With 8 IO lines, you have a wide variety of options to control/read. With a simple mod, you can control when the attached battery charges when not plugged into the micro USB. I am so glad that this is now a FAT32 version therefore it can use larger SD cards and I can now easily buy some for in it. It is a very stable board, the programming can throw some people off. I would recommend this Logger to anyone who doesn't have the time or resources to make their own.

The bad: From the description of the product, it hints that the unit can accept serial logging, however, this is only true if you are using TTL level logging. Peripheral MAX232 for RS232 is still needed to talk to PC or other devices that are sending out RS232 data. In this sense, it is not a plug-and-play device. Minimal hardware design is still needed. Improvements needed (IMO)

Add a MAX232 to talk to PC. Improve description to specifically mention that this is only a TTL serial logging device, and additional parts are needed to talk via RS232.

The good: 1) Documentation is spot on! 2) I found new tools to use and debug with. 3) logging and code manipulation is easy. 4) Portability is fantastic. 5) Large data storage card is fantastic and very desirable.

This thing works if you want to log at slow-ish speeds for short periods of time. The sample range is from 2kHz max (for 1 channel I believe) down to 1Hz (which is still too fast in some applications). So this is more of a long-haul type of logger, which makes sense.

But "long" is a loose term here. I've used the thing for some time now and I can't seem to get the logger to last longer than 1.5 days on a 2000mAh LiPo battery logging at the slowest speed. Considering the size of the battery and the sampling frequency, this is pretty abysmal. One of the culprit is a red LED that stays on all the time, but I also suspect the MCU doesn't go to sleep, even when sampling at 1Hz.

I suppose one could depopulate the LED go change the firmware to resolve some of these issues, but I was really hoping to have this work out of the box.

If you're looking to log at a slow-ish speed for a short period of time (e.g. capturing data from a launching rocket), this might be the logger for you. Otherwise, Sparkfun's OpenLog board (https://www.sparkfun.com/products/9530) might be a better fit.

P.S. As an aside, the config file is needlessly confusing and I always end up having to refer back to the hookup guide to help me out.

I got this logger to use for a project I am working on. I started with using it to log analog values and modified the code from there. The information below is related the stock code that comes with the logger.

Pros:

1. Records to SD card
2. Can be run standalone

Cons:

1. buggy firmware (see below)
2. The schematics are poorly written. Several of the labels on the microcontroller pins do not match up with the labels on the connector pins.
3. The code does not have many comments so it takes a while to figure out what is going on before trying to modify the code.
4. The connector labels on the board do not correspond to sequence the analog channels are read in the code

The analog ports are read and recorded in the following sequence:

AD1.3

AD0.3

AD0.2

AD0.1

AD1.2

AD0.4

AD1.7

AD1.6

The board has the following connections

Analog 1 connects to AD0.3

Analog 2 connects to AD0.2

Analog 3 connects to AD0.1

Analog 4 connects to AD0.4

Analog 5 connects to AD1.7

Analog 6 connects to AD1.6

Analog 7 connects to AD1.2

Analog 8 connects to AD1.3

Software bugs and Fixes

.1. The code does not read the frequency from the config file on the SD card right. It will not read a frequency of less than 10 hz from the SD card and does not run at 1 to 9 hz. I changed the program to use a hard coded frequency to run at 1 hz. I changed this line:

“T0MR0 = 58982400 / freq;”

to this

“ freq=1;

T0MR0 = 58982400 / freq;”

.2. The code does not configure the baud rate right at 115200 baud. I suspect some of the other baud rates are also not configured right but I have not checked them. The setting for modes zero and 1 on the logger are:

“U0DLM = 0x00;

U0DLL = 0x20;“

The settings above work out to 117187 baud.

I found this because I was having problems with getting garbage serial data when reading a long string. I changed the baud settings to the ones below and the serial data was read in correctly.

These settings work out to 115215 baud and work better:

“U0DLM = 0x00;

U0DLL = 0x0C;

U0FDR = 0x7C;”

If you see page 151 in section 10.3.5 of the LPC214X manual it has working settings for most of the common baud rates. I found a copy of the manual here: http://www.nxp.com/documents/user_manual/UM10139.pdf

Note that the table in the manual is for a 20mhz clock, and the logger is running at 60mhz so a 3x scale factor is needed

.3. If you are using the second SPI port (the one brought out to connectors, port 0 is used for the SD card) you need to change the program to use the "LPC214x.h" header and register map instead of the "LPC21xx.h" header and register map. In the 2148 processor the “spi” port that is brought out is actually a SSP port and the register map is different. The SSP port can be configured for “Motorola SPI, 4-wire TI SSI, and National Semiconductor Microwire buses”(from the datasheet I linked to above)

note: edited multiple times at first posting to get formatting right

I can save to the SD card 3 signals at a sample rate of 100 hz easily for R&D. Many returned to me where the USB socket had come away from the PCB. I have asked the SparkFun forum for any suggestions

The voltage in pin is labeled "Batt". It is versatile, having both ADC pins and SPI, but both can not be used at the same time. The addition of SPI C++ code examples for the various Arduinos would be very helpful.

Cheap, open source code, nice layout with pads to allow a mezzanine signal conditioning board. love it

For the price, this is a decent device. It does have some weak points though. The microusb connection to the board is flimsy. Don't expect to be able to connect/disconnect more than a few times before it starts to come away. I have connected a short microusb extension cable so that the stress of repeat connects is transferred away from the board. Before that I lost a few boards when it broke away. There should be a breakout for the on-off switch so that it can be operated external to whatever housing you put the board in. Essentially you have to toggle the switch each time you connect to USB, so this needs to be made easier.

Gave the device a bad review but understand that it may have been the voltage from a 2S LiPo. Don't use a 2S LiPo on this board. Will review once again soon. Customer service has been excellent in assisting us with our troubles even though we may have caused the issue.

The data logger was recommended to me by a Sparkfun tech. with the understanding that it would easily connect to a 9DOF sensor stick, however, it does not. The problem is that the sensor transmits with I2C but the logger does not and we could not easily find any open sourced programming to support the two components. We finally ended up buying an Adafruit 9 do that has better supporting programming And we now hove no use for the components we purchased from Sparkfun. I'm sure they work fine but the combination for our use did not work.

Scott N

... because I need to time stamp my analog data but the few existing SW examples are too complicated or not enough documented for me to adapt the firmware by myself !