[Youtube] How to make BK7231 development board - NodeMCU conversion - soldering guide, hot air, SMD
Here's a step by step guide showing how to make a BK7231 development board (WB3S and CB3S versions) from a very cheap NodeMCU ESP8266 board, by doing a simple WiFi module transplant. First we desolder ESP12 module with a hot air station, and then we solder a CB3S (or WB3S) in it's place. Our guide includes some basic soldering tips, so even a beginner should be able to do the shown process.
We are aware that there is already some kind of BK7231 development board that can be bought online, but our solution is cheaper and more general. Futhermore, many people already might have a BK7231 module desoldered from IoT device (or may use this opportunity to do a WiFi module swap between NodeMCU and IoT device).
What is required for this project?
- CB3S or WB3S module (you can get that from IoT device, and solder the ESP from the NodeMCU in place)
- hot air station (cheapest one will be enough)
- basic soldering equipment and soldering iron will be also needed, so flux, leaded (Pb) solder, solder wick, PCB cleaner
- NodeMCU board (it can be bought very cheaply online, it's available in many shops)
Here's the guide:
[youtube]
https://www.youtube.com/watch?v=xGE-DVrm3BU
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In addition, we're including a new pin mappings for a BK7231 board created that way.
Warning: CB3S has slightly different pinout than WB3S, both pinout versions are included on the guide below:
Here is NodeMCU schematic:
Dev board in action:
Thank you for watching. Please consider giving us a like and/or subscribe.
You can also visit out BK7231 firmware page:
https://github.com/openshwprojects/OpenBK7231T_App
our BK7231 flash tool:
https://github.com/openshwprojects/BK7231GUIFlashTool
and our IoT devices teardowns list:
https://openbekeniot.github.io/webapp/devicesList.html
Have fun tinkering and stay free from the cloud!
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Comments
Add a commentOn ali you can buy an inexpensive board that has everything except the ESP system. It makes no sense to destroy NodeMCU. https://obrazki.elektroda.pl/4600075100_1682156051_bigthumb.jpg [Read more]
Great idea! I was not aware that there is a relatively cheap board for this pad format and without a soldered module, although in retrospect it seems obvious. However, I would not be afraid of the "destruction"... [Read more]
Conversion is done and ready to test on a new driver :) https://obrazki.elektroda.pl/3771210400_1682334954_thumb.jpg [Read more]
Good job with conversion. Which soldering station did you use? Btw, from a brief glance, it looks like the TM1638 on your photo may be very similar to gn6932 and also to TM1637. We'll see how it go... [Read more]
From 1.17.53 build, you can switch logging UART via the example below: // Enable "[UART] Enable UART command line" // this also can be done in flags, enable command line on UART1... [Read more]
Yes, setting UART1 as log port (instead of UART2) will help on this board a lot, because UART1 has the CH340 hooked up (and is also used for programming), while, on the other hand, the default UART2 would... [Read more]
Worth pointing out default speed is 115200 for UART1. [Read more]
my work in progress https://obrazki.elektroda.pl/5351507900_1710970973_thumb.jpg I've butchered this device for its CB3S https://www.elektroda.com/rtvforum/viewtopic.php?p=20904497 I kind... [Read more]
Heat gun is there a must have. Maybe you could try to use a high power soldering iron and form a U shape with a thick wire that will heat all pads at once but I am not sure if it will have enough heating... [Read more]
Very interesting idea! Or I have two soldering irons, one is old and in my recycling bag, but it could be brought back to life for some double-iron multi sided action. Added after 8 [hours] 11 [minutes]:... [Read more]
It didn't go too badly. Fairly smooth until the very end. The bent soldering iron to cover two corners wasn't a success - the original tip was too fat and the bend too curved to be effective. Nails and... [Read more]
decent outcome. all of the normal/standard GPIOs work fine. assume a couple are default pull-high because the LEDs come on as soon as the board is powered. one LED is duller than the rest - S3/P20/SCK... [Read more]
That's an interesting finding. I'd first double check, maybe there is an extra resistor on the board or something. Also I'd just swap in place two of the LEDs just to be sure it's not a faulty LED. You... [Read more]
yes. these are cool https://obrazki.elektroda.pl/9185680000_1713337370_thumb.jpg [Read more]
So, do they work good for BK7231? How do you do power cycle there - CEN? [Read more]
i've not got a BK module loose to try, but it has a reset button (bottom right in my pic) the same as other dev boards. I have started flash dump in Easy Flasher using this button. I've only tested RX/TX... [Read more]
can someone please check continuity from P20 on the CB3S to S3 on the nodeMCU if they've done the transplant. mine maps to SK pin not S3 as shown on the diagram in first post https://obrazki.elektroda.pl/3106518700_1714423248_thumb.jpg... [Read more]
@divadiow S3 -> P21 SC -> P23 SK -> P20 [Read more]
thanks! grr wish I'd double-checked diagram was correct ages ago. [Read more]