Best way to reduce an Arduino board down to what I really need - Page 1
Forum section: electronics / beginners

author: jmashburn
author_rank: Contributor
timestamp: May 14, 2014, 04:41:04 am
content: I wrote some desktop software in Python.I tested circuits with Arduino / Breadboard.Then I packaged up the Arduino board w/o breadboard into an encasement for better testing.I like what I have setup so far and now want to move forward; figuring out the manufacturing requirements for the circuit. An Arduino Uno was used in the prototype, but I'm quite sure I don't need all of the extra features it offers.My prototype communicates with Python via USB Serial and uses a pretty simple button / LED indicator setup, and that's basically it. It powers itself from the USB (no batteries). What I want to do now is learn the best way to reduce down what I have built into the parts I actually need (as per manufacturing my own boards specifically for this purpose).I watched the manufacturing video on here, which was fantastic! I'm aware of the pricing involved and will probably be looking to do a short run of ~5,000 after it's tested.Anyway, question time:I have this working prototype. I need to clean up my manufacturing projections and want to find the most inexpensive parts required to do the job (5k, 10k, 100k orders). What direction should I be walking in?Is this a forum where I could ask people to help?Should I hire someone? (seems like such a relatively small job to do)Are there articles or software that will help tell me what parts I should look for?Requirements (just incase):USB serial communication / powerNo internal storageSimple button that reports on/off (or maybe soft potentiometer)LED (for indicating state)Thanks guys and gals!

author: sleemanj
author_rank: Super Contributor
timestamp: May 14, 2014, 05:09:24 am
content: Arduino Pro Mini (compatibles) are about $3 USD/each on eBay, and are not really much larger than a DIP chip.Even if you don't use the Arduino environment/bootloader, rolling a raw ATMega into your own design at this point, is more about doing-it-for-the-sake-of-doing-it than about being productive probably :/

author: psycho0815
author_rank: Regular Contributor
timestamp: May 14, 2014, 11:06:04 am
content: The Arduino Pro Mini does not have an usb-port. So you would still need some sort of uart-to-usb chip and needed peripherals. depending on what exactly your gadget is doing, the cheapest way might be to use a attiny2313 and the v-usb software stack. Or go with an usb-enabled mcu like an atmega 8u4. Of course that would require you to port your arduino code to avr-gcc. How hard that's going to be and what mcu is suitable for you obviously depends on what exactly it is you're doing.Hardware-wise i'd say the attiny-way should work. Memory might be an issue though.If you use an atmega 32u4 you get built-in usb and arduino-compatibility. Not sure how much that one cost in quantities.

author: retrolefty
author_rank: Super Contributor
timestamp: May 14, 2014, 01:35:48 pm
content: As other have implied, due to the popularity of the arduino platform, it's hard to actually design and build a basic functional arduino module cheaper and quicker then just buying one of those Asian E-bay 'clone' models. Unless you just want to gain the knowledge and experience of building it yourself your better off buying a low cost module and get on with the creating the code and external circuitry needed to accomplish your project goals.Because you want PC serial capability you are better off with a arduino Nano module for around $7-8. It includes a FTDI USB serial converter chip and a full off AVR 328P micro. So it will run any code the standard arduino Uno board can in a much smaller footprint.http://www.ebay.com/itm/PL2303-Nano-V3-0-ATmega328P-5V-Micro-controller-Board-For-Arduino-compatible-/181242945522?pt=LH_DefaultDomain_0&hash=item2a32ebdff2

author: Jeroen3
author_rank: Super Contributor
timestamp: May 14, 2014, 02:36:12 pm
content: Buy some FT230X chips and some lqfp Arduino compatible atmega chips similar to yours.Put it on a board in a nice box with some caps, protection diodes and a power supply. Maybe one of those fancy 78xx pin-compatible switching supplies if USB isn't your only supply.Don't go for any custom USB attiny solution, they are not plug&play. Other solutions require drivers which will require support and maintenance.

author: jmashburn
author_rank: Contributor
timestamp: May 14, 2014, 04:37:27 pm
content: I'm not purposely tied to Arduino for one reason or another.. it was just good to test with. However, I do need the communication layer between the circuit and the PC.The Nano v3.0ATMega on eBay was pretty interesting, but is that something I could go to full manufacturing with to eventually produce 100k units or would I be better off getting the raw parts? That's the point I want to be scoping out for.Thanks very much for the replies guys! I'm still digesting the responses so far.

