11. Applications and Implications¶
Week Assignment¶
Final Project: Carbon Monoxide Monitoring System (COMS)
What will it do?¶
Every year in Jordan tens pf people found dead because of Carbon Monoxide Poisoning (COP). For many reasons people will continue using conventional heating system indoor, putting a lot in risk of death or serious health conditions. The Carbon Monoxide Monitoring System (COMS) will measure Carbon Monoxide (CO) levels in air and generates necessary alarms and actions. The system consists of two parts, Carbon Monoxide Monitoring Unit (COMU) and Exhaust Fan Control Unit (EFCU). Wireless communication will connect both units together.
Operation of COMS can be summarized as follows.
1. COMU will measure CO levels in air using a CO sensor module. The module is based on MQ-7 CO sensor which detects CO in the range 20 ppm - 2000 ppm. Generated alarms and actions taken by the COMU will be based on the following table. Source
| Concentration | Symptoms |
|---|---|
| 35 ppm | Headache and dizziness within six to eight hours of constant exposure |
| 100 ppm | Slight headache in two to three hours |
| 200 ppm | Slight headache within two to three hours; loss of judgment |
| 400 ppm | Frontal headache within one to two hours |
| 800 ppm | Dizziness, nausea, and convulsions within 45 min; insensible within 2 hours |
| 1600 ppm | Headache, increased heart rate, dizziness, and nausea within 20 min; death in less than 2 hours |
| 3200 ppm | Headache, dizziness and nausea in five to ten minutes. Death within 30 minutes |
| 6400 ppm | Headache and dizziness in one to two minutes. Convulsions, respiratory arrest, and death in less than 20 minutes |
| 12800 ppm | Unconsciousness after 2–3 breaths. Death in less than three minutes |
2. The COMU will generate the following alarms
Visual: 6 LEDs (2 x green, 2 x orange, 2 x red) lighting will be mapped to CO level 20 ppm to 2000 ppm.
Visual: 16x2 LCD will display CO level, and recommended actions (CO <= 400) or taken actions (CO >= 400).
Audio: Buzzer will generate audio alarm at critical CO levels (CO >= 800 ppm.
3. At CO >= 400 ppm, the COMU will communicate with the EFCU and send a command to turn exhaust fan on.
4. The EFCU will control cut-out valve using a dc motor and exhaust fan. User can manually select the mode of operation (Off, ON, COMU Control).
5. Two way RF communication will be between COMU and EFCU. The COMU will always check on cut-out valve and exhaust fan status. If any failed, alarm (using LCD and buzzer) will be generated to inform the user.
Who has done what beforehand?¶
Many students completed projects related to poisonous gases detection. I used the fablab search and found the following results.
poisonous gas detection system: Will measure poisonous gases in wells and sewage systems. This device will generate an alarm using LCD.
A SHIELD FOR THE 21ST CENTURY Will measure CO in air (and other things) by a sensor connected to the mask. Seems student has not completed working on this.
Project Canary Student mentioned CO detection but had not implemented in final project, only used SDS011 sensor.
Smart Bike Project CO sensor attached to a bike will collect data about air quality in Barcelona city.
My final project is different in many ways.
- It target closed places where usually people stay in.
- Connected to an “action” unit, in my case the action unit is the Exhaust Fan Control Unit (EFCU).
- Inspired by an extreme problem, people loosing their lives.
- Could be adapted in different context like tents used in displaced people and refugee camps.
What will you design?¶
I will design the following components:
- The COMU PCB that connects input, output and communication devices to micro-controller.
- The COMU casing (3D printing).
- The EFCU that connects input, output and communication devices to micro-controller.
- The EFCU casing (3D printing).
- The cutout valve that will be attached to exhaust fan (Laser cutting and/or 3D printing).
