|Kickstarter promo image, ©Hello|
Unfortunately, this left the hardware unsupported with no servers to process it's data. The Hello company did initially offer some support for the idea of open sourcing support for their devices but this never got off the ground. Fast forward to 2020 and it has become obvious no one is going to get the original hardware working again. It simply wouldn't make sense in the days of $4 WiFi enabled MCUs to put the effort into reverse engineering the software stack on the Sense. What does make sense is scavenging some of the amazing industrial design and sensors and building a new data logging solution.
|Power board pictured later|
If you have a Hello Sense sitting around and want to replicate what I built, you can pull the Arduino code from my GitHub here: https://github.com/Bostwickenator/HelloTwo.
- Pin reservations on the NodeMCU. GPIO 9 and 10 are special and you need to be careful using them http://smarpl.com/content/esp8266-esp-201-module-freeing-gpio9-and-gpio10
- Timing for the Sharp GP2Y10 is very dependant on capacitor value. I suggest graphing the sensor response and picking the highest point of the curve for your individual circuit instead of relaying on the 280 microseconds specified in the datasheet.
- Docker for windows does not boot on startup. solution on StackOverflow
- Accidentally using 3 instead of D3 for a pin operation on the NodeMCU will compile and will hard reset your device each time it is executed.
- Self heating. The NodeMCU produces a surprising amount of heat. With the device in full powered up state the temperature reported was 3 degrees centigrade higher than the true value. To combat this I put the WiFi module into forced power down this reduced the temperature offset to 1 degree which I compensated for in software.
- The Sharp GP2Y10 response values are incredibly noisy. The values bounce around with a standard deviation of at least 3 bits in the 10 bit ADC on the ESP8266. To get around this, I had to collect a lot of samples and apply a Gaussian filter
- The Sparkfun library for the HTU21D-F crashes the ESP8266.The Adafruit library works perfectly.