Is it also safe to use on the top of the board?

Isopropyl alcohol is used for cleaning flux residue after soldering. It is safe to use on top of the board.

Is 91% good enough?

Isopropyl alcohol is usually specified as 99.x% and not 100% because it is hygroscopic. I think it's best to get the "100%" kind. With a 91% solution, the other 9% might not evaporate and leave residue instead.

The standard solvent used for cleaning PCB is 100% (or close to it) isopropyl alcohol.

But what you think about this one? http://www.dealextre...ls.dx/sku.36153

For the price difference, I'd go with the Rigol. It's better value.

I was thinking to buy this one http://www.saleae.com/logic/features/. Is it good enough?

It seems like a really nice package. I've just tried out their software.The user interface is clean and easy to use.
Many comments on sparkfun product page (http://www.sparkfun....roducts_id=8938) are very positive.

Any suggestions? I'm looking for something small, and easy to move around since I do my work in various parts of the house where I can get some space. :-)

If you can afford it, I suggest the Rigol DS1052E. It has the bandwidth and sampling rate needed for most microcontroller project. The sampling rate for the DSO nano is often too slow

If you are just going to look at digital signals, you can consider USB logic analyzer. There are a few companies that makes them.

Are you having data communication isssues on SPI because of this?

I have not tried connecting the SPI to a device yet. I think the extra clock edge will cause communication issues for devices that do not have the Chip Select line connected.

Regarding clock speed, when I try 1000 Khz, I see 550.66 Khz on my oscilloscope ...

It seems that there is minimum SPI clock speed of about 200KHz.

Desired setting -> Frequency measured on oscilloscope
6000kHz -> 6.00MHz
1000kHz -> 1.00MHz
300kHz -> 300kHz
150kHz -> 743kHz
100kHz -> 215kHz
10kHz -> 251kHz

Currently I use a clock at 1000 kHz with my nokia 3310 LCD with success,

Thanks Pascal,

My problem is that the hardware generates clock at a rate other than specified.

Hello,

I'm trying to figure out SPI on the netduino with this code:

using System;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.Netduino;
using System.IO.Ports;

namespace NetduinoApplication1 {
    public class Program {
        public static void Main() {
            SPI spi_port = new SPI(new SPI.Configuration(
                Pins.GPIO_NONE,                             // Chip select pin
                false,                                      // false - CS active state is low
                0,                                          // CS setup time in ms
                0,                                          // CS hold time
                false,                                      // false - Clk low on idle
                false,                                      // false - Data valid on falling edge
                100,                                        // Clock rate in kHz
                SPI_Devices.SPI1                            // SPI Module
                ));
            byte[] readBuffer = new byte[2];
            while (true) {                
                spi_port.WriteRead(new byte[] { 0x00, 0x55 }, readBuffer);
                //Thread.Sleep(1);
            }
        }       
    }
}

I have problem with:
1. Clock rate adjustment. What clock speed is supported by Netduino?
2. 20us before the data transfer, the clock line is weakly pulled-up for about 40us. This gave me an extra unwanted clock edge. Is it possible to remove this?