UPDATE #1
- Optimize the code by grouping code as a function and adjusting the delay time.
- Add more comments and descriptions.
UPDATE #2
- Include the wake up and sleep cycle for GSM board to save power when the board go to sleep mode.
UPDATE #3
- Remove existing calibration method.
- Apply new calibration method called two-known-weight method.
- Add more comment and description of pin connections between all devices.
- Add the code for waiting user's input as string.
- Remove many unused variables from the program, like g and pi.