Hello everybody,
I've got an Erisin head unit.
It was delivered with a generic indoor GPS antenna, and I fixed it on the car's wind-shield.
The problem is that whatever the app I use (Google map, Waze, etc...) positioning accuracy is very poor. I tried many other positions for fixing the antenna on the wind-shield, and even outside the car, the problem is identical. So, I tried another indoor antenna, this time a known brand (Tomtom) and the problem is identical.
I measured voltage on the GPS output port, and it's 3.24V (antenna works in 3 to 5V range).
In the mean time, my phone (Blackberry Key 2) positioned on the dashboard, with exactly the same app is very accurate and smooth.
Have you any ideas of other factor that can influence GPS accuracy ?
Thanks a lot in advance.
Pascal
Related
From what I've read android auto head units will use the gps in the car if available and not the one in the phone, this is great because using the one in the phone causes a lot of strain. My car doesn't have a gps antenna in it because it's old, but I could just as easily buy a gps antenna and hook that up to it. My question is does anyone know how to tell if a head unit will use the integrated antenna in a head unit, and if it doesn't have one, if there is a way to add your own gps antenna to the head unit that android auto will use?
Woohoo
Update: I've just found that this head unit https://www.crutchfield.com/p_113DDX9903/Kenwood-Excelon-DDX9903S.html?tp=5684 in the details tab of the page says it has gps for that purpose "GPS Antenna: The Kenwood head unit comes with a GPS antenna to enhance the performance of CarPlay and Android Auto navigation maps."
If you guys have android auto and it's killing your battery, you can also split a cable, bring the data from a cable to android auto and the power to a charger with more capacity like this, https://www.amazon.com/dp/B0047AALS0/_encoding=UTF8?coliid=IWYI0PRVEE5D&colid=35S1KKGXU6BEJ. Note if you just wanna buy that one it apparently pulls a good amount of power this user on redirect reported https://www.reddit.com/r/AndroidAuto/comments/48e65c/way_to_fast_charge_with_android_auto/ Also, if you haven't gotten one yet, if you can afford it opt for one with gps like that kenwood, it won't use the gps in your phone, or at least it shouldn't, and thus it will drain your phone battery heavily less. GPS is why your phone gets so hot and uses so much battery when you're using maps or android auto navigation.
Sorry for the blast of info but I couldn't find any summaries of this anywhere so hopefully people can get this info now.
The Sony has an add on to add GPS, but it is about $300, which is almost the price of the actual head unit. That being said, the Sony pumps out 1.5a, and easily powers up my S8+ while using music and GPS
Does anyone know what type of GPS antenna's these units use?
I have an Xtrons PX5 Oreo head unit, but I'm having difficulty positioning the GPS antenna in a good location, due to lack of space under the dashboard.
I'd like to buy another antenna, to take apart and get rid of the plastic cover, in the hope that it will be a bit smaller and I can squeeze it under the dash
However I'm not sure if all antennas that I can buy are the same.
The socket type on the back of the Xtrons unit appears to be a type called FAKRA, and the antenna that came with the unit has a right angle connector.
I can find loads of similar looking antennas on eBay and AliExpress etc, with FAKRA plugs, but most of them are straight (so I'll need to check if a longer plug would be a problem.)
But apart from that... Does anyone know if there is anything specific I need to look out for when buying another GPS antenna ?
Some antennas say they are "Active" and are powered by between 3 and 5V, but I presume they are all like this ?
Also, I've seen splitter cables, which would suggest that I could install more than one GPS antenna, but I'm not really sure if thats possible either ??
Thanks
RogerClark said:
Does anyone know what type of GPS antenna's these units use?
I have an Xtrons PX5 Oreo head unit, but I'm having difficulty positioning the GPS antenna in a good location, due to lack of space under the dashboard.
I'd like to buy another antenna, to take apart and get rid of the plastic cover, in the hope that it will be a bit smaller and I can squeeze it under the dash
However I'm not sure if all antennas that I can buy are the same.
The socket type on the back of the Xtrons unit appears to be a type called FAKRA, and the antenna that came with the unit has a right angle connector.
I can find loads of similar looking antennas on eBay and AliExpress etc, with FAKRA plugs, but most of them are straight (so I'll need to check if a longer plug would be a problem.)
But apart from that... Does anyone know if there is anything specific I need to look out for when buying another GPS antenna ?
Some antennas say they are "Active" and are powered by between 3 and 5V, but I presume they are all like this ?
Also, I've seen splitter cables, which would suggest that I could install more than one GPS antenna, but I'm not really sure if thats possible either ??
Thanks
Click to expand...
Click to collapse
What for a car do you have? (brand & model)
Xtrons TE706PL. It has a FAKRA connector on the back.
Since I posted, I've ordered a generic GPS antenna from AliExpress which has a FAKRA connector on it, (for less than $10)...
So I'll see if that works.
