<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">All, <div class=""><br class=""></div><div class="">I am building a new board and have to make some design decisions. Before sending to OSHPark, I wanted to see if you all could tell me if I am about to make any mistakes:</div><div class=""><br class=""></div><div class="">1) Powering a Bluetooth LE module using an Arduino IO Pin. I am using the Adafruit Bluetooth LE friend. According to <a href="https://learn.adafruit.com/introducing-the-adafruit-bluefruit-le-uart-friend/current-measurements" class="">this article</a> it should only draw 15.2mA peak current. Looking up the <a href="http://playground.arduino.cc/Main/ArduinoPinCurrentLimitations" class="">ATMEGA 328p specs</a> I see that that it can source 40mA on an IO pin. I know that engineers like to add a “safety factor” so, do you think I would be OK or should I use a FET and have the Arduino simply control it?</div><div class=""><br class=""></div><div class="">2) I am moving away from storing data on a MicroSD card and want to use a FRAM chip instead. BTW, if you have not looked at FRAM it is awesome! I will use the <a href="http://www.fujitsu.com/us/Images/MB85RC256V-DS501-00017-3v0-E.pdf" class="">Fujitsu chip</a> and communicate using i2c. Here is the question, what if I wanted to use an external reader to extract the data from this chip, I could expose the i2c pins on the boar and use a POGO pin reader to connect - that way I would not need to refresh the ATMEGA on the board to change to a data dump sketch. So, I would connect this device to provide power, ground, SDA and SCL. The thing is, I don’t want the ATMEGA on the board to get in the way of this. Could I simply add a pin connected to the board’s RESET pin and hold it low, disabling the onboard processor and leaving the i2c bus available for access?</div><div class=""><br class=""></div><div class="">3) I want to add a date and time stamp to each event I log on the FRAM chip, I am thinking the best format would be UNIX or EPoC time as it will use only 4 bytes. That way each event will use only 4 date/time bytes and one data byte and I can store a year’s worth of data on a 256k chip. Is there a better way to store date and time?</div><div class=""><br class=""></div><div class="">Thank you all for your help,</div><div class=""><br class=""></div><div class="">Chip</div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div></body></html>