We used example code to study the range of two heltec esp32 lora. I am surprised that the maximum range is 300m
Did you refer to this document?
I was able to get about 30km from a ridge line down into the local city using two of Heltec’s WiFi LoRa 32 boards. I think I was running with the default 14 dBm power setting, but I did invest in a pair of decent antenna for the US 915 mhz band to match the boards. I suspect the antenna is probably the most important thing you can do, plus checking on line-of-sight from transmitter to receiver. It doesn’t have to be completely clear, but you’re sure not going to drive a signal though a mountain range or steel reinforced building.
Thanks Sbmiller. What was the Tx power of the antenna. Did it require external power source to achieve such range.
Did you hit an extra 0 after the 3?
BTW. Which antenna did you use?
It was more accurately 28.25 km (17.5 miles) measured from a transmitter set on the ground on a trail at about 800 m altitude (2600 ft) sending 48 byte packets every few minutes without CRC or FEC to an open location at 61 m (200 feet) altitude. I received 90% of the packets clean for an hour period from several sites at that distance. That was the longest distance I tested because it’s about twice what I think I need. This is all in Orange County, California using the Santa Ana mountains and the city of Anaheim. Since that test I have been running continuous equipment checks across a 1.5 km span in the same area with nearly 100% reception. The location is mostly just a convenience and I will be shifting soon to a 20 km test using CubeCell boards.
The antennas were purchased on eBay and claim 5dBi, but I don’t have the equipment to really characterize them right. They are the best of maybe 10 different kinds I’ve got laying around, but unfortunately both of them are deployed at the moment and difficult to go look at. The vendor was “rfbat” who also uses “Shenzhen Superbat Electronics” as either a source or the company name. These seem pretty well made and are simple rubberized posts with a movable SMA connector. I will probably try to order more, but since the range and LoRa technology looks solid I’m more focused now on getting consistent low power timing out of the CubeCell boards.
Thanks for your detail response. Can you please upload some picture of your antennas?
We spent a long time to adjust the impedance matching of the RF circuit as perfect as possible, but to be honest, we are not satisfied with the currently adapted antennas, We have the relevant equipment to debug and test the antennas, but obviously we do not have the conditions to produce the antenna. So we are looking for a series of antenna solutions, that will make our LoRa series more prefect.