Help Designing a SDC GPS logger

Thread Starter

presflan

Joined Mar 28, 2016
5
Good morning all!

I am new to electronic design and I am working on a project to Design a low power 3.3v GPS data logger with a SD Card. I was going to Try and use the PIC24FJ128GB204 microcontroller (3.3v), the ADXL362 Accelerometer (2v), the Jupiter SE868-AS GPS module, a LP29851M5-3.3/NOPB voltage regulator and hopefully you guys can steer me in the right direction with a SDC card.

So any advice, design ideas, schematics that you guys could provide, pit falls to avoid, and how to start my design would be very helpful. I will be using altium to design my schematic and PCB layout.

Thanks,

P
 

Thread Starter

presflan

Joined Mar 28, 2016
5
Good Morning Sir,

Thanks for the reply. My experience has been in the schematic level of solid state RF filtering components (mulit-plexers, quad plexers ect) and designing RF signals for radar jammers. So electronic PCB design and working with small scale electronics are very new to me.

I just got done with Designing and prototyping a PCB board to interface with a BeagleBoard a low-power open-source hardware single-board computer. The design was very simple and only had one resistor, one inductor, UFL connector, a GPS engine, and a GPS Transceiver. I used this project as a way to self train myself of using a LPKF CNC machine, Laser Prototyper, Electro Plating Tank, a pic n place machine, and a reflow oven. So know that I understand the prototyping equipment and how to generate Gerber files with Altium and spin a quality board I am wanting to tackle more completed electronic designs and further my skills with Alituim. It was super simple and not complex at all. I am still very new to Altium and haven't gotten to the point of finding an efficient way to pull foot prints off a library or generate new foot prints for a PCB layout. So that's my basic experience with electronic design and I am an newbie.

Right now I feel a bit over whelmed on how to figure out if the components I am looking at will work, how to design a schematic using those components and what is the best way to simulate the out puts on a schematic design using Altium before I buy parts for this logger. I am even unsure of how or were to get a foot print for a components I am thinking about using at the schematic level so that Altium will spit out a PCB lay out.

So at this point I am just wanting to focus on generating a schematic and lay it out correctly in alitum and pic out the correct componets that will work. From there I will work my PCB layout design in altium.

Thanks,

P
 

kubeek

Joined Sep 20, 2005
5,794
You bought LPKF just to be able to do prototypes? Wow, i would stick with pcb board houses until I knew that I really needed one.
Nevertheless, I suggest you start with a block diagram. Everything seems to be able to be powered from 3.3V, so you should have it quite easy.
The GPS module looks like trouble, you will have very hard time trying to solder the LGA package to a pcb, something that has the pads on the side as well will be much easier to use.
 

Thread Starter

presflan

Joined Mar 28, 2016
5
So you think its going to be an issue with the GPS module even if I am not hand soldering it? I was going to cut out a Stencil use soilder paste and use the reflow oven, but if you highly recommend not using it I guess I could try and find another one. The thing that I am looking at is trying to keep the power draw down as low as possible.

Do you have any recommendations for a Micro SDC Chip module to go on the board? that really the last component I think I need spec out.

I will work on a block diagram and post it soon for you to laugh at!

Well the command I work for bought the stuff hired me in and said, "well you are an electrical engineer you know how to run all this stuff right??" lol
 

kubeek

Joined Sep 20, 2005
5,794
So you think its going to be an issue with the GPS module even if I am not hand soldering it? I was going to cut out a Stencil use soilder paste and use the reflow oven, but if you highly recommend not using it I guess I could try and find another one. The thing that I am looking at is trying to keep the power draw down as low as possible.
Well if you want to go with a stencil and reflow, then it probably should work ok.

Do you have any recommendations for a Micro SDC Chip module to go on the board? that really the last component I think I need spec out.
What is that, did you mean a micro-sd card holder?
 

Thread Starter

presflan

Joined Mar 28, 2016
5
Good morning Sir, Hope you are doing well.

This is an example of what I am talking about in regards to an SDC https://www.pololu.com/product/2587. My main concern is most of the modules are 5v units that have level shifters to and voltage regulators to drop to 3v. I am not seeing a module that is just 3v and since I am only running a 3.3v battery I don't think the ones I am looking at will work.
 

kubeek

Joined Sep 20, 2005
5,794
You got it wrong, all SD cards are 3.3V, these modules have level shifters so that you can power them from 5V and communicate using 5V logic. All you need is to solder a card holder onto your board since the whole system will be 3.3v.
 
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