Hey there,
I’m a student in Germany and new to ardupilot, and I am currently planning a new project for my lawnmover. i have some ideas on how to controll the mover, but i think normal gps is too inexpensive. So I started looking into rtk gps systems. I’m a student, so I’m on a budget and i am trying to stay under 100€. I stumbled up on the lc29h from a blogpost.
But nobody seems to use this for their projects. Is can i use this or is there a better alternative i did not find in the 70-100 price range.
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I have never seen them before, but they are really cheap. It looks like they should work but you will have to work out the details.
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They output NMEA, so in theory they should be supported. Maybe I’ll order one too, nice find!
Since you mentioned RTK, only the LC29HBA (with IMU), LC29HDA (1Hz update rate) and LC29HEA (10Hz update rate) support RTK.
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I was just looking at that. The Aliexpress link shows a LC29HEA for $46 so I suppose it should work. $58 w/ antenna, pretty cheap.
Their User Forum has some posts about these. If it doesn’t work contact them for the latest firmware as that seems to have been a problem in March of this year. Who knows what you will get from Aliexpress. They also say fixed at 10Hz. That might be a problem if true.
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Looks like they are fixed at either 1Hz or 10Hz, depending on the model. Hm.
Worth a post to their forum asking for firmware for 5Hz!
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Let’s see 
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Are you a high school student or a college student?There is a sponsorship program here to sponsor GPS
Update: They already implemented selectable update rate (1Hz/2Hz/5Hz/10Hz) in a firmware update for the LC29HEA. Currently trying to get my hands on it and the permission to redistribute.
I think I’ll go ahead and order one of them.
@Tobik Sorry for kinda-hijacking your thread, but it’s kinda-related 
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This would be the cheapest entry point for RTK. Free Ntrip here.
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Thanks for all the replies. I think I’m also going to buy one Lc29hea and try to get it working. Maybe if one of you managed to set this up you can provide some information about the setup.
It’s L1 and L5 I think L1 and L2 is more popular. Could this be an issue when I try to use free ntrip data like rtk2go.
I only found the LC29HEAhttps://a.aliexpress.com/_Eun6NCT
And found the LC29HDA https://a.aliexpress.com/_EGeLHsx
But the 1Hz refresh rate is to low for it to be moving.
What GPS do you guys plan on getting
@Oli1 no problem it’s interesting to follow you thoughts. And thanks for asking for the firmware in the other forum. What did you buy?
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L1/L5 should be fine. L5 might be a bit less precise but it has better obstacle penetration and higher transmission power in general.
I went with the dual LC29HEA module (your first link) since I’m mostly interested in onboard RTK for yaw. LC29HEA is the only module that really makes sense for our applications, the others either have only 1Hz update rate as you noted, or include an IMU which adds costs but most people won’t require.
Note: 10Hz update rate is considered too high for Ardupilot, but newer firmwares for LC29HEA allow switching between 1/2/5/10Hz, with 5Hz being what we want.
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Thanks for your reply. I think I’m going with the single module. I’m planing to attach it to a lawnmower. Is a magnetometer good enough or do you recommend in general rtk for yaw.
Now that I got the module I’m searching for an antenna. What antennas are you using or do you have a goo to antenna you could recommend?
Mag should be fine. I don’t have much Rover experience, but moving baseline RTK (i.e. yaw) is a rather recent addition, and I’m pretty sure we had decent navigation before that. LIS3MDL is a low (but not ultra low like the Honeywell clones) cost mag that I’ve had good experiences with.
Re:antenna, I’m going to go with these, so it’s a consistent low-cost package. Same caveat applies like with the GPS module: Can’t guarantee for anything, looks like nobody here has tested them before, so we’ll have to see how it goes
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It seems slightly unclear - is there a model in that line that supports baseline operations?
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it looks like it does
https://www.quectel.com/download/quectel_lc29hea_moving_base_application_note_v1-0
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I’m going to try out my luck with this rtk unit https://a.aliexpress.com/_EQlaf2r
And this antenna https://a.aliexpress.com/_EIvX7U3
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Both look promising, keep us updated.
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