The board specs say its power consumption is 19 mA.
It's probably more than that with extra sensors.
Right now I only have an MPU9250 and 4 photocells connected to it.
Data transfer is great and works when both of them are connected to PC.
I realized later that the Nano board requires 7-12V input.
However, I've tried both 6V (720 mA) and 12V (250 mA) solar panels in nice summer daylight and I couldn't get the transmitter to send data properly.
All my values were coming in at 0 on the receiver side.
Any thoughts what could be wrong? The boards lights light up and it appears powered on but no data transfer occurs.
Hi,
If you just have the PV panels connected and no battery storage as your supply, the PV panels will not be able to supply the current peaks when the NRF units TX.
Do you have 10uF capacitors across the NRF supply pins?
Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
@jremington thanks for this.
I recall looking at it previously.
I am so super tempted to use a supercapacitor.
I want to bypass trying to get additional components.
I'm curious as to how long it will hold out in hot weather especially with the electrolytic fluid,etc....
Surely these solar panels can't be that bad.
I can't seem to find anything on these modules regarding peak currents.
A 12V, 250 mA solar panel should easily be able to provide 50 mA on a sunny day.
The max. current consumption of the nrfmodule is listed as 12 mA.
I don't know how much the nano is consuming.
I really wish these guys made a 3.3v version where they combine a Pro Mini with the Nrf module.
It makes the voltage input lower too but that's more of a native voltage regulator design issue.
I did a little experimentation.
I have surge protector outlets with USB ports in the home.
I was able to get successful data from 2 meters away when I plugged it in via the USB port.
Then I plugged it in my bedroom and tried transferring data from the other bedroom (approx. 10 meters away and 4 sets of wall in the way and I got nothing.
Then I tried the same thing about 15 meters away downstairs and I got nothing.
This leads me to believe I need to find some way to increase the range without getting another module with the extended antenna. Although my final application will be outdoors and the the two modules will be near each other.
Here is the github link that the vendor has. It has code and schematics.
I ended up using the code in the link in the first post since it allowed me to transfer float values too.
@TomGeorge the github link will have latest schematics.
I added pictures of them below.
I'm no expert at reading schematics but I think they used 10 nF and 1 nF capacitors instead of 10 uF like you mentioned.
knightridar:
The max. current consumption of the nrfmodule is listed as 12 mA.
I think that is the data for the nRF24 chip. Experience suggests that the typical nRF24 module used with an Arduino needs a great deal more. For example I have working nRF24s powered from the 3.3v pin on a genuine Mega which won't work from the 3.3v pin of a Mega clone.
For a test try powering the nRF24 from a pair of AA alkaline cells (3v) and see if that makes a difference. Be sure to connect the battery GND to the Arduino GND.
Thanks. I tried out something similar to this.
I actually plugged them into 5V/2.4A (it can go up to that) outlets in surge protectors I have around the home.
There is definitely a range when there are walls in the way. I can transmit data successfully 2 meters away line of sight. Receiver was plugged into laptop. Transmitter was plugged into surge protector USB outlet.
When I did it from one room to the other no success (~8 meters and 4 walls in between).
I got a little success but the sun was setting. I had the laptop in room next to backyard. I powered the transmitter with the 12V/250 mA solar panel as the sun was setting and it transmitted a few values. That line of sight distance was about 3~4 meters.
Hi,
You are thinking of the PVs as basic batteries that provide a constant voltage, they aren't.
PVs are a current supplying device and have no storage.
How about you post a circuit diagram of how you have it connected.
Can you post a picture of your project please.
knightridar:
There is definitely a range when there are walls in the way. I can transmit data successfully 2 meters away line of sight. Receiver was plugged into laptop. Transmitter was plugged into surge protector USB outlet.
You should get a much greater line-of-sight range. I have had a pair of low power nRF24s (with PCB antenna) working at 110m range.
When I did it from one room to the other no success (~8 meters and 4 walls in between).
2.4GHz wireless is not good at penetrating obstacles. If you need to do so then the lower frequency HC12 modules would be a better choice.
But get a decent line-of-sight range with the nRF24s and then try them through the walls before deciding they are not suitable.
And get the whole thing working reliably with conventional power before trying it with solar power.
The intended application is for outdoor use.
So things will definitely be line of sight.
I'm just trying things out with transmitter outdoors and receiver indoors due to this hot weather here.
Let's see today what happens with the hot weather and when I use the devices in line of sight range.
I think it will work.
You are thinking of the PVs as basic batteries that provide a constant voltage, they aren't.
PVs are a current supplying device and have no storage.
I agree they don't provide a constant voltage.
I'm using a step down voltage regulator when I was using the 3.3V Pro Mini
but for now due to the combo board below being a Nano (Vin ~7-12V) combined with an Nrf24L01, I'm using the voltage regulator of the Arduino for inputting power from solar panel. I like jremington's link about using the super capacitor, but they too have a life/cost + wondering how long the electrolytic fluid will last in hot weather.
How about you post a circuit diagram of how you have it connected.
Can you post a picture of your project please.
Even using a regulator of any sort between the PV and load will not provide any reasonable regulated output.
I can't seem to find anything on these modules regarding peak currents.
There is no peak current value because a PV is not a storage device.
The PV supplies ALL the energy it can convert to the load, there is nothing in reserve.
The wattage rating of the PV is a laboratory condition measured value, you will rarely attain that amount of energy output.
Take a look at this solar powered remote sensor project, which uses a supercap to store power for night time operation.
Okay.
I think I will go with this option.
I made a spreadsheet of the calculations that Nick Gammon has.
I have some questions regarding the diodes and specs of why he chose what he did.
I will start a separate thread since it seems to be a separate topic on its own.
The module is working I just have to provide it with a 7-12V panel vs. the 6V I used but it still works if the panel was large enough. For example, none of my smaller 5.5V and lower voltage panels provided enough power.
I can say that I can transmit data safely outdoors 5-6 meters and then start to lose range.
If it's indoors with obstructions it is even worse.
