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Step 2Show Stoppers
There are a number design considerations that might immediately reduce your number of choices a great deal.
Programability and Reprogramability:
At this point in time, I would say that a hobbyist should only consider microcontrollers that have internal flash or eeprom program memory and can be erased and reprogrammed a substantial number of times. There are also micros that can be used with external memory (adds complexity and expense), UV erasable micros (usually quite expensive due to the special packaging), one-time programmable chips (potentially usable after you have a working design, but losing their price advantage anyway), and mask-programmed chips (essentially useless.)
Peripherals:
If you want your microcontroller to have built in Ethernet, CAN, USB, or even multiple serial ports, many common choices are going to be eliminated. Some peripherals can be handy to have: UARTs, SPI or I2C controllers, PWM controllers, and EEPROM data memory are good examples, even though similar functionality can frequently be implemnented in software or external parts.
It's convenient if output pins can supply reasonable amounts of current for driving LEDs or transistors directly; some chips have 5mA or less drive capability.
Physical packaging:
Hobbyists are somewhat limited is the packages they are able to deal with, from a prototyping, PCB fabrication, and/or soldering. That 256 ball BGA coldfire CPU may be sweet, but it's effectively unusable by mere mortals. Microcontrollers available in 0.1in DIP packages are much easier to deal with. Probably anything with a pin spacing smaller than 0.05in should be viewed with some skepticism.
Memory:
The size of memory may be an important consideration. Some micros have as few as 256 innstructions and 16 bytes of RAM. You can do a lot in that sort of space (believe it or not), but not everything. Moreover, while you can frequently upgrade to a "bigger chip", some chip families have relatively small memory limits imposed by their architecture, so even the biggest chip you can get will have only 8k instructions (for example.) RAM (data memory) is usually scarce in microcontrollers; some algorithms require substantial RAM to be implemented in a straightforward manner, and it may be worthwhile looking for a micro with a lot of RAM (or external RAM expansion capabilities) if that's the sort of thing you had in mind. (For instance, implementing TCP/IP networking protocols in a micro whose total RAM space is less than used by a typical ethernet packet is likely to be ... interesting.)
Programability and Reprogramability:
At this point in time, I would say that a hobbyist should only consider microcontrollers that have internal flash or eeprom program memory and can be erased and reprogrammed a substantial number of times. There are also micros that can be used with external memory (adds complexity and expense), UV erasable micros (usually quite expensive due to the special packaging), one-time programmable chips (potentially usable after you have a working design, but losing their price advantage anyway), and mask-programmed chips (essentially useless.)
Peripherals:
If you want your microcontroller to have built in Ethernet, CAN, USB, or even multiple serial ports, many common choices are going to be eliminated. Some peripherals can be handy to have: UARTs, SPI or I2C controllers, PWM controllers, and EEPROM data memory are good examples, even though similar functionality can frequently be implemnented in software or external parts.
It's convenient if output pins can supply reasonable amounts of current for driving LEDs or transistors directly; some chips have 5mA or less drive capability.
Physical packaging:
Hobbyists are somewhat limited is the packages they are able to deal with, from a prototyping, PCB fabrication, and/or soldering. That 256 ball BGA coldfire CPU may be sweet, but it's effectively unusable by mere mortals. Microcontrollers available in 0.1in DIP packages are much easier to deal with. Probably anything with a pin spacing smaller than 0.05in should be viewed with some skepticism.
Memory:
The size of memory may be an important consideration. Some micros have as few as 256 innstructions and 16 bytes of RAM. You can do a lot in that sort of space (believe it or not), but not everything. Moreover, while you can frequently upgrade to a "bigger chip", some chip families have relatively small memory limits imposed by their architecture, so even the biggest chip you can get will have only 8k instructions (for example.) RAM (data memory) is usually scarce in microcontrollers; some algorithms require substantial RAM to be implemented in a straightforward manner, and it may be worthwhile looking for a micro with a lot of RAM (or external RAM expansion capabilities) if that's the sort of thing you had in mind. (For instance, implementing TCP/IP networking protocols in a micro whose total RAM space is less than used by a typical ethernet packet is likely to be ... interesting.)
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My mailboxcyyww@sina.cn
Engineering Do not consider the cost We use the STC of the MCU
Heard of it,
Cheap and feature-rich
FLASH Great 32K 64K
My mailboxcyyww@sina.cn
Engineering Do not consider the cost We use the STC of the MCU
Heard of it,
Cheap and feature-rich
FLASH Great 32K 64K
My mailboxcyyww@sina.cn
Engineering Do not consider the cost We use the STC of the MCU
Heard of it,
Cheap and feature-rich
FLASH Great 32K 64K