Messages posted by: Rick

Greetings,

We just started using the winbond memory and am in the process of lowering costs of the miniwireless about $2 each.
Also, we will be updating our website store to reflect these changes, but a little busy now over the holiday season.

Here's the spec for the memory:
WinBond Memory Datasheet

Prior to this, we used the spansion flash memory. The manufacturer has raised prices on these, and there is significant lead time, so this is the main reason why we are phasing in the winbond smaller memory.
The good news, is this greatly improves compatibility with similar products which support wireless programming (such as in the moteino product line).

Here's the datasheet for the LoRa RFM95W

Greetings,

Yes, the etch for VBAT (Pin 3) on the RTC runs under the chip, so it is not practical to try and cut the etch. The best way is to unsolder and lift the VBAT pin and wire directly to the lifted pin.
Hopefully it is easily doable for you, but let us know how things work out. Thanks.

Best Regards,
-Rick

Hi Jeremie,

Thanks for your post.
Yes, 1mA is way too much. What did you find upon changing to VIN instead of VCC?
Seems like the LDO regulator might play a roll in that affect

Thanks also for your feedback, as you're right, we certainly need to do some updates.

That resistor was excluded from the assembly profile, so it should no longer be present on current builds.
(I will check to verify this is being done properly).

Also, please look at the Memory register settings and usage for: Active, Standby, and Deep Power-Down Modes.
It seems to me you are already looking into MCU settings, but memory settings are also an important consideration.

Very interested to hear more of your progress and findings.
Best Regards,
Rick

Reprogramming and rebootloading these should not be an issue. Older units had possible SPI contention due to floating chip select on the RFM radio, but we have long since added a pullup on that.
It does not make sense that you are having this issue, but I would like to try to duplicate the issue.
Please send me a private message so we can arrange, and the results we can post here for the benefit of all.
Thank you.
Best Regards,
Rick

Yes, Pro 5V atmega328 should work fine.
As for burning a bootloader, it should be straightforward using a SPI-arduino type bootloader example sketch. Beware however, if you have an older miniwireless, you need to guard against SPI contention during bootload, as it is a shared bus. The older miniwireless does not have a chipselect pullup on the SPI memory or SPI radio, so it is important to give these two GPIO's at least a weak pullup so there is no SPI contention during bootloading. Let us know which bootloader you are using. We need to update our default bootloader, but would like to hear suggestions from our customers as to the preferred choice. I think Papa has some decent traction going on with wireless bootloading, and it might be good to target this bootloader---especially if it can be supported by some default Arduino IDE board selection. If not, then I suppose it's still okay with clear instruction for customers. Thanks for your forum participation.

No worries, I also replied there as well.
I have not heard back from you, but go ahead and send us back the D6/DIO type for free replacements.

Actually, it's just a typical Arduino compatible, so it should behave the same in this regard as other ATmega328-based units.
Were you able to find resolution? If so, please post a response so others may benefit.

Hi CascoLogix,

You are always welcome to return the D6 type for free replacements. Our normal -CW units don't have the radio GPIO connected to D6.
On the page anarduino.com/miniwireless there are links for all the miniwireless types which can be ordered, along with some various documentations.
Let me know if I can be of further assistance.

All orders--whether initiated through our website or from eBay, feature an automated email response with tracking information.
If for any reason you don't receive this automated email within 1-business day of purchase, please let us know immediately at sales@anarduino.com, and we will gladly follow-up.

Cheers,
-Rick

Greetings,

Our email is: sales@anarduino.com

We are the largest US distributor for HopeRF products, we stock them by the thousands, and ship globally.
Components can be purchased from our website, or from our eBay store.

We have our own manufacturing and warehousing in Dallas TX, and our shop is equipped with two robotic pick-n-place machines, and three reflow ovens.
We are also planning to add a third pick-n-place machine Q3 of this year.

Let us know how we may be of service to you.

Best Regards,
-Rick

Here is the schematic for the MiniWireless-CW
MiniWireless CW

Please NOTE, there is also a version of the CW that was created for several customers needing the DIO2 usage of the radio, so we connected this to process gpio D6.

Which type of the MiniWireless ?

Here's a link for the RFM22 that you might find useful:
https://gobotronics.wordpress.com/2010/10/12/rfm22-programming-tutorial-part-2/

It also includes a few different calculators--based on the RFM22 chip revision.

Hi Dan,

Thanks for your excellent contribution here.

We are working with the factory now on producing a custom LoRa with this in mind.
For narrow bandwidth and high spreading factor, it is important to consider crystal tolerance, and in particular a TCXO type crystal would be a useful enhancement.

We have recently received a few crystal samples from the factory, modified a couple radios, and we are also looking into alternative crystals as well.

If you are interested in exploring this further Dan, please send me a private message, and we can arrange getting you a few modified LoRa radios with this in mind.
All I ask in return, is that you report your findings and test results here for the benefit of others who also need to maximize long range usage.

