Hi, first post. I noticed the comments in regards the MEGA Rx problems and the maniacbug 1284 bootloader. These may be fixed now, but I thought I'd mention that there have been several *very long* discussions on the Arduino forum re various 1284 problems. It was found that changing the fuse settings to select "full-swing" oscillator fixed the Rx problems. Seems related to cross-talk between the RX0 pin and the adjacent XTAL1 pin.
http://forum.arduino.cc/index.php/topic,146773.msg1102743.html
In short, change the following line in the boards.txt file for the specific variant before burning the bootloader into the chip:
- from: "[variant_name].bootloader.low_fuses=0xFF"
- to: "[variant_name].bootloader.low_fuses=0xF7"
On a side note, just a suggestion ... calling the board "moteino Mega" seems to me conflating it with the Arduino MEGA board, which uses a mega2560 chip. I'd prefer "moteino-1284" myself as more descriptive.
Also, for future updates to various boards, I'd really like to see pads laidout for SMA antenna plugs on every pcb, especially those using the RFM69 radio. Thanks.
EDIT: also, I've been operating the mega1284 with Vcc=3.3V and 16-Mhz xtal for about 1 1/2 years now, and never seen any problems. If you look closely at the graph in the 1284 d/s, you'll see that the specified freq at 3.3V is actually about 13.3 Mhz and not 8-Mhz, so operating at 16-Mhz is only over-clocking by 20%. Works fine. The oscillator problem mentioned above was by far the killer problem with many people.
Thanks for all the thoughts and suggestions.
Yeah I've seen the oscillator issue myself, what a pain...
On the MEGA name ... I can guarantee (at least for the foreseeable future) there will never be a Moteino with a mega2560 chip. I think 1284 is as high as I will go, I have no reason for the 2560, defeats the Moteino ideology.
I can see a real use for the SMA footprint on all the boards. Perhaps Moteino R5 will have one. The MEGA already has it (when it comes out).
And yes I've been running my prototypes at 16mhz 3.3v without issues (after I fixed the others). Fingers Xed for the release...
Still wating for the Moteino Mega, I hope you will release it soon ;)
Will the MEGA have the same low power characteristics as the standard moteino R4, or will it require more power?
Basically it should be just as low power since it's the same "P" technology.
See the 1284P datasheet for accurate specs and what to expect.
When is it suppose to release, Which date ?
Have you checked the blog? It was released last friday Aug 8th!
Impressive! I'll be ordering a couple soon :)
Hello Felix (and other developers),
Awesome, great work! I'm considering to order the R4 USB and new Mega version today.
However, I would like to use my SMA antenna's with the Moteino boards. I see indeed that the new Mega version has pads laidout for SMA antenna plugs. The older R4 USB version lacks those, but is it still possible to solder a SMA connector also on such board?
Furthermore, the SMA connectors (and corresponding antenna's) are not available in your shop at the moment. Could you add these SMA connectors to the product list? I know they are available at many places, but it would be nice to order a full and complete package. Actually, I'm happy to pay more if the boards come with all the pieces mounted (headers, flash, and SMA connector). But I'm not sure if this is possible to order such "deluxe" edition at the moment.
Thanks a lot in advance for your comments, best regards,
RV
Great work with the Moteino MEGA, Felix. I really like the sma/ufl connector solution. I was just thinking the other day that the moteino needed something in that fashion. I noticed you said that the R4 now ships with MCP1703 regulator which allows up to 16V input and i would like to suggest that you add the sma/ufl connector solution and call it the R5. Mostly because someday someone will put 16V on their old R4 which can only handle 9v and thus destroy it.
@RV
I bought these sma connectors:
http://uk.farnell.com/te-connectivity/5-1814832-1/rf-coaxial-sma-straight-jack-50ohm/dp/1248990?Ntt=124-8990
and they fit pretty well on the Moteino R4 as you can see here:
(https://farm6.staticflickr.com/5565/14851927812_094c6d5f44_z.jpg) (https://flic.kr/p/oCq1GU)Moteino 1.75km range test (https://flic.kr/p/oCq1GU) by Felix Rusu, LowPowerLab.com (https://www.flickr.com/people/15304611@N03/), on Flickr
it's a tight fit but if you are carefull with the solder it will work ;)
Looking at your photo, I can see that one of the the SMA connector legs is almost touching one of the flash pad. If it is, it will cause some random misbehavior of the moteino.
Check my post about this issue here: https://lowpowerlab.com/forum/index.php/topic,572.msg3286.html#msg3286 (https://lowpowerlab.com/forum/index.php/topic,572.msg3286.html#msg3286)
Can you tell us where did you source the antenna?
Thank you
Yes i saw your post and checked, they are not touching ;)
I bought these antennas:
http://www.goodluckbuy.com/45mm-433mhz-sma-mini-antenna-for-cc1101-cc1100-nrf905-3pcs.html
They might look good but during testing i soon found out that a straight 1/4 wire gives you about 10-15% more range :)
luisr320, just clip the pin that is near the FLASH chip...if you're really worried.
I will consider these changes for an R5, thanks guys.
@Steinarrr
I'm not sure if the SMA connector you link to is the best option to mount it on a PCB.
There seems to be better alternatives which have better positioned mounting points for the Moteino. For example:
http://uk.farnell.com/emerson-connectivity-johnson/142-0701-801/rf-coaxial-sma-straight-jack-50ohm/dp/1608592
Although this seems like an expensive alternative, you will find similar products for only a few cents when ordered in large quantities from China.
@Felix
It would be awesome if fellow developers could order (the best fitting) SMA mounting connector for their Moteino PCB directly from your shop.
Would this one do?
http://www.tinyosshop.com/index.php?route=product/product&product_id=678
(http://www.tinyosshop.com/image/cache/data/wireless/Antenna/SMA%20female%205PIN-1-228x228.jpg)
luis, I can't tell if they are good, since there are versions for 0.062" PCB thickness and for 0.031" thickness (1.6mm and 0.8mm).
I know the sparkfun ones work well:
https://www.sparkfun.com/products/592 and https://www.sparkfun.com/products/593
If the SMA pins are too long and are worried they will touch the FLASH pins, just clip them with your trusty pliers: http://www.adafruit.com/products/1368
Those from Sparkfun are male and the ones I showed are female. I guess it depends on what type of antenna you order.
Well, the second (593) one of sparkfun seems to be female as well, see the datasheet:
http://www.sparkfun.com/datasheets/Wireless/Antenna/SMA-Connector.pdf
If I'm correct, the datasheet states that the gap between the pins is 1.73mm
However, speaking of adafruit, they offer two female connectors, for both PCB sizes that Felix mentions:
- http://www.adafruit.com/products/1864
- http://www.adafruit.com/products/1865
Which one should be best fitting for the Moteino, is it then the 1.6mm "Thick PCBs" version?
So far all Moteinos came with 1.6mm FR4 PCB thickness.
Thank you very much for the support Felix.
Keep up the good work!
My pleasure sir :)