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Aug 13, 2019, 12:07 AM
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Thread OP
Hi, good job !

The idea of not using the nirq line was to have as few wires and components as possible, remember that the ULRS Mini design was created when Hobbyking stopped producing the OrangeRX for a few month and nobody was sure if they would come back some day.

So I made a design that anyone could run even on a prototype board, as you can see the wires between arduino mini and RFM are four consecutive pins to be sure everyone will get it right. I didn't expect many users around the world to create many different PCBs as we have seen, so that was a good surprise.

Of course to make it run without interrupt pin supposes to make some kind of polling to know when the packets are received or sent, which is a completely different logic from the 1.06. This logic allows to know not only when a packet is received, but also when we are receiving a packet.
That's why ULRS 2.X can show the RSSI while receiving a packet, as well as RSSI when not receiving a packet ("background noise") for every channel, to visualize the signal to noise ratio.

About the GPIO lines be careful, they are always required, have a look at the RFM23BP schematic here : http://www.itluxembourg.lu/site/2-5w-narpat-mod/ and you'll see that they pilot a RF switch that connects either the TX pin or the RX pin to the antenna. Not connecting them, or crossing them will likely damage the RFM.
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Aug 13, 2019, 10:22 AM
Registered User
Thank you. I think I know what I was doing wrong when trying to get it to work without the nIRQ line.
I'll try again. You are awesome! really.
Aug 13, 2019, 05:04 PM
Registered User
Thread OP
Thanks and good luck
Aug 16, 2019, 12:37 AM
FPV Melbourne
yak-54's Avatar
Quote:
Originally Posted by Rusty105
RasPi are nice, but don't have any way, in stock form , to perform a safe shutdown. If you just kill power to the Pi, you run the risk of corrupting the file system on the MicroSD card. And that could be bad......
I have found that only happens if you use crap cheap SD cards with good one I could not get it to fail power off before it finish loading And back on 10 times in a row
Aug 16, 2019, 03:46 AM
Registered User
Quote:
Originally Posted by yak-54
I have found that only happens if you use crap cheap SD cards with good one I could not get it to fail power off before it finish loading And back on 10 times in a row
I noticed the same.
Aug 16, 2019, 03:56 AM
Registered User
Thread OP
No problem so far with sd card, and it wouldn't be an issue to add a "clean shutdown" either as a hardware button or as an icon on the touchscreen.
Aug 16, 2019, 04:05 PM
Registered User
Hey Flip Flap, got it to work without the nIRQ line. Works great, identical to when using the interrupt. Once I stopped trying to poll the interrupt status register and polled the EzMAC status register instead it all came together. It's been a fun learning exercise. Thanks for making it possible. If you ever plan on going to Texas let me know, want to buy you a beer or two.
Aug 17, 2019, 03:47 AM
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Thread OP
Excellent, yes the ezmac register is very useful for this. Thanks for the beers !
Aug 28, 2019, 07:54 PM
Registered User

New mini


Flip Flap, I am working on a new mini and was wondering what was the reason for going from the 3.3K resistors to
the 1K resistors?
Aug 28, 2019, 09:55 PM
Registered User
Thread OP
This is to reduce the risk of interference on the pins. For example if touching the pins, or RF interferences with the pins.
Sep 02, 2019, 04:47 PM
Registered User

New Mini


So I just sent off for a first run of the ULRS mini called the Firefly.
It uses SMD but is very simple and doesnt have many components to solder.
It has 30.5mm square mounting holes. Picture and schematic below.
Wish me luck, this is my first try at this.
Last edited by bjam03; Sep 06, 2019 at 05:27 PM. Reason: Update schematic
Sep 03, 2019, 12:07 PM
Registered User
Thread OP
Hi William,

That's small ! Keep up good work, and I'd recommend to keep a 6 pins serial so that the FTDI can be plugged in directly. The 5th pin that you marked as GND on the schematic is actually the CTS on the FTDI adapter, and not the GND. (have a look here : http://www.itluxembourg.lu/site/the-ftdi-adapter/ )
Sep 03, 2019, 12:51 PM
Registered User
Quote:
Originally Posted by bjam03
So I just sent off for a first run of the ULRS mini called the Firefly.
It uses SMD but is very simple and doesnt have many components to solder.
It has 30.5mm square mounting holes. Picture and schematic below.
Wish me luck, this is my first try at this.
Congratulations, this is the first mini with mounting holes.
Will be compatible with the mounting of several flight controllers and video transmitters.
Very good, thanks for your effort and good luck!
Sep 03, 2019, 02:15 PM
Registered User
Thanks Flip Flap, I'll make the change. For now I'll just connect the CTS pin and the ground pin on the FTDI adapter together.
This board should run both firmware 2.0 and the slightly modified 1.06 firmware. I kept the NIRQ line because with version 1.06 on the transmit side the code works better with it, havent worked out the timing to perfection yet. :-) On the receive side the NIRQ line is not needed at all. and of course with version 2.0 it is not needed on either side.

I have used some of the gisley code to inject MAVLINK packets via the I2C bus (v1.06) and got
it working well I think, havent actually flown it yet thouogh. I'll update as I make progress.
Sep 03, 2019, 02:19 PM
Registered User
Thanks Helixerox!


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