Is there any real point to a custom made uC dev board? - Page 1
Forum section: electronics / projects

author: Buriedcode
author_rank: Super Contributor
timestamp: January 16, 2016, 03:46:17 pm
content: Hi,Been a lurker for a while, first post, so not sure if this is the correct thread.About 8 years ago (gawd, just before the arduino made it big) I toyed with the idea of making my own dev board, one for PIC's (16/18F, 8/14/28/30 pins) and one for AVRs (specifically the megas). As I tend to over complicated things what once was a relatively simple breakout with power/RS232/programming had ballooned into what could be thought of as a eurocard sized 'EasyPic7'.I had the idea of a stacking connector (2x20), 10-pin headers for each port, break outs specific to comms, and analogue section with opamps (selectable gain), and many jumper settings for routing IO's that have multiple functions.It seems over the years the sheer number of boards, modules, and oh-so cheap 'add-on boards' has rendering this idea obsolete. Of course, many make their own dev boards, that are biased towards ones own types of project. Even only 10 years ago there were many boards available, most of which were made by the chip manufacturer themselves.My question is, does anyone actually use their own custom dev board? or have they found the modular approach of arduino-style boards much easier/cheaper? I ask because for just tinkering most boards are fine, but when it comes to 'alpha-stage' prototyping, I end up having to do a lot of quick'n'dirty 'SMD on stripboard' adapters, and wiring, that slows the process down significantly. I realise there isn't much point in making yet another open-source devboard in an already saturated market, so it wouldn't be for financial gain, purely for practical purposes.BC

author: KL27x
author_rank: Super Contributor
timestamp: January 16, 2016, 08:48:04 pm
content: QuoteI have sometimes not even used the manufacturer demo boards which I paid for. Often it is easier to fab something specific to a purpose. The price of PCB manufacture is so cheap and easy. These days ordering from china is the same as ordering from Amazon. No mandarin necessary.

author: nctnico
author_rank: Super Contributor
timestamp: January 16, 2016, 09:08:33 pm
content: Quote from: Buriedcode on January 16, 2016, 03:46:17 pmI have several. Often as part of some kind of tinkering project. Instead of headers I use tiny pads to which I solder thin enamel wires.

author: ajb
author_rank: Super Contributor
timestamp: January 17, 2016, 01:20:46 am
content: I've made a few bare-bones dev boards. For small mcu projects I generally only want the bare necessities on the board itself--crystal(s), decoupling, LDO, USB connector if applicable, and a couple of LEDs--which can usually be fit in a dual in line form factor that will fit into a breadboard, or can be installed onto perfboard for little one-off projects. Obviously if your project involves external memory or Ethernet or something you'd want to put that on the board with the mcu, but for that sort of project a ready-made dev board that already has those things, if one is available, is a better use of time and money than rolling your own.

author: AlxDroidDev
author_rank: Frequent Contributor
timestamp: January 17, 2016, 02:20:23 am
content: I have over 20 dev boards: 10+ Arduinos, MSP430, MSP432, STM32 M3 in several styles, ESP8266, and the list goes on.The board that I use the most is a homemade UNO clone. I've also had 3 Atmega328-based boards custom built (etched at home) because of specific projects: they had to meet specific size and pinout requirements.In other projects, I'll just buy an Arduino Pro Mini and connect it to the board.

author: Buriedcode
author_rank: Super Contributor
timestamp: January 17, 2016, 04:41:48 pm
content: Thanks for the replies lads,It really does seem we've become fairly spoiled with cheap dev kits for hobbyists these past few yeahs eh? Just picked up a lattice MachXO2 board for £20... and I will probably never push that devices capabilities. I still have plenty of custom small 'breadboarding boards' that were made only a few years ago but already pretty much obsolete, as well as various boards from the small companies that come and go (MDfly?).I guess I'm not alone in have many many smaller boards, rather than just one 'big board per mcu manufacturer'. Does anyone create proof-of-concept on stripboard anymore?

author: Kilrah
author_rank: Unknown
timestamp: January 17, 2016, 05:16:42 pm
content: Not much point IMO... Manufacturer or 3rd party dev boards are good enough to get used to "manipulating" the desired chip and validating toolset workflows (basically making sure I can write/build/flash a program that can flash a LED, talk over serial and other simple stuff, maybe some basic interfacing to other components of the project if they aren't too much of a pain to wire... then it's time to think about making version 0.1 of the PCB for the specific project at hand. Put everything you want how you need it , might not even have everything the project needs at this point but at least you've got something convenient to work with, and it'll serve to validate that part of the PCB design as well (or allow you to detect issues you can correct before moving further in complexity).

author: Simon
author_rank: Unknown
timestamp: January 17, 2016, 05:23:07 pm
content: I don't really see the point of them really as you often have to learn all about the board first rather than just build what you need. I think on the one hand they are good for office only based programmers that can't make their own up and jut need to program something or for people who need to look good because writing code is all they can do. A quite visit to the arduino forum will show how electronically illiterate many people claiming to do electronics are.I tend to make test boards for whatever i need. Right now I need to learn about ISP busses and CAN bus as it's my next logical step. So I started to make a veroboard project with 2 ATMega328's and two MCP2515's so that I can start playing with the ISP bus and then the CAN bus when I'm ready, any off the shelf boards do that ? and If i had KiCAD setup which I'm in the middle of doing I could have bashed a PCB out and had my own dev board to look good with.

author: Kjelt
author_rank: Super Contributor
timestamp: January 17, 2016, 09:45:04 pm
content: Not as much dev boards but for each project i design my own boards usually just one of a kinds not series stuff. I often use a stm8 and there ain,t many general dev boards except huge overcomplicated stuff with tons of extras. For the Stm32 i use the standard dev boards though don,t need that many of them and they cover what i need.

