Results 1 to 1 of 1

Thread: Making with 'breakout' boards

  1. #1
    Premium Member
    wotnot's Avatar
    Join Date
    Nov 2019
    Location
    Scenic Rim, SE Qld
    Posts
    3,236
    Thanks
    1,462
    Thanked 2,934 Times in 1,510 Posts
    Rep Power
    1334
    Reputation
    58690

    Default Making with 'breakout' boards

    This actually relates back to another thread .

    I decided to pick this little project up, as something to keep me amused enough to lubricate the synapses, but I thought some folks here might appreciate the view.

    Originally slated for an arduino board (which went from nano to atmega1280), it wasn't long before I became disgruntled with a 16Mhz clockspeed, limited progmem, and moved to a different MCU.

    Decided to run with a LOLIN/WEMOS D1 mini MCU, which is built upon the Espressif Systems ESP12-F wifi module ~ they walk all over the arduino/atmel offerings with some ease, but as always, there's pros & cons --- on the plus side, up to an order of 10 faster clock (from 16mhz to 80/160mhz), progmem goes from 256k to 4Mb, and you get wifi builtin, a watchdog, and other interesting facilities including the fact they're cheap as lollies --- on the minus side, you've only get 11 GPIO pins, 1 analog in, no 5vdc level compatibility with peripheral devices, and no builtin EEPROM like the atmels sport.

    Ergo, moving from atmel to esp12-f is a bit of an exercise ~ one has to supplement the EEPROM (if you're using it, and I am), and add extra GPIO to carry user inputs and output driver pins, and I figured the quickest way to do that, was to leverage the I2C bus...(I'm not using analog in, so it's of no concern to me...but if I were, I2C bus ADC chips are out there and plentiful).

    Intent of this thread, is just to demonstrate how I treat one-of projects like this, when it comes to final assembly. Typically speaking, this sort of craft starts out with a breadboard setup, and one can use 'breakout boards' to include other peripheral devices easily and simply. These boards are plenty handy, as they include buffer/de-coupling caps, and all support discretes for the device itself, so I always tend to use them 'as is', and dismiss any idea of getting a PCB made for the task.

    To do that, one needs a really decent prototype board -- I use these from a Qld company ->

    You will never appreciate in words, how good these boards are in practice ~ you really need to buy one, work with it, rework it, deploy it in the field and come back years later, etc etc...to truly know how good these are ; I'm using a medium board for this, with 6.5amp track current rating (as I'm switching up to that amount of 5vdc in one place). The other thing I find appealing with these boards, is you're retaining the same 'formal' of layout, as is used for the breadboard work, and it's easier on the brain in a visual sense -- a lot of the time, you can just think of it as moving from the jumpered/softwired breadboard, to a hardwired/soldered breadboard...in effect.

    So this project board, ended up looking like this ~ yes, I'm a big fan of 0R resistors ;



    Things snowball quickly...needing an EEPROM, I found some TinyRTC modules in a drawer, which have a 24C32 on them, along with a DS1307 RTC, This is actually a 5v board, so I had to squeeze in a level shifter to accommodate it (on bottomside of board) - quick easy way to more GPIO, is a mcp23107 (bottom left), with 16 pins but I'm only using 7. Display backlight mosfets bottom right....to-92 transistor near TX pin of the MCU board, is level booster/driver for ws2812b RGB led strip, and those big fat wire jumps are the switched 5vdc rail for the led strip (which can easily suck 30-odd watts in a worse case scenario) - switching done by ultra low RDS on hexfet bottomside.. (I fixed that solder joint btw =)



    I've hoisted a (currently private) github page for the sketch code (still WIP), which I'll make public once completed...it can actually do a lot more than the original design purpose ...ie; wifi isn't implemented (not required for project), but I took pains to ensure I didn't end up using RX/TX pins as GPIO, which gets in the way of wifi...one just need add the code, and wifi should work without complications.

    More later, thanks for reading

  2. The Following 4 Users Say Thank You to wotnot For This Useful Post:

    ammlione (21-03-21),RFI-EMI-GUY (02-04-21),Rocket (22-03-21),VroomVroom (22-03-21)



Look Here ->

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •