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Post by treadd on Nov 15, 2016 19:35:01 GMT
Hello, Let me first start by saying I have a fully functional v2.4 Gateway and one multi-sensor RFM69 (433MHz) node running with MQTT and Openhab. This setup is using the 3.3v/5v selectable voltage BUONO boards for the gateway and node as suggested in the original Uber Home Automation Instructables. The problem I'm having is trying to use a 5V Uno clone using the CH340G chipset. The issue is not the common one of drivers/visibility to the OS/IDE, but being able to run the RFM69 node sketch. I can successfully upload and run the Blink sketch on these Uno clones without issue. I have a project shield with an RFM69 and two bi directional level shifters to take care of the voltage and hookups to the RFM. I know the shield/level shifters/RFM is hooked up correctly as I can place this shield on a BUONO (set to 5v) and it instantly starts feeding messages to the MQTT server. However, when I upload the RFM node sketch and place the shield with RFM on the Uno Clone, I get a steady power light, and nothing else. TX/RX lights do not flicker, and no MQTT messages. EDIT- I have a few of these clones, and have tried on two with the same result. Did I gamble on super cheap boards and not realize some inherent incompatibility? Thanks! -treadd
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Post by papa on Nov 16, 2016 0:29:17 GMT
treadd, sorry you are having a problem. I wonder if your RFM radio is not getting enough current on the clone with the CH340G chipset. Look at this data sheet that compares a Buono with a regular Uno See how the Buono at 5v supplies a lot of current (2A), more than a regular Uno (500mA). It would make sense that the Buono at 5v would have enough current to run the level shifters & RFM69 radio. At the end of this, it says "The GPIOs provide 40mA with the exception of the ground and VIN pins which provides 200mA, according to the datasheet." My quick search did not find that data sheet, but if this refers to the same clone & is true, your clone has much less current than the Buono's 2A at 5 volts. I imagine the level shifters also consume some power. Your clone's current supply reduced by the level shifters may mean the RFM69 radio does not have enough current to work with. Anyway, that's my thought. Someone like computourist could give a better read on power requirements.
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Post by treadd on Nov 16, 2016 2:33:55 GMT
Hi papa, First thank you so much for taking a look at this. It seems I have a lot more to learn about the various differences between not only all the Arduino boards, but how all the clones differ as well. I will report back if I can find the cause, starting with your suggestion regarding possible power issues. It would be cool to get these cheap boards to work, although we could have a long discussion about time spent troubleshooting vs the few dollars saved per board. Thanks again! -treadd
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Post by treadd on Nov 16, 2016 3:12:18 GMT
Ok so here is a quick update, and a question that I'm not even sure I'm even 10% qualified to ask.
First, I need to mention that the BUONOs that are the gateway and node that are working, are set to 3.3v via the onboard switch. According to the BUONO datasheet, current is 300ma @ 3.3V. The voltage regulator on the clone Uno is an AMS117-5.0, which according to it's datasheet can supply 1A.
Of course this is a huge assumption, as I have zero idea what lies between the voltage regulator and an I/O pin or VCC pin that could change those 'raw' component specs.
So here is my ultra noob question- I have a few MCP1825S (5V+ IN to 3.3V OUT, 500mah) voltage regulators. could I try to run a separate line from a 5V power supply to the MCP1825S, and hook the RFM 3.3V supply pin to the 3.3V OUT on the MCP1825S?
While this sounds horribly cobbled together, there is part of me that wants to figure this out and come up with a solution, even though I've gone far past any kind of savings (time or money) to make it a reasonable solution. Of course anyone could jump in and say 'this is not worth the effort' and I will drop it like a hot potato. (And just buy a few more BUONOs) My inexperience is keeping me from knowing at what point it's just not worth pursuing.
Thanks!
-treadd
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Post by papa on Nov 16, 2016 19:31:15 GMT
Again, treadd, I'd feel better if computourist weighed in on this power needs / supply stuff because he knows it better.
That said, I'll make a stab at answering ...
You say/ask, "I have a few MCP1825S (5V+ IN to 3.3V OUT, 500mah) voltage regulators. could I try to run a separate line from a 5V power supply to the MCP1825S, and hook the RFM 3.3V supply pin to the 3.3V OUT on the MCP1825S?"
I believe this could work to supply power to the RFM69. I believe to be done correctly (on the principle of "shared" or "common" gnds), connect MCP1825S Gnd to RFM69 GND AND to Arduino GND. Connect MCP1825S 3.3v output to ONLY RFM69 vcc.
I'd think you'd want to try the above (extra power supply) once to see if your problem truly is the clone's lack of current to power the RFM69. If adding the extra power supply works, you'll have to judge whether this solution meets your needs.
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Post by treadd on Nov 17, 2016 0:10:24 GMT
Hi papa,
Thanks again for your advice. I will try powering the RFM from the MCP and report back!
-treadd
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Post by computourist on Nov 17, 2016 12:46:28 GMT
Hi papa, treadd, Interesting problem you have.. On the original Arduino 2009 board the 3.3 Volt supply was provided by the FTDI usb->serial chip. Since the board you use replaces the FTDI chip with the CH340 the 3.3 Volt has to come from another source, because the CH340 lacks such a source. The RFM module needs 130 mA when transmitting. I think it is best to derive the 3.3 Volts power supply from the 5.0 Volt supply using a separate voltage regulator, as you suggest. That's what I always do and I have not had any power supply issues with this setup. Rgds, Computourist
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Post by papa on Nov 17, 2016 21:53:59 GMT
Thanks, computourist. As I said, it's good to have your expertise on matters like this.
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Post by treadd on Nov 18, 2016 6:22:52 GMT
Thank you both for the help on this! I have not had a chance to try this out yet, but plan on it in the next day or two.
-treadd
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Post by treadd on Nov 18, 2016 20:06:20 GMT
So it didn't work. Sometime later on I may swing back to mess with this again, but for now I'm throwing in the towel. I ended up not using the MCP regulators, but another power breakout board I had that was 3.3V/5V selectable voltage @ 700mah with a 9V battery. The 3.3V out was connected to the VCC and ground of the RFM69, and the rest of the Uno clone being powered off of USB. Still same behavior. Also I completely forgot to mention that once the node sketch is uploaded to the clone board, I get no output at all on the serial monitor. I tried switch the baud rate around, and debug is uncommented, but same results. (I read something about the CH340 cboards not being able to be connected to USB and do serial output) I'm sure there is an answer, and a very much appreciate everyone's time looking at this. If anyone wants to keep trying with me, I will give anything a shot, but at this point am going to order a few more BUONOs for use with Openhab and keep some forward momentum on this project. Thanks again for the help! -treadd
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Post by papa on Nov 18, 2016 21:26:20 GMT
Thanks for letting us know your latest results, treadd. Sorry they were not better.
Probably just as well that you move on from the CH340 boards. With what you were having to do like level shifters, extra power supplies, etc, it seemed to be getting ungainly.
Best wishes & much success when you get the opportunity to continue building nodes. & remember to be patient with the project & yourself.
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