author: bson
author_rank: Unknown
timestamp: January 17, 2016, 10:44:13 pm
content: Quote from: Buriedcode on January 16, 2016, 03:46:17 pmBoth my own and off-the-shelf. Often off-the-shelf boards just aren't suited for a particular application. They may not have the right high-speed peripherals, or are too power hungry, or too big. Or that use weird-ass high-density connectors to fit 200 signal lines when you really only need 4 and would like them on SMA connectors as HS pairs. Sometimes when picking up a new uC/DSP family it can be worthwhile to make a small board with just some leds, a couple of token peripherals, along with I2C, SPI and JTAG/SWD headers to familiarize oneself with the pinout and electrical behavior of the family. This gets the basics out of the way so when you make a more complex application specific board you don't mess it up by say misinterpreting how the programming header should be connected.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 18, 2016, 04:33:04 am
content: Sure, I've made one for a company before. The usual purpose is testing a specific combination of hardware (say, MCU, display, buttons, comms, IOs...), while keeping it general enough (lots of test points, headers) that other devices and variations can be tried.But not so general as a traditional dev kit with headers and riser boards for anything imaginable.It's kind of an expensive way to do development though (design and prototype of a basic board is around $10k parts and labor).If it's all your own time and money, you're probably as well off, either way.Tim

author: westfw
author_rank: Super Contributor
timestamp: January 18, 2016, 07:30:40 am
content: QuoteYes. Not to mention the ones that have REALLY cheap Chinese versions - I designed a nice minimal arduino-like board (RBBB clone) that theoretically might have been useful, except that pro-mini clones from china are cheaper than I could get parts.The other thing that has changed is that the cost to do a "full custom" PCB has gotten a lot lower, so if I DO do a "custom" board, it's likely to be targeted to a specific purpose rather than be made into a general "development board"...

author: tszaboo
author_rank: Super Contributor
timestamp: January 18, 2016, 01:36:28 pm
content: Not really demo boards, more of prototype 1 or proof-of-concept boards. Those are rushed, not fully functional, not mechanically final boards, which have the MCU to kickstart the development (because firmware programmers do absolutely nothing unless you give them boards) and test parts of the remaning circuit. For example, if you have an 32 channel DAQ, you build the first 4 channel with different frontend, two different type of reference voltage...I personally dont think there is a need to "test microcontrollers". They are most of the time the easiest to get right the first time.

author: TheDirty
author_rank: Frequent Contributor
timestamp: January 18, 2016, 07:43:25 pm
content: Quote from: ajb on January 17, 2016, 01:20:46 amThis for me also. I will make up a bare bones board, but mine are usually single inline. I'll make up little modules for sensors, display, controllers, or other chip interfaces. Only thing that's changed for me is now these little chip modules are super cheap from e-bay/Ali, often cheaper than buying the separate chips.

author: Buriedcode
author_rank: Super Contributor
timestamp: January 20, 2016, 02:47:30 pm
content: Thanks for the replies lads!I have dug out a box of all the 'helper modules' I made over the years, hoping to put some to good use (many are a bit too specific for general purpose 'tinkering'). Its a shame the industry has moved on so fast, its amazing just how 'old' something can appear, even after a few years. I'm sure things like Xilinx 9500XL CPLD's are still used, but there are far cheaper/better/newer programmable logic about - and boards with built in configuration hardware - but for hobbyist projects I've held onto them.Nandblog, agreed. I don't think I have ever designed/used an 'evaluation' board for uC's, just dev boards. Although one could argue that boards for other devices like switched-mode-PSU, the boards would probably be classed as 'evaluation'.I asked the forum about this because, whilst I have had contracts for electronics hardware design, I found I never really used dev kits. I suspect that is because said projects were fairly simple and I used subcircuits/micro's that I had used before and trusted. I wasn't sure if the industry still knocked up crude (breadboard/stripboard, hell, even point-to-point wiring) test hardware, or whether it was now just the hobby domain?The prototypes (alpha) I made never looked 'professional', and I suspect some customers were not overly enthusiastic with the approach (managers and sales people mostly) but it did speed up development from weeks to days. I fear I am out of touch, since I haven't done hardware jobs for a few years now (been mostly software), and I am hoping to get a new job as a full-time hardware design engineer - so thought you guys could give pointers on more professional ways to develop.Cheers!

author: bxh
author_rank: Contributor
timestamp: January 20, 2016, 03:16:53 pm
content: I made a bunch of dev board for a few AVR and ARM MCUs a couple of years back, and they're my go to tools just because of how familiar I am with them. They're designed to be minimal, mounted semi-permanently on a breadboard and take as little space as possible and give me full access to pins, programming and debugging headers. For some reason, I just didn't find that combination of features at the time.

author: Buriedcode
author_rank: Super Contributor
timestamp: January 20, 2016, 04:06:20 pm
content: Examples of various modules. Some got a lot of use, others took hours and hours to make, but only got used for 5 minutes... the AVR/PIC header boards with crystal sockets/programming headers are invaluable.

author: rsee
author_rank: Contributor
timestamp: January 22, 2016, 03:15:51 am
content: When I've done projects, I've always went with building it up myself. I had PIC dev kits or MSP430s laying around and those were fine for getting a feel for the tools they provide, but it was just easier to build up a small prototype. I will say, that was for work so I'd usually send it to our board house to have them put the parts on. Soldering for me comes down to one simple rule, "Bigger blob, better job."For building your own, you get a deeper insight into the design and can build more stuff into it. Knowing where your signal layers were routed and where there might be cross-talk or whatever is important when it comes to debugging. For really sensitive control applications, jumper wires pick up too much noise and will only cause problems.I guess bottom line is, it depends on what you are doing. IMO, there will always be value if it is your own design.