Table of Contents
EEPROM Shield Kit Tutorial
Product Description:
The EEPROM Shield Kit allows you to build a Digispark shield which connects a 256 kbit serial electrically erasable PROM (EEPROM) memory IC to the Digispark development board. The IC used is the Microchip 24LC256 and it communicates with the Digispark over the I²C bus. The EEPROM Shield can be used to store data even after the device is powered off. The IC has an endurance rating of over 1 million write/erase cycles and its rated data retention is more than 200 years.
This is an unassembled kit and requires basic soldering. This is designed for use with the Digispark development board, which is not included.
Parts:
| Part | Quantity | Identification |
|---|---|---|
| EEPROM Shield PCB | 1 | |
| 4.7K (4K7) Ohm 1/4W resistor 1% or 5% | 2 | Yellow - Violet - Red |
| 8 pin DIP socket | 1 | |
| 24LC256 EEPROM IC | 1 | |
| 1x40pin male 0.1“ pitch header | 9 pins worth | |
Resistor Values: For more information on how to identify the value of the resistors we recommend these sites: A nice simple resistor calculator: http://www.ealnet.com/m-eal/resistor/resistor.htm A comprehensive article on identification: http://www.diyaudioandvideo.com/Electronics/Color/
Soldering: If you are new to soldering we recommend the following tutorials: Soldering Basics (http://www.sparkfun.com/tutorials/106) and Soldering Crash Course from the folks at Sparkfun (http://www.sparkfun.com/tutorials/354). How to solder from the Curious Inventor: http://store.curiousinventor.com/guides/How_to_Solder
Adafruit has this excellent guide that starts with the tools needed and then shows detailed pictures, including some of the common problems that beginners experience (http://learn.adafruit.com/adafruit-guide-excellent-soldering)
We assume for these assembly instructions that you know the basics of thru-hole soldering. If you don't check out the links above, these boards are very easy to solder - we promise!
Assembly:
NOTE: If you have a “Model B” board you may need to cut the trace to the onboard LED before using any I2C devices - Find out how to tell which board you have and what to do here: modelbi2c
Empty kit bag (or if using a raw PCB, aquire parts) and verify contents. Note for Kickstarter Backers and Pre-orders: Headers are not included in each kit bag, but the entire order came with more than enough headers for all kits.
Solder resistors one at a time. Solder the leads and clip off the excess. Repeat for all resistors.
Insert the 8 pin DIP socket into the board matching the indention cut out on one end with the indention printed on the board.
Cut a length of male headers 6 pins long and one 3 pins long. Insert into corresponding positions (on the bottom of the board) and solder each pin.
Tip: Inserting the headers into a breadboard and then placing the board on top can make this process easier.
Note: If you are using stackable headers, use them here instead of the standard male headers.
Insert the 24LC256 EEPROM IC into the 8 pin DIP socket matching the indention cut out on one end with the indention on the socket.
Your EEPROM shield is complete!
Programming:
*TROUBLESHOOTING NOTE: If you experience trouble writing to the EEPROM try connecting a jumper wire from Pin 4 of the IC (or any GND) to Pin 7 of the IC (Pins: http://ww1.microchip.com/downloads/en/devicedoc/21203m.pdf) - some boards may be missing this connection, we are looking into it further.*
The pin connections are as follows:
Digispark P0 → SDA Digispark P2 → SCL
The I2C Address is 0x50
Please refer to the EEPROM example included with the Digispark Arduino Addon.
