108 lines
4.1 KiB
C
108 lines
4.1 KiB
C
|
/*
|
||
|
|
* MIT License
|
||
|
|
*
|
||
|
|
* Copyright (c) 2018 Nis Wechselberg
|
||
|
|
*
|
||
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
||
|
|
* of this software and associated documentation files (the "Software"), to deal
|
||
|
|
* in the Software without restriction, including without limitation the rights
|
||
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
||
|
|
* copies of the Software, and to permit persons to whom the Software is
|
||
|
|
* furnished to do so, subject to the following conditions:
|
||
|
|
*
|
||
|
|
* The above copyright notice and this permission notice shall be included in all
|
||
|
|
* copies or substantial portions of the Software.
|
||
|
|
*
|
||
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
||
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
||
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
||
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
||
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
||
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
||
|
|
* SOFTWARE.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Firmware for MiCS-6841-based I2C adapter board.
|
||
|
|
* Implements a behaviour compatible to the Seeedstudio
|
||
|
|
* Grove Mutichannel Gas Sensor-library.
|
||
|
|
*
|
||
|
|
* Using ATmega core from:
|
||
|
|
* https://raw.githubusercontent.com/carlosefr/atmega/master/package_carlosefr_atmega_index.json
|
||
|
|
*
|
||
|
|
* Pin mapping:
|
||
|
|
* Heater Enable (out): PB0 / Digital 8 (Active low)
|
||
|
|
* NH3 resistance (in): PC0 / Analog 0
|
||
|
|
* RED resistance (in): PC1 / Analog 1
|
||
|
|
* OX resistance (in): PC2 / Analog 2
|
||
|
|
*
|
||
|
|
* SDA: PC4 / Analog 4
|
||
|
|
* SCL: PC5 / Analog 5
|
||
|
|
*/
|
||
|
|
#ifndef MiCS6814_V1_H
|
||
|
|
#define MiCS6814_V1_H
|
||
|
|
|
||
|
|
|
||
|
|
// Include Wire library for I2C support
|
||
|
|
#include <Wire.h>
|
||
|
|
#include <EEPROM.h>
|
||
|
|
|
||
|
|
|
||
|
|
// Pin mapping constants
|
||
|
|
#define HEATER 8
|
||
|
|
#define NH3_IN A0
|
||
|
|
#define RED_IN A1
|
||
|
|
#define OX_IN A2
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* I2C commands
|
||
|
|
*
|
||
|
|
* Taken from Grove Mutichannel Gas Sensor Library, just some renaming done here
|
||
|
|
*/
|
||
|
|
#define CMD_GET_NH3 1 // Retrieve current resistance for NH3 sensor channel
|
||
|
|
#define CMD_GET_RED 2 // Retrieve current resistance for RED sensor channel
|
||
|
|
#define CMD_GET_OX 3 // Retrieve current resistance for OX sensor channel
|
||
|
|
#define CMD_GET_ALL 4 // Retrieve all sensor resistance channels
|
||
|
|
#define CMD_CHANGE_I2C 5 // Change I2C address of the sensor
|
||
|
|
#define CMD_READ_EEPROM 6 // Read stored uint16_t data from EEPROM (MSB is transmitted first)
|
||
|
|
#define CMD_SET_R0 7 // Set custom R0 values
|
||
|
|
#define CMD_GET_R0 8 // Retrieve current R0 values
|
||
|
|
#define CMD_GET_R0_DEFAULT 9 // Retrieve default R0 values
|
||
|
|
#define CMD_CONTROL_LED 10 // Control status LED (no LED on my board, but Grove supports is, so ... meh!)
|
||
|
|
#define CMD_CONTROL_PWR 11 // Heater control
|
||
|
|
|
||
|
|
|
||
|
|
/* EEPROM Addresses
|
||
|
|
*
|
||
|
|
* These match the addresses used in the Grove library
|
||
|
|
* If the library was implemented in a sensible fashion I would
|
||
|
|
* be free to use my own mapping here.
|
||
|
|
* However, the library accesses eeprom data directly quite frequently, so ... meh!
|
||
|
|
*/
|
||
|
|
#define EEPROM_VERSION_ID 0 // Identifier for the current version, Grove uses value 1126 to identify version 2 of their sensor.
|
||
|
|
#define EEPROM_R0_DEFAULT_NH3 2
|
||
|
|
#define EEPROM_R0_DEFAULT_RED 4
|
||
|
|
#define EEPROM_R0_DEFAULT_OX 6
|
||
|
|
#define EEPROM_R0_NH3 8
|
||
|
|
#define EEPROM_R0_RED 10
|
||
|
|
#define EEPROM_R0_OX 12
|
||
|
|
#define EEPROM_I2C_ADDR 20
|
||
|
|
|
||
|
|
#define DATA_VERSION_ID 1126
|
||
|
|
#define DATA_I2C_ADDR 0x04
|
||
|
|
#define DATA_R0_DEFAULT_NH3 123
|
||
|
|
#define DATA_R0_DEFAULT_RED 123
|
||
|
|
#define DATA_R0_DEFAULT_OX 123
|
||
|
|
|
||
|
|
|
||
|
|
// Runtime data
|
||
|
|
uint32_t timer; // Timer value of last update
|
||
|
|
uint16_t resistanceNH3; // Current resistance value for NH3 channel
|
||
|
|
uint16_t resistanceRED; // Current resistance value for RED channel
|
||
|
|
uint16_t resistanceOX; // Current resistance value for OX channel
|
||
|
|
uint8_t i2CResp[6]; // Buffer for I2C response
|
||
|
|
uint8_t i2CRespLength; // Amount of bytes to be sent to master
|
||
|
|
|
||
|
|
#endif
|