Safecast V0.1 R4 Change notes¶

1. Removed header for Amphenol/Shinyei particle sensor. Note, this type of sensor could still be connected to the UEXT header if someone wants to use this type of sensor - we just removed the dedicated header for this.
2. Disconnected pin D33. This pin can be problematic if state can’t be guaranteed at Teensy start up. This pin was used for SPI CS line on UEXT and wifly/XBEE/Lora header. New version is now using pin D32 for the CS line.
3. Added on-board temperature and humidity sensor (I2C). This way the device will always have temperature and humidity regardless of sensor configuration (single sensor, multi-sensor, etc). In previous versions the only temperature sensors were on the gas sensor adaptor boards - so the device only had temperature measurements when the gas sensors were connected.
4. Added mosfet switch for controlling power to wifly/XBEE using IO pin on the Teensy. This way the Teensy can toggle the power to the Wifly if it detects that there is an issue e.g. it is unresponsive.
5. Replaced some of the existing through-hole components - resistors, capacitors - with surface mount components. This makes layout easier. Used the larger of the surface mount packages e.g. SM0805.
6. Added the Safecast logo to the silkscreen (back).