DIY RAMPS 1.4 SD

I'm having a problem where Pronterface takes long pauses in sending commands to the Arduino Mega. One method for solving this problem is to print from an SD card. It also gives me the option of using my laptop elsewhere. I want to use this kit from sparkfun because i can source it locally. It also supports SPI.



Problem is the SD ramps on the reprap wiki doesn't have a schematic diagram.

here's the parts list:
PCB SD RAMPS PCB PCB
C1 2.2uF Tantalum 1206 Capacitor
IC1 74HC4050 Level inverter
IC2 MIC5209-3.3YS Voltage regulator
LED1 LED1206 red LED
R1 1kOhm 1206 Resistor
SV1/SV2 6x2 stackable header Header
U$1 MicroSD socket

The sparkfun kit only includes the microsd socket.

Pinout is:

1. CS
2. DI
3. Vcc
4. SCK
5. GND
6. D0
7. CD2

Arduino Mega 2560 pins:

#define SDPOWER -1
#define SDSS 53

Has anyone done this before?

Can someone provide me with a schematic diagram?

I'm using an ATX PS that has a 3.3V output so the voltage regulator could be omitted.

Is the level inverter necessary or can i just use a jumper cable to rearrange the pinout?

Schematics should be here:
[koti.kapsi.fi]

Thanks!

Here's the file for anyone else that wants it.

The SD card is probably useful anyway, but I think something is wrong with your serial setup if pronterface is giving long delays. Have you tried typing gcode directly into a serial terminal to see if the mega is responding correctly?

@lincomatic2: I can make prints, firmware is responding perfectly. Only issues are 3-4 times a print (3 hours) it takes a pause of 5-15 seconds and leaves a blob. I used pronsole to send gcodes and noticed that that pauses occur when you are monitoring the printer and it generates the % completed.

On top of that, occasionally / randomly communication just ceases. It wrecks the print mid way through. The heatbed and extruder temps are maintained so i know the firmware is still running. Pronterface must be the problem, I need to close it and re-open to re-establish a connection with the printer.

Printing from the SD should solve both these problems and free up my laptop to do other things. (Slice stuff!)

Things i've tried:
switch from sprinter to marlin - still pauses and disconnects
send from pronsole - less frequent pauses when not monitoring, still disconnects
try different baud rates - still pauses and disconnects
add ferrite cores to the USB cable - still unknown

things i haven't tried:
using slic3r - shouldn't make any difference
teacup, replicatorG, other GUIs - let me know if one solves this problem
powered usb hub - apparently has something to do with ground differentials and crappy PSUs

Hmm.. seems like you've done your homework.
Here are some ideas:
1) try connecting directly to the computer (no external hubs)
2) try downloading and installing the latest driver directly from FTDI
3) turn off your power management. I've seen some computers will power down the USB if the computer idles too long
4) try a non Python-based gcode sender such as repsnapper or replicatorg
Good luck!

Hi, aplavins!

I'm having similar mid-print communication ceasations with RAMPS 1.4 and repetier-host 0.4 on mac 10.7.4 with my Prusa.
I've tried changing the USB cable, I've added a fan to the heatsinks, and I've updated the firmware.
Have you had any luck adding the SD card to your machine? I'm very interested in a solution.
Thanks!

Haven't done an SD print yet, I found the problem though. It was my laptop I was printing from, I switched from my new HP laptop to an old dell and no more comm errors.

I'm just finalizing my automated start gcode, then I'll be able to print from SD unattended.

Huh. I've got a new macbook pro. What was wrong with your laptop?

Not an expert in that department but someone told me that it has something to do with the way it sends serial commands over USB.

Hi, what format is that schematic in? I tried KiCad, it doesn't open. I am trying to make a full size SD reader for ramps.

It is Eagle format. There is an Eagle Light version [www.cadsoftusa.com] which can be used to view any Eagle schematic/board.