Jan
18
2009
0

Carbon Film 5% Resistor Kit

I decided since I’m going to start prototyping circuits at home I need to get some resistors.  For the last 8 years I’ve mostly used surface mount resistors at work and my old resistor kits from school have long been thrown out.  I’ve done a bunch of searching and found that good old eBay seems to have the best deals on resistor kits.  The eBay store Sunpec has some good deals on kits.  The kit I chose was Carbon Film Resistor 5% 1/4W Assortment Kit.  The kit includes 50 different values with 50 pieces of each value, that’s 2500 resistors.  The kit cost $18.99 which included shipping from China.  I received the kit about a week after placing the order and all the resistors were there.  There were a few values of resistors that didn’t match the description but they were really close…they probably ran out of the listed value and used the closest replacement.

The packs were not marked so I had to go through and write the value on each bag.  I felt a little embarassed since I’ve been working with surface mount resistors for so long I had to break out the resistor color codes, but o-well.

Each value of resistor is sealed in a plastic bag like this:

resistor_pack-10k

Here is the entire kit:  (The kit doesn’t come in the box)

resistor_kit

And just for prosperity here is a good chart of the resistor color codes:

resistorcolorcodes

Written by KludgeGuru in: Electronics |
Dec
07
2008
0

Choosing a Microcontroller Family

There are a lot of microcontroller options out there.  I’ve only used a couple families of microcontrollers, PIC from www.microchip.com and a basic stamp from www.parallax.com.  PIC works great for my projects at work but for my home projects I think I want to try something different.  I would also like to have experience with a different microcontroller to add to my skill set.

I’ve come up with a short list of requirements for my home hobby MCU family.

  • Low cost development tools.  I’m not rich so I need to find a MCU family that has low cost or free development tools.  I could use the PIC development tools that I use at work but as I mentioned before I want to try something different.
  • Cheap or Free C Compiler.  I don’t want to program in Assembly.
  • Low cost in-circuit debugger.  My code never works the first time so I need to be able to step through the code to find out what I did wrong.
  • Through-hole DIP packages.  I would like the MCUs to be available in through-hole packages so I can easily make prototype boards without having to layout a PCB, cause that costs money.
  • Inexpensive development board so I can tinker with a circuit that is pre-built.
  • The actual chips need to be inexpensive and widely available so I don’t have to order them from an exotic vendor and wait weeks for delivery.
  • On board peripherals such as USART, USB, I2C, Timers, A/D Converters and Pulse Width Modulators.

Looking back at my list, the main factor seems to be cost.

After much searching and reading about the different MCUs available today it seems as if the Microchip PIC and the Atmel AVR are the top two for hobbyists.  They both seem to meet most of my above requirements but the Atmel AVRs seem to have more free development tools such as compilers.

I found this great guide to different types of microcontroller families for beginners written by somebody named Sam.

Beginners Guide to Microcontrollers

So my choice for a microcontroller family for my home projects is the Atmel AVR.

Written by KludgeGuru in: AVR,Electronics |

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