensor (hardware)

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+hardware/proposals/mechanical/*.lck

hardware/proposals/MassAirflowSensor.md

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+---
+path: "/projects/hardware/MassAirflowSensor"
+title: "MassAirflowSensor"
+---
+
+# The above values are used for the website, please make sure to fill them out.
+
+# PLEASE COPY THE DOCUMENT AND START YOUR PROPOSAL ON YOUR COPY 
+| | |
+|-|-|
+| Proposal Stage |      |
+| Tags           |      |
+| Created Date   |      |
+| Lead           |      |
+| Slack Channel  |      |
+
+## 📃 Idea in brief: Question to be resolved and why
+Mass airflow sensors seem to be a possible component that is required for a ventilator.
+
+Proposing to create an open-source version to be available if and when it is needed.
+
+
+### 💥 Problem
+Mass airflow sensors need to measure the amount of air pass thru the device. In breathing systems, accuracy and response time of the data is required. 
+
+### 👨‍🔬Hypothesis
+Venturi style flow sensors are well understood and easy to fabricate. 
+
+Need the following for a complete design:
+Mechanical housing that interfaces with breathing hoses on each end with venturi design optimized for airflows anticipated
+Temperature compensated pressure sensors placement in venturi
+PCB design for pressure sensors, signal circuitry, heaters, temperature sensors, and i2c 
+
+### 🤔 Assumptions
+Mechanical:
+Air fittings to comply with ISO5356-1:2004
+Flow range: ±250 slm (bidirectional) 
+Minimum pressure drop
+
+
+Electrical:
+Logic supply voltage is 3.3VDC±5% or 5VDC±5%
+Temperature compensation needed for pressure sensors with closed loop heater control
+I2C should support 3.3V logic or 5V logic
+
+Interface:
+I2C support is a must-have
+CANBUS as a nice-to-have
+Very fast update time (0.5 ms)
+Calibratible 
+
+
+## 💻Implementation Suggestion
+
+### V1
+Reverse engineer existing devices
+Look at pressure sensors required and locations in venturi. 
+
+### What it is
+Sensor using all open-source and OTS parts, with embedded microcontroller running open source firmware
+
+### What it is not
+This is sensor only, not a control valve.
+
+### Design
+
+
+### Data/Experiments
+
+
+V2 (..repeat the process)
+
+## 💪 Impact of Potential Solution
+
+## 🙌 Criteria for Success
+(Main KPIs, metrics to evaluate and results to achieve)
+
+## 😅 Known Issues
+Accurate calibration when built needs to be determined. No point in creating a innaccurate device. Need a clever way to field calibrate.
+
+## ✅ "I've read this" section
+Add in the table below the people you definitely want their eyes on this proposal. Sometimes there are no comments to be made but it's good to know people have read the proposal
+
+| Name | Status |
+|-|-|
+|  |  Read/Not Read    |