What materials and components will be used?¶
| Type | Component | Part Number | Qty. |
|---|---|---|---|
| Communication | Wireless transceiver module | NRF24L01+ 2.4GHz | 2 |
| Input | Push button | Tactile 6 mm | 4 |
| Input | CO sensor module | MQ-7 | 1 |
| Input | Limit switches | Mini LS | 2 |
| Output | LEDs | LEDFAB1206 | 13 |
| Output | LCD | 16x2 LCD | 1 |
| Output | Buzzer | 5V magnetic buzzer | 1 |
| Output | H-bridge | 620-1428-1 | 1 |
| Output | DC motor geared | 12VDC motor | 1 |
| Output | Relay | 5VDC/220VAC | 1 |
| Output | Exhaust fan | 6”/8” 220VAC | 1 |
| Power | Adaptor | 220 VAC - 9 VDC | 2 |
| Power | Voltage regulator | +5 VDC 1A | 2 |
| Power | Voltage regulator | +3.3 VDC | 2 |
| Control | Micro-controller | AtMega328 | 2 |
| Resonator | Ceramic resonator | 8Mhz/16MHz | 2 |
| Resistor | Resistors | 1kOhms, 10kOhms | 19 |
| Capacitor | Ceramic capacitors | 0.1, 1uF, 10uF | 8 |
| Casing | COMU and EFCU | PLA 3DP | 2 |
Where will they come from?¶
Most of the material and components are available in the fablab. Other components (NRF24L01+ 2.4GHz, MQ-7, Exhaust fan) are available in local market.
How much will they cost?¶
Prices below based on digiKey and local market.
| Component | Qty. | Source | UP $ | TP $ |
|---|---|---|---|---|
| Wireless transceiver module | 2 | Local market | 7.04 | 14.08 |
| Push button | 4 | digiKey | 0.16 | 0.64 |
| CO sensor module | 1 | Local market | 7.50 | 7.50 |
| Limit switches | 2 | Local market | 1.05 | 2.10 |
| LEDs | 13 | digiKey | 0.31 | 4.03 |
| LCD | 1 | Local market | 0.31 | 2.11 |
| Buzzer | 1 | Local market | 1.41 | 1.41 |
| H-bridge | 1 | digiKey | 1.80 | 1.80 |
| DC motor geared | 1 | TBC | ||
| Relay | 1 | Local market | 1.76 | 1.76 |
| Exhaust fan | 1 | Local market | 14.08 | 14.08 |
| Adaptor | 2 | Local market | 7.04 | 14.08 |
| Voltage regulator | 2 | Local market | 0.70 | 1.40 |
| Voltage regulator | 2 | Local market | 0.70 | 1.40 |
| Micro-controller | 2 | digiKey | 1.58 | 3.16 |
| Ceramic resonator | 2 | digiKey | 0.39 | 0.78 |
| Resistors | 19 | digiKey | 0.10 | 1.90 |
| Ceramic capacitors | 8 | digiKey | 0.13 | 1.04 |
| COMU and EFCU 10 hours | 2 | Techworks | 2.61 | 26.10 |
The approximate cost is $99.37 (The cost of DC motor and 3will be added later)
What parts and systems will be made?¶
I will make the following components:
- The COMU PCB that connects input, output and communication devices to micro-controller.
- The COMU casing (3D printing).
- The EFCU that connects input, output and communication devices to micro-controller.
- The EFCU casing (3D printing).
- The cutout valve that will be attached to exhaust fan (Laser cutting and/or 3D printing).
What processes will be used?¶
- For COMU and EFCU casing, I will use 3D modeling and 3D printing.
- For COMU and EFCU PCBs I will use PCB design and PCB milling.
- For Cutout valve I will use 2D and/or 3D modeling and Laser cutting and/or 3D printing.
What questions need to be answered?¶
On the coming weeks I need to find out how to build RF communication system between two boards and how to control DC motors.
How will it be evaluated?¶
Evaluation through project development: I will test subsystems before connecting them together. For example, I will send test signals to motor driver and check if the cutout valve is working as required. Another example, I will write a code to send a predefined byte between the boards to test wireless communication.
Evaluation after project development: I will use the system in different CO levels environments and check the response.