https://github.com/ieb/canpressure

NMEA2000 Sensor based on ATTiny3224 for Pressure, Temperature, Humidity
https://github.com/ieb/canpressure

Last synced: 3 months ago
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NMEA2000 Sensor based on ATTiny3224 for Pressure, Temperature, Humidity

• Host: GitHub
• URL: https://github.com/ieb/canpressure
• Owner: ieb
• Created: 2022-07-10T10:32:06.000Z (almost 3 years ago)
• Default Branch: main
• Last Pushed: 2023-09-09T06:56:04.000Z (almost 2 years ago)
• Last Synced: 2023-09-09T07:41:31.542Z (almost 2 years ago)
• Language: G-code
• Size: 674 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# Can Pressure sender

* Emits PGN  130310L  Outside Environmental parameters and 130311L Environmental parameters with temperature, pressure, humidity from a BME280 sensor.

* Draws about 10-15mA. Uses a Attiny3224, MCP2551 CAN, and TJ1050.

* Attiny runs at 16MHz, but could almost certainly run slower for lower power consumption.

* PCB in pcb/ measures 66mmx27mm and is powered by 12v from NMEA2000 bus, 5V via a AMS1117, BMP280 module has its own 622K 3v regulator and level shifters.

* Needs a UDPI Programmer (I am using a UNO based programmer)

* Header for TTL Serial debugging using single character command line input.

# Pins and Layout

    -------------------------------------------

    |             a b c d e                   |

    | A                             AMS1117   |

    | B  TJ1050                               |

    | C                   ATTiny              |

    | D        MCP2551    3224       BME280   |

    |                                         |

    -------------------------------------------

    Debug and Programming Header

    a GND

    b 5V

    c UDPI

    d RX

    e TX

    NMEA2000 Interface

    A 12V

    B GND

    C CanL

    D CanH

![](pcb/CanPressure-brd.svg)

![](pcb/CanPressure.svg)

# Command line on TTL

    Battery Monitor - key presses

        - 'h' or '?' to show this message

        - 's' show status

        - 'd' toggle diagnostics

        - 'r' read sensor

        - 'S' setup

        - 'R' reset

        - 'F' factory reset

* R will cause the Attiny to reboot.

* S enters setup allowing some EEPROM parameters to be set 

* F resets the EEPROM to the Factory settings

* r reads the sensors and dumps to serial.

* d toggles disagnostic output which includes CAN Frame data 

* s reports current status including packet counts, MCP Voltage and temperature.

# Developing

* Uses PlatformIO in VSCode

* Before flashing for the first time set the fuses to ensure that the chip has the correct clock. `pio run -t fuses`

* To build `pio run -t upload`