1.8 KiB
Electronics
Some basic tipe for new embedded Eletronics programmers
Use of DDx, PORT and PIN registers:
- DDx: Choice of pins state: Inputs or Outputs
- PORT: Set the outputs state, rules the outputs (ex : set Pin to 0)
- PIN: Reads the inputs states, or toggle values. (ex: Toogle Pin)
Easily set a bit to 0 in a register:
PPR=PPR & 0b01111111
Easily set a bit to 1 in a register:
PPR=PPR & 0b01111111
Debug hardware errors after optimization:
In case your C code does not work any more after Optimization (-O2 -O3)
- Check if global variables are used in interruptions
- Try to set them as volatile
Hazardous hardware resets:
Check if your interruptions are initialized in your code !
Otherwise, the C code will automatically jump to a non-existing address, causing the reset.
I/O problems:
In case of I/O problems in your code, check your Hardware and especially your resistors
Try to unsolder them and run the code.
Embedded electronics main architecture code:
Generally, embedded architecture software is divided into 3 main layers :
- Drivers: Whose job is to interact with Hardware at a low level (Ex : Read spi data)
- Services/Components: Intermediate layer, interface between drivers and Applications
- Application: Higher layer, which aims at achieving the main purpose of the project (Ex: Calculate movement using an accelerometer) Here is a simple drawing to get the idea:
NOTE: The main idea behind that when you code is the reuse! The application may not be reusable, but drivers and components must !
If you did good, you should be able to use the same application in two architectures, changing only components and drivers.