Engine Monitor

Price: $4

Part: M960909
Type: 4 wire platinum oxygen sensor
Product Fit: Direct Fit
Connector Gender: Male
Hex Size: 7/8 in.
Mounting Style: Threaded-in
Thread Size: M18-1.5
Warranty: 1-year, unlimited-mileage warranty
Wire Length: 22.75 in.

http://www.carparts.com/details/Replacement/Oxygen_Sensor/M960909.html?TID=gglpla&origin=pla&gclid=CM2v-_HC-MsCFUiGfgod5NAOHw&redirect=1

$7 - GY-87 10DOF includes accelerometer, compass, air pressure, temperature

gyro and accelerometer MPU6050 3 axis
digital compass hmc5883l 3 axis
pressure and temperature bmp085 1 axis
interface - i2c bus

Code I tested for proof of concept https://github.com/richardghirst/PiBits/tree/master/MPU6050-Pi-Demo

Purchase Source

http://www.aliexpress.com/item/GY-87-10DOF-Module-MPU6050-HMC5883L-BMP180-GY87-Sensor-Module/1986963611.html?spm=2114.01010208.3.2.mqhaup&ws_ab_test=searchweb201556_0,searchweb201602_1_10036_10035_301_10034_507_10032_10020_2010016_10017_10005_10006_10021_10022_401_10018_10019,searchweb201603_9&btsid=6cc51804-d95d-4fd9-8265-85f72fdd3bcf

Specifications:

$10 price

Part #SKU237545
Working Voltage: 5VDC
Output Voltage: 0.5-4.5 VDC
Sensor material: Carbon steel alloy
Working Current: ≤10 mA
Cable length: 19cm
Working Pressure Range: 0-175psi (0-1.2 MPa)
The Biggest Pressure: 2.4 MPa
Destroy Pressure: 3.0 MPa
Working TEMP. Range: 0-85 degree
Storage Temperature Range: 0-100 degree
Measuring Error: ±1.5 %FSO
Temperature Range Error: ±3.5 %FSO
Response Time: ≤2.0 ms
Cycle Life: 500,000 pcs
Stainless steel is durable, sealed waterproof line

http://www.aliexpress.com/item/Pressure-Transducer-Sensor-Oil-Fuel-for-Gas-Water-Air/32523806518.html?spm=2114.01010208.3.2.DqUaS5&ws_ab_test=searchweb201556_0,searchweb201602_1_10036_10035_301_10034_507_10032_10020_10017_10005_10006_10021_10022_401_10018_10019,searchweb201603_9&btsid=ab83ec34-d7a0-4e73-ac47-d5eaf2bef720

$1 - The DHT-11 will provide outside temperature and humidity.

http://www.aliexpress.com/item/1pcs-DHT11-Digital-Temperature-and-Humidity-Sensor/32246685842.html?spm=2114.01010208.3.2.FZ68t8&ws_ab_test=searchweb201556_0,searchweb201602_1_10036_10035_301_10034_507_10032_10020_10017_10005_10006_10021_10022_401_10018_10019,searchweb201603_9&btsid=0e326206-f43b-4cd1-b5ea-df8c0ffdd9c0

$28 - 2ch HD 800 x 480 7 Inch Color TFT LCD Monitor. I have owned one of these in the past and it works very well with micro processors.

http://www.aliexpress.com/item/DU-NEW-and-High-Quality-HD-800-x-480-7-Inch-Color-TFT-LCD-Car-Rear/32553771346.html?spm=2114.01010208.8.80.HFOw9T

Aliexpress has $2-3 K Type Nylon Braided 800C 6mm Screw Thermocouple Temperature Sensor 1M 3.3Ft. The other option was 2M ohm, but the selection was poor.

Application:

4 CHT, 4 EGT

http://www.aliexpress.com/item/Hot-Sale-High-Quality-Stainless-Steel-High-Temperature-0-To-800-Degree-Thermocouple-K-Type-1000mm/32631426082.html?spm=2114.01010208.3.81.BgLA6r&ws_ab_test=searchweb201556_0,searchweb201602_1_10036_10035_301_10034_507_10032_10020_10017_10005_10006_10021_10022_401_10018_10019,searchweb201603_9&btsid=eeb69e66-6739-49d5-9b5c-14a00a8f58ad

Because this project will require considerably more IO ports that any micro-controller can provide, I identified the best IO expansion candidate as the MCP3008. It is a $4 16pin dip ADC with 8ch@10bits over SPI interface. Since SPI can be daisy chained and only requires 4 IO pins, perhaps 2 of them will serve all the analog interface needs.

Application

16ch total = 4ch EGT, 4ch cht, 1ch oil pressure, 1ch oil temp, 1ch fuel psi, 1ch fuel gph, 1ch manifold psi, 1ch air temp, 1ch humidty, 1ch air psi

Code for proof of concept I tested http://www.hertaville.com/interfacing-an-spi-adc-mcp3008-chip-to-the-raspberry-pi-using-c.html

Resources:

http://ww1.microchip.com/downloads/en/DeviceDoc/21295d.pdf

www.microchip.com/wwwproducts/en/en010530

https://learn.adafruit.com/raspberry-pi-analog-to-digital-converters