Hi Floyd.
5m deviation, I wouldn’t expect better than that.
I use the Esp32 C3 mini module with the gps module.
I have added a button.
every time the button changes position
a log point is saved in a file in the LittleFs file system.
I also added wifi,
so it is possible to download the log file.
You can see an image and code in the link below
if you should be interested.
drive.google.com/drive/folders/1yZrISHWsS-RxwEnvy-fmbnBvmO1kIYpH?usp=sharing

Agreed.
Even though the M8N is capable of reception from the Russian and Chinese satellites it seems to rely primarily on the GPS system. Since I posted earlier I have improved my setup by moving the antenna out and away from the house so there is a fairly clear and unobstructed view of the East, 0-180 degrees. Signal strength increased almost twofold with a corresponding improvement in the C/NO. The house still obstructs the view to the West but just this one improvement seems to have cut the deviation to half or better. It will need to run for several more hours to get a better comparison to last night’s run but so far it’s holding to within 5m.
It all comes down to quality of reception.

Hi Floyd.
Thanks info.
the advantage of the M8 is that it should be able to see more than US satellites, I think.
Although the Neo-6M is a rather old module, I think it works quite well.
Maybe it’s consuming too much power.

Hi JB,
Yesterday I decided to run my own evaluation to see how it stacked up against Andreas Spiess’s work. I put U-Center to work and ran the deviation map for a 12 hour period overnight. My M8N is connected using a DSD Tech SH-U06B USB to TTL Serial Adapter and a Bingfu antenna affixed to the inside of a window in my house which faces E/NE (not ideal but adequate for this initial experiment). While the receiver was seeing multiple satellites, those with the strongest and best C/NO signals were located in the East-North quadrant. No surprise there. I was seeing an average of 18 satellites at any given time with an almost even mix of GPS and GLONASS. There were no BeiDou but I think that is an option I can enable in the M8. I will have to look into that further. With U-Center it is easier to see and begin to understand why the excursions in readings take place. Back to the results though…
This morning I was pleasantly surprised to see my 12 hour evaluation using my less than ideal setup showed average position was within 10m radius (99%) and the remaining were within 15m.
I will try to get my antenna set up in a better location and run this test again at some later date.

Hi Floyd.
I thank you for your reply.

Here is a link to Andreas Spiess’s YouTube channel.
Comparison of precision between Neo-M8N and Neo-6M Modules.
youtube.com/watch?v=FmdG66kTfsI

void loop() {
// This sketch displays information every time a new sentence is correctly encoded.
unsigned long start = millis();

while (millis() – start < 1000) {
while (gpsSerial.available() > 0) {
gps.encode(gpsSerial.read());
}
if (gps.location.isUpdated()) {

and then use the if else statement.
if (millis() – start < 200) {

}
else{
while (gpsSerial.available() > 0) {

and then
start = millis();
after the last serial.println