If all goes well, we should have a separate part number for offering the special high-range LoRa radios.
We're focused right now on the RF95/96. but the sample principle could also be applied on the 92/98.

Thanks for your inquiry.

The 73P is far too large to fit on the mini, and there are pinout and charge reservoir considerations, however, send me private message on this, and I'm happy to help you further.

Cheers...

Greetings,

The SPI bus is shared between the Memory and the RFM22 radio.
It is important that the chip select on the Memory is NOT enabled simultaneously with the radio. I believe this is most likely the issue you are seeing.

The chip select on the Memory is the MCU gpio D5 (common between all the MiniWireless). Please make sure D5 is de-asserted while performing radio operations.
You can explicitly set this to a logic HIGH, or by configuring the internal pullup---such that, the memory won't interfere with radio operations.

Let me know if you have any further questions, and although we are quite busy, we are willing to help.

Greetings,

It sounds to me like you have received a special version of the miniwireless which is geared for use with DIO2 connected to D6.
As for schematic, it is the same--except for connection of the radio DIO2 to MCU GPIO D2. Obviously there could be potential issue on D6, depending on your configuration and usage.

We had several customers requiring quantities of this version, and so we had built up 2000 units.
Not sure how you managed to get this one over the normal -CW, as we don't offer DIO2 version--except by request.

We are happy to replace them for you for free.

Here is the schematic for the MiniWireless-CW
MiniWireless CW

Best Regards,
-Rick

Sounds to me like the offset is within acceptable range. Let us know how your project progresses. Thx.

Hi Yariv,

There is same interest in similar situation using the RFM95W.
Here is the link for it:
http://forum.anarduino.com/posts/list/110.page

HopeRF has agreed to manufacture special transceiver using 2ppm TCXO for the RFM95W, but I will inquire to see if they can do the same for the RFM98W.
We have just received sample crystals and will evaluate and test later this week.

The new transceiver with the TCXO will be available for purchase soon, the cost will be only about $0.20 more than the regular 10ppm XO.
We will be purchasing these in volume and making them available for sale as soon as possible.

Cheers,
-Rick

Hi Ken,

Thanks for your post, there is additional information on this in other post, at:
http://forum.anarduino.com/posts/list/110.page

Hi Ken,

I'm adding follow-up information here for the benefit of other customers.

According to HopeRF Engineering...

When dealing with larger spreading factor and narrow bandwidth, it may require use of a higher precision TCXO crystal.
The current crystal used is a 10ppm, so if the bandwidth is < 125Khz and spreading factor > 11, the offset frequency may not meet the application requirements.
HopeRF is now working on manufacturing a new module, with a TCXO 2ppm crystal, which will remedy this situation.

These will cost only slightly more than the normal 10ppm units (about $0.20), and we will be purchasing in volume and offering for sale as soon as possible.

Best Regards,
Rick

Hi John,

Thanks for your input and for letting customers know of your resolution.
I changed the title from: "Poor RF distance..." to "Question on RF distance...",
reason being, these devices have excellent RF distance, and such a title could mislead customers to think otherwise.

Best Regards,
Rick

Hi Ken,

Curious what library you are using for the LoRa's.
We have used the radiohead library quite successfully in several projects.
Seems to be of solid quality, and there are several working examples.
Here's the link for their LoRa class for the RF95.
http://www.airspayce.com/mikem/arduino/RadioHead/classRH__RF95.html
Here's the header file:
http://www.airspayce.com/mikem/arduino/RadioHead/RH__RF95_8h_source.html

I suggest taking a detailed look into the register settings, rate, bandwidth, spreading factor, etc.
Lots of trade-offs. It seems to me this will hold the key for improvement. It sounds like you're already doing quite a bit of this already.

Another place to look is doing some searches on the Semtech LoRa parts. For example, the RFM95 is based on the Semtech SX1276.
I would bet the documentation for the Semtech might have additional details.

Very curious to find out how things are going, and hopefully you will post more here for the benefit of others.
I've heard rumors of excellent ranges, but what range are you finding? What obstructions to you have?

Hi Ken,

Curious what library you are using for the LoRa's.
We have used the radiohead library quite successfully in several projects.
Seems to be of solid quality, and there are several working examples.
Here's the link for their LoRa class for the RF95.
http://www.airspayce.com/mikem/arduino/RadioHead/classRH__RF95.html
Here's the header file:
http://www.airspayce.com/mikem/arduino/RadioHead/RH__RF95_8h_source.html

I suggest taking a detailed look into the register settings, rate, bandwidth, spreading factor, etc.
Lots of trade-offs. It seems to me this will hold the key for improvement. It sounds like you're already doing quite a bit of this already.

Another place to look is doing some searches on the Semtech LoRa parts. For example, the RFM95 is based on the Semtech SX1276.
I would bet the documentation for the Semtech might have additional details.

Very curious to find out how things are going, and hopefully you will post more here for the benefit of others.
I've heard rumors of excellent ranges, but what range are you finding? What obstructions to you have?