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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
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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)
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