Razor 9 DOF IMU JST Connector?

Hello all!

Sorry if this is the wrong forum, I wasn't sure which of the many forums to post in. I've duplicated this post from Project Guidance because after thinking about it, it's probably a more suitable question for General Electronics. My apologies for the duplicate posting.

I've been looking at my Razor 9 DOF IMU and can't seem to find the right type of JST connector to hook it up to my LiPo.

I was told by a friend that I would need to power it externally as the draw from my seeeduino mega is too great after hooking up my GPS module so i'm looking to try and find the right connector for the job.

So far, i've ordered three different types of JST connectors and non of them seem to fit at all. Can anyone identify the correct name of the connector on the Razor?

Here's an image for reference: http://airhacks.org/wp-content/uploads/9DOF_razor.jpg

Looking around on the internet, all I can seem to find are the same connectors i've already ordered. Any help identifying this would be most appreciated.

As an aside: the razor tech sheet says:

"The 9DOF operates at 3.3VDC; any power supplied to the white JST connector will be regulated down to this operating voltage."

Am I correct in assuming that if I feed the IMU straight from my 11.7v LiPo, it will regulate the voltage down to 3.3v or do I need to regulate the voltage further? It seems to play nice with my seeeduino mega but I wanted to be sure before I fry £80 worth of hardware on a hunch...

Thanks for reading, any help would be greatly appreciated!

Kind regards,

Zack Brown

CaptainRedmuff:
I was told by a friend that I would need to power it externally as the draw from my seeeduino mega is too great after hooking up my GPS module so i’m looking to try and find the right connector for the job.

The Seeeduino should be able to power it without any problem. The onboard regulator supplies up to 500ma and has thermal shutdown protection if you get it too hot. Look for the part marked “U3” on your Seeeduino with “1117” printed on it – that’s the 3V regulator; if you feel it getting too hot then stop.

CaptainRedmuff:
As an aside: the razor tech sheet says:

“The 9DOF operates at 3.3VDC; any power supplied to the white JST connector will be regulated down to this operating voltage.”

Am I correct in assuming that if I feed the IMU straight from my 11.7v LiPo, it will regulate the voltage down to 3.3v or do I need to regulate the voltage further? It seems to play nice with my seeeduino mega but I wanted to be sure before I fry £80 worth of hardware on a hunch…

Yes, it should regulate it fine. If you’re using this with an RC car or plane It would be preferred if you dropped the 11.7V from the LIPO to 5V supplied from a “BEC”/“UBEC” if it’s available however, as the BEC is more efficient at regulating current. The linear regulators used on the Razor and Seeeduino inefficiently dissipate the 11.7V - 3.3V= 8.4V * amperage as heat so obviously 5V - 3.3V = 1.7V * amperage would be cooler.

Don’t forget to set your Seeeduino to 3.3V when you’re using it with the Razor. Can’t have the Seeeduino popping 5V signals at a 3.3V board…

Awesome, thank you very much for your reply.

You also cleared up another one of my questions regarding the 3.3v and 5v switch. I assumed this was to set the reference voltage but it seems this is the direct output. However, i'm confused about pin voltages now :/

By setting the switch to 3.3v, does that mean that the 5v rail on my board will output 3.3v also? And vice versa; setting the switch to 5v will output 5v on the 3.3v rail?

I'm just trying to gather as much info as possible before I start frying all my hardware with incorrect power supplies. I really need to pop to Maplin and buy a voltammeter :P

Also, I read that the maximum draw from a pin is 40mA. I assume this is "per pin" rather than from the entire board as a whole?

I'm looking to power my GPS (3.3v) and my TxRx Crystal (4.8v) from the arduino but am starting to think I'm going to need regulators for everything now.

Ahhh, the joys of being a n00b :/