author: idpromnut
author_rank: Unknown
timestamp: May 14, 2014, 06:51:54 pm
content: The best advice would probably be to start off by watching Dave's Design for Manufacturing videos (he has 2-3) plus the videos he did showing the work involved with re-tooling his uCurrent design for larger scale manufacturing. There are a lot of good nuggets of info in those videos, especially for newbies like myselfHowever, even if I am not doing this type of work, I would say that for 100k units, you should probably be looking at getting at least the advice from a seasoned engineer that has done this type of tooling for manufacturing work before. Their experience will be well worth what you will pay.

author: djococaud
author_rank: Regular Contributor
timestamp: May 16, 2014, 06:45:03 am
content: You can buy leonardo micro, that have a micro-USB connector (and it's not as big...)http://www.ebay.com/bhp/arduino-leonardo-microorhttp://www.ebay.com/itm/2PCS-Mini-USB-Nano-V4-0-3-0-mega328-5V-16M-Micro-controller-board-For-Arduino-/400697632806The button is hooked to reset, but you can use it as standard IO (PC6 on Atmega328).

author: jmashburn
author_rank: Contributor
timestamp: May 17, 2014, 07:41:49 pm
content: @stonent Oh wow, did you just make that or was that already floating around the internet?Regarding people saying buy a Leonard Micro or Arduino Pro Mini, etc.. That looks like it'd be good for like 100-500 orders or so, but would that still be the most efficient solution for producing 10,000 or 100,000 units?

author: Skimask
author_rank: Super Contributor
timestamp: May 17, 2014, 09:32:27 pm
content: Seen the Trinket over at Adafruit?

author: jmashburn
author_rank: Contributor
timestamp: May 17, 2014, 10:00:09 pm
content: I have not but I have now! That looks pretty nice! Have you tried it before?

author: Hideki
author_rank: Frequent Contributor
timestamp: May 17, 2014, 10:12:28 pm
content: Trinket doesn't give you serial over USB. You could perhaps run V-USB and the AVR-CDC code on the ATtiny to give you CDC, but it's not exactly a reliable way of doing things. Very cheap if you can get it up and running though.FTDI's FT230X or something similar will at least give you a proper USB serial port with decent drivers (unlike the windows cdc drivers). That combined with your choice of cheap-ass microcontroller should do it.Can it run Arduino code? Depending on the choice of MCU, it probably could, but it doesn't sound like it needs to do that.

author: jmashburn
author_rank: Contributor
timestamp: May 18, 2014, 01:54:08 am
content: Hideki, good point. I just found that out after researching it a bit. It doesn't work on Linux, doesn't have serial communication, and only works on USB 2.0 and lower. I may have to try something else, even though everything else about it is so enticing.

author: Stonent
author_rank: Super Contributor
timestamp: May 19, 2014, 11:16:06 pm
content: Quote from: jmashburn on May 17, 2014, 07:41:49 pmNo but I remembered seeing it before.Here's another option:http://www.dfrobot.com/index.php?route=product/product&filter_name=beetle&product_id=1075

author: Dave
author_rank: Super Contributor
timestamp: May 20, 2014, 12:34:57 am
content: Why do you even need an arduino? Any FTDI chip you pick has CBUS pins which could easily be used for reading the button and switching an LED.Keep it simple, mate.

author: marshallh
author_rank: Unknown
timestamp: May 20, 2014, 01:06:55 am
content: If you are actually going to ship 100k units then I would approach Holtek and get product information from them for a 8051 USB mcu or something similar. They are the cheapest thing around, but don't expect to get the light of day unless you're a volume customer.

author: jmashburn
author_rank: Contributor
timestamp: May 20, 2014, 02:16:27 am
content: @stonent That Beetle looks great! I'm definitely going to try that and see how it performs. Thanks for finding that man.@Dave I just happened to have an Arduino around so I used that to prototype with. Your point is quite right though and what I'm trying to answer in this thread. I ended up creating a very simple prototype that needs to be reduced down.. whether it requires Arduino or not doesn't really matter. It's more about figuring out how to reduce everything down to the essentials and at the lowest practical cost.@marshallh Thanks for the advice, I'll keep them in mind. We're obviously not doing 100k right off the bat, but we want to put together rough cost projections. Our market definitely supports that kind of volume. Even with 5% market share, there are more than 4MM possible customers. I want to make sure that we don't put ourselves in a bind if, for some reason, sales were to really take off and we couldn't keep up it.