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A good and motivational project imo can be to buy a simple sensor board for the Arduino, and write a driver yourself for it (even if drivers exist). Pick a simple sensor - some will require you to do all kinds of hoops and loops, but others are more like "startup, trigger sensor read, read out". For this part, it's also fun to have a logic analyzer (starts at about 10 bucks) to see the change in code manifest on physical pins. It's also helpful to see that what you think you are doing, is actually happening. Eg, the SPI Chip select pin may be inverted (high when should be low and vice versa). Then start off with a simple program that does init, and periodically read the sensor. Perhaps adding thresholds that trigger eg a LED. Then you can extend this to pipe over serial port to the rpi and push it to some server of your choice (eq mqtt), or display on a local webserver dashboard. Go with sensors that are ordinary SPI or I2C, not some one-wire-protocol. Suggestions, BMP180 (temp, RHum), TSL2561 (light). Have fun! edit: if you are doing it on the Arduino, you can start off with the arduino spi/i2c libs, and later on if you wish, fire up the AVR datasheet (or whatever cpu is on your arduino) and implement i2c/spi yourself by changing registers etc on the cpu. |