LTC6803-3 SPI

Hey Guys, I am attempting to interface a LTC6803-3 battery managment IC with an Arduino pro mini.
I have never used SPI and after looking into it some I am a bit confused.
Here is the datasheet

On the LTC6803 its listed

CSBI
SDO*
SDI
SCKI

MAIN SPI PORT
TO HOST µP OR
NEXT LTC6803-1
*REQUIRES 1k PULL-UP RESISTOR AT HOST DEVICE
(SIGNAL NOT USED FOR INTER-IC COMMUNCATION)

On the Arduino pro mini its

SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins support SPI communication, which, although provided by the underlying hardware, is not currently included in the Arduino language.

So I think it goes like this

LTC6803 <> Arduino
43 14
44 13
42 15
41 16

And it asks for a pullup ressitor on SDO, so that means one end of the 1K resistor is connected to the trace between SDO<>MOSI and the other end is connected to VCC, correct?

One other question that is not really Arduino specific… on page 13 of the datasheet it shows the LTC6803 daisy chained with a couple other ones. I do plan on being able to use a second one if needed, In the schematic it just lists a “digital Isolator” I have never used one of those… wouldnt have any idea what to look for :frowning:
It also lists that as 3V and the MPU as 3V, should I use a 3V arduino pro mini to make it easier?

So, no one has any input? Just looking for a little help so I don’t build this board and get it completely wrong hahahaha

SPI is supported by the Pro-mini, It works well.. that having been said.. It's time for you to do some reading about your programming problem. You might start here: http://arduino.cc/en/Reference/SPI and yes the Pro-Mini will work at 3V3 but at 8 MHz only.

Bob

LTC6803 <> Arduino
43 14
44 13
42 15
41 16

Your Arduino don’t have a pin labeled “14” or “16”. If you count the pins, you should always describe how you do that because there a different ways, you know?

SDO (43) goes to MISO (12, the label not the count) and SDI (42) goes to MOSI (11), otherwise you’ll get a short circuit.

And it asks for a pullup ressitor on SDO, so that means one end of the 1K resistor is connected to the trace between SDO<>MOSI and the other end is connected to VCC, correct?

Almost. As already mentioned SDO is connected to MISO and the resistor must be at least a 10k because the max. sinking current of the SDO pin is 500µA.