pimometer

=======

Remote Thermocouple Monitor

Goal

PCB to report temperature from 4 k-type thermocouples over wireless, for viewing on a smartphone.

• Form Factor: Raspberry Pi Shield
• Power Source: Initially battery powered with on/off switch. ** Future: solar or thermoelectric generator(TEG) using heat from oven.
• Thermocouple Measurement: MAX31855 Datasheet via SPI in an SO-8 package
• Wireless Connection: WiFi Dongle
• Configuration/Display: via SD Card ** LEDs for display- 1 LED for wireless connection
• Smartphone Display: Ideally would be accessible across multiple smartphone platforms, so no native app. ** Better to have a webserver run on the device itself, i.e. Flask

Design

Raspberry Pi pinout

• Clock: 11
• MISO: 9
• CS1: 18
• CS2: 23
• CS3: 24
• CS4: 25
• Also need +3.3V and ground available to shield

Software Design

• When Flask receives request for current temperatures, o

Service installation

chmod 755 nodejs sudo cp nodejs /etc/init.d sudo update-rc.d nodejs defaults

Avahi Installation

sudo apt-get install avahi-daemon sudo insserv avahi-daemon

Cost Comparison

Component | Raspberry Pi | Arduino (TC shield + wifi breakout) -----------+----------------+------------------------------------- Controller | $35 | $7 Crystal | | $1 Regulator | | $2 Wifi | $15 | $35 SD card | $8 |

Subtotal | $58 | $45

TC shield

4xTC | $32 Custom PCB | $15?

Enclosure | LiPo Battery | LiPo Charger |