Recent Posts

1

Beginners / Re: Convert US standard 115V to International 230V

« Last post by Jwillis on Today at 08:06:17 am »

Just to clarify, North American standard household voltage to both 120V and 240V @ 60Hz. Being split phase.

2

Test Equipment / Re: Hacking the Rigol DHO800/900 Scope

« Last post by RAPo on Today at 08:05:59 am »

I would move the math-button next to the channel-buttons., so that one large black area comes free where the time info can be placed (starting a bit like a siglent ;-)).

3

Test Equipment / Re: Hacking the Rigol DHO800/900 Scope

« Last post by shapirus on Today at 08:05:39 am »

that's impressive indeed.

don't stop :)

4

Test Equipment / Re: Hacking the Rigol DHO800/900 Scope

« Last post by mrisco on Today at 08:05:12 am »

Have you switched somehow between full screen mode and normal mode while working? Or is it a separate full-screen version of the application?

It is the same application compiled with some changes as a proof of concept.

5

Microcontrollers / How to create custom bootloader in esp8266

« Last post by digitalectron on Today at 08:05:05 am »

Hello EEVblog community!

I am currently working on a project with ESP8266 and I want to write an OTA bootloader for it. This bootloader should run when the microcontroller is reset and, based on user selection, either enter programming mode to upload a new main application, or run the previously uploaded application.

I have not worked with linker scripts before, so I am looking for a simple example that includes two programs:

Bootloader program: This program should remain constant and perform the following tasks:
Detect whether the user has pressed a button to enter programming mode.
If the button is pressed, go to programming mode.
If the button is not pressed, run the main application that is already stored in flash memory.
Main application: This could be a simple program like an LED blinker program.
I would appreciate any help you can provide on writing this bootloader and how to use linker scripts to achieve this goal.

Additional details:

I am using an ESP8266-12E.
I want to use the platform IO for development.
Questions:

How can I write a bootloader program that runs when the microcontroller is reset?
How can I use linker scripts to select which program (bootloader or main application) should run?
What is a simple example of how to use linker scripts to achieve this goal?
Thanks for your time!

6

Test Equipment / Re: Hacking the Rigol DHO800/900 Scope

« Last post by mrisco on Today at 08:02:17 am »

New header bar

7

Projects, Designs, and Technical Stuff / Re: Connectors for Breadboard and PCB: GPS module EM-506

« Last post by Solder_Junkie on Today at 07:59:43 am »

 You can buy kits of those type of connectors from eBay and Amazon, measure the pin spacing to make sure they are the same. Crimping tiny connectors is challenging though, I have damaged quite a few pins when crimping and now use a mixture of solder and crimp tool...

In my GPSDO projects, I have used GPS boards which include a micro USB socket. It makes testing/configuring much easier.

SJ

8

Test Equipment / Re: Hacking the Rigol DHO800/900 Scope

« Last post by AndyBig on Today at 07:57:14 am »

Or maybe they don't care. Who is brave enough to run the experiment? 

Two months ago I gave here a link to my github

If you want more space for waves, you can use full screen mode. 
I have taken a picture of the oscilloscope and not a capture so that you can see that it is not a clipping.

Have you switched somehow between full screen mode and normal mode while working? Or is it a separate full-screen version of the application?

9

Test Equipment / Re: Hacking the Rigol DHO800/900 Scope

« Last post by mrisco on Today at 07:56:34 am »

If they used GPL code, then they must release the source code of the entire project, and can't restrict the use of the code.

10

Beginners / Re: New multimeter, is the thermometer good or better standalone?

« Last post by Solder_Junkie on Today at 07:52:35 am »

Thank you for all your answers, I bought the UT890D+, a bit cheaper than the UT89XD with no big diferences, and will bout the TM-902C or something similar later.

Beware the UT890D+ doesn't meet any kind of safety standards, a 5×20mm glass fuse (which they appear to use from the user manual) is not safe in high Voltage/current circuits, not even on mains Voltage.

For not much more money you could have bought a Brymen meter, which is certified by the US Underwriters Lab (UL listed) and as recommended (and sold) by Dave Jones (Mr EEV).

This is from the BM235 user manual, I have one of these meters:

Safety: Certified per IEC/UL/EN61010-1 Ed. 3.0, IEC/UL/EN61010-2-030 Ed. 1.0,
IEC/UL/EN61010-2-033 Ed. 1.0, IEC/UL/EN61010-031 Ed. 1.1 and the corresponding
CAN/CSA-C22.2 regulations to Measurement Categories:
CAT II 1000V, CAT III 600V and CAT IV 300V AC & DC

SJ