I am making a low power repeater using a 3.3v arduino and E32-900T20D module.
All I want repeater to do is receive any sent message, then resend it. I will have this device with bigger antenna mounted on roof for maximum line of sight.
What is best setting for this use case? Fixed or transparent?
I don’t quite understand the high and low address bits… do they need to be set when using transparent?
Thanks! The libraries provided have been very helpful for interfacing these modules. I am successfully able to send and receive messages between pi pico with micropython module and ATMEGA328P with arduino library.
you must create a repeater specified for your kind of network.
If you create a transparent transmission network, you must use a transparent transmission and set the devices on the same ADDH ADDL and CHAN, but every time you repeat a message also, the sender receives It.
For the fixed transmission you must create/manage a protocol or similar.
For example, you want to repeat a message that all devices must read: you must send the message to the repeater, and the repeater sends a broadcast message.
If you want to send a message to a specified device, you must send the message to the repeater (or broadcast), and the repeater reads some information inside and sends a specified message.
There isn’t a specified solution.
For example, E22 has the repeater function, but It’s quite complex; here is a schema.
I’d also like to ask you if you have some problems with the interoperation of MicroPyton and Arduino env because @Woto opened a topic on this forum with some encoding communication problem that I can’t replicate, can you give some advise to he please.
My idea was the sender sends the message, if the repeater receives it, the repeater wakes up the radio module and arduino, reads the message, then it resends it.
The sender waits for 5 seconds after sending, and if it receives the same message back, it uses that as a confirmation that the message was received by repeater, if it doesn’t receive it back, option to resend.
I will look into fixed mode with addressing, could be cool if multiple devices can use repeater to direct messages to devices with seperate channels or addresses, and have confirmation end node received message.
I have had some issues getting arduino to talk to pico, with some “unicode” errors and such… but I think I have narrowed it down to timing issues. My case is different than linked thread as my repeater microcontroller and e32 module are both sleeping, so I had to add calculated delays to sender and repeater to make sure there were no conflicts…
I will be playing around with settings more, as well as take a more in depth look at code from linked thread to see if I can figure out whats going on…
In linked thread, code is trying to send messages very frequently. To me this is not food practice for lora devices. And in some countries there are limits to the amount of data sent in a certain time period. In my opinion 1 message per 30 seconds sent from each device should be max. This also allows devices to time each other better and spend more time listening.
I have been using Pi Pico and Micropython for several years, but completely new to arduino and Arduino IDE. So learning as I go…
Attatched are photos of schematic and 3d view of PCB I am designing for low power Arduino repeater. I have tested this setup on breadboard and it works fine. The 3.3v LDO I am using can supply up to 250mA, and I have not had any issues with power using this LDO. I have put place for 100uF capacitor on PCB incase it’s needed.
On breadboard I am not using pullup resistor on TXD and RXD and it works fine. I did need to use pullup on AUX.
On Pi Pico, I needed pullups on TXD, RXD, and AUX. I believe Pico’s internal pullup is much higher value than ATMEGA328p… Unsure though.
I put optional pullup resistor spaces for all pins of E32, as well as I2C header for BME280 sensor (in case a different I2C sensor installed without pullup already.)
M0, and M1 do not need pullup correct? I am not using pullup on breadboard setup, but decided to put space for them on PCB in any case it’s ever needed.
PCB size was designed for this box: 115 x 90 x 55 mm I did not put any mounting screw holes, as the space inside the box is perfect fit. SMA connector will protrude into hole drilled in box, with o-ring and washer.
5v solar cell will be sealed to lid of box, and charge battery when sunny. a 200mA solar panel should keep LiPo charged as this device only uses <1mA when sleeping…
Here is a 3d view and schematic of the Arduino repeater I am making. I appreciate any ideas. I was designing this to specifically fit inside this box: https://www.amazon.com/dp/B092HS9CMR?th=1
Solar panel will be sealed to outside of box, and SMA connector will protrude through box, sealed with an o-ring.
Code can be modified to use as a TEMP/PRESSURE/HUMIDITY sensor node, or connect any I2C or SPI sensor.
The PCB is exactly as I have it setup on breadboard. I put option for pullups on all lines to E32 module… I don’t think M0, and M1 need them, but there is a space there incase it ever did.
This device is ATMEGA328p running at 8mhz on internal oscillator, 3.3v. The HT7333 LDO seems to have no trouble at all powering LORA module and arduino IC. It can supply up to 250mA. On breadboard I have used it without the 100uf capacitor shown in schematic. I added that to be optionally put in if needed.
What is interesting… on arduino setup I have, 3.3v, pi pico setup, also all 3.3v. Pi pico needs pullups on TXD, RXD, and AUX. Or it will not work.
Arduino setup, only pullup on AUX works, TXD, and RXD not needed. Any reason why? Does arduino chip have lower value internal pullup resistor than pico? I think pico internal pullup is 70k…
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