What I don't know however if these antennas are Passive or Active. I presume they are mostly Active, where between 3 and 5 volts is supplied to the antenna, via the same cable (coax) where the signals are sent into the unit (capacitive coupling)
As GPS signals are at 1500Mhz, the loss on thin coax is extreme, so I'd be surprised if any of these antennas, which come with several metres of coax, are passive.
(But I could be wrong.. In which case I'll probably also try to shorten the coax to just the length I need, as that will also improve GPS reception)
RogerClark said:
What I don't know however if these antennas are Passive or Active. I presume they are mostly Active, where between 3 and 5 volts is supplied to the antenna, via the same cable (coax) where the signals are sent into the unit (capacitive coupling)
Click to expand...
Click to collapse
What was your determination on this. Does the radio use an active antenna or passive?
btw, its an active antenna. I bought a replacement antenna from anywhere they sell active gps antennas.
Hi
I have a Joying UO138P4V 4Gb Rockchip PX5 32Gb Android Oreo 8 inch unit. Loving it. But I hate the GPS showing 6% higher speed at all speeds. My old wince unit GPS used to show accurate speed. I have double checked with other ways and confirmed the issue. It’s same in all navigation programs I tried including iGo, ware and Sygic, and also in speedometer apps, so I know it’s an android system issue. Repositioned GPS antenna to windscreen and now have plenty of satellites but didn’t solve the problem.
Does anyone know if the vehicle speed given by android head unit can be corrected?
Thanks
asujithdr said:
Hi
I have a Joying UO138P4V 4Gb Rockchip PX5 32Gb Android Oreo 8 inch unit. Loving it. But I hate the GPS showing 6% higher speed at all speeds. My old wince unit GPS used to show accurate speed. I have double checked with other ways and confirmed the issue. It’s same in all navigation programs I tried including iGo, ware and Sygic, and also in speedometer apps, so I know it’s an android system issue. Repositioned GPS antenna to windscreen and now have plenty of satellites but didn’t solve the problem.
Does anyone know if the vehicle speed given by android head unit can be corrected?
Thanks
Click to expand...
Click to collapse
Do you have a CAN bus installed? If so, your speed is derived from your car, never from your GPS.
It’s a 2003 Lexus LS430. It has canbus I believe, I haven’t installed any separate module during head unit installation. Just an ISO harness to connect to the vehicle. Philips WINCE unit that was there before used to show accurate speed. And the speed shown in car speedo is different from the current Joying GPS speed.
asujithdr said:
It’s a 2003 Lexus LS430. It has canbus I believe, I haven’t installed any separate module during head unit installation. Just an ISO harness to connect to the vehicle. Philips WINCE unit that was there before used to show accurate speed. And the speed shown in car speedo is different from the current Joying GPS speed.
Click to expand...
Click to collapse
If your car speed is different from your units speed, then the unit is not using the car speed from the CAN bus. If you only have an ISO harness without a can bus "black box", then your unit did not come with a can bus. (note that you might have 5-7 CAN buses in your car, although a 2003 model probably not).
How do you know your WINCE unit was correct and your Joying unit is not? Of course it is the same in multiple apps on the unit: they all use the same source.
Did you compare with your phone or some external GPS device?
If I disconnect my CAN bus, my GPS speed is correct. That doesn't help you of course, but I mention it here to make clear it is not a general problem of these units.
Thanks Surfer63.
The wince unit speed accurately matched my iPhone and iPad gps speedometers and Navi programs, and also onroad speed displays - advisory speed displays and temporary slow down boards with speed display at road works. Compared to that gold standard, my previous Toyota Camry was accurate (the wince unit was previously in my Camry), current car speedo shows 3% extra (so I put cruise at 103 for 100kmph) but joying gps will show 106 kmph, way off. It’s annoying as iGo will beep overspeed warning at all speed cameras.
asujithdr said:
Thanks Surfer63.
The wince unit speed accurately matched my iPhone and iPad gps speedometers and Navi programs, and also onroad speed displays - advisory speed displays and temporary slow down boards with speed display at road works. Compared to that gold standard, my previous Toyota Camry was accurate (the wince unit was previously in my Camry), current car speedo shows 3% extra (so I put cruise at 103 for 100kmph) but joying gps will show 106 kmph, way off. It’s annoying as iGo will beep overspeed warning at all speed cameras.
Click to expand...
Click to collapse
On the Sofias there is an issue with the GPS software. It uses integers instead of floats to calculate the speed in meters per seconds, which resulted in rounded 4 km/hr increasing/decreasing steps.
On the PX5 on the April and June ROM I did not encounter issues, and I have it always on the CAN bus. Only for tests I disconnected the CAN bus.
On which ROM version are you?
This is the device info screen. It’s the stock ROM, unmodified, not rooted.
https://imgur.com/a/q0mjL3v
I have a joying head unit, with the same issue observed. Very annoying! Is there a fix to it?
What is your opinion about using the cheap included GPS antenna (more or less the same one comes with all head units) hidden behind the dash? Is it as good as connecting the head unit to the car's old GPS antenna?
I reused my Toyota factory GPS antenna (by means of a connector adapter available on the Internet) and the satellite reception is perfect.
The factