7. The VDDCore/VDDCap and ENVREG/DISVREG pins must be connected
In addition to some of the other pins, many PIC microcontrollers (particularly the PIC24 and PIC32 product lines) contain pin called VDDCore/VDDCap and ENVREG/DISVREG. These pins are used to enable or disable internal voltage regulators to the core microcontroller logic. Depending on your application, there are a number of possible connections for these pins (Microchip provides a fairly good write-up here), but regardless of your application, these pins should not be left floating.
8. Read the Errata
The good people at Microchip technology work very hard to make low-cost, high-quality microcontrollers. That said, however, production PIC microcontrollers do not always perform to the ideal specification that their datasheets detail. Batches occasionally come off the line in which flaws in the design are discovered later. In these situations, reading the errata before you order your PCB can be a life-saving experience. The errata can be found on the main page for a given microcontroller or device on microchip’s website, and can tip you off to flaws. For an example of what can happen when you don’t read the silicon errata for a microcontroller before moving forward with a design, talk to Dave Jones.
(this video contains some rare footage of Dave getting upset. RARE. srsly.) 😉
9. Do not use an LF part in place of an F part
For most of microchip’s PIC microcontroller product lines, they make 2 variants of a given microcontroller: the PIC18Fxxxxx and the PIC18LFxxxxx. These parts look very similar if you’re scanning a list, but have different functional characteristics. Therefore, it is HIGHLY recommended that you do a quick 2 second check that you have the right part in the shopping cart before you hit that “submit order” button.
[ed. note: the diff. between the “F” and “LF” chips is that “F” chips are designed to run on a nominal 5V supply, while “LF” chips can run at a lower voltage range (say 2-5V)]
Adafruit has had paid day off for voting for our team for years, if you need help getting that going for your organization, let us know – we can share how and why we did this as well as the good results. Here are some resources for voting by mail, voting in person, and some NY resources for our NY based teams as well. If there are additional resources to add, please let us know – adafruit.com/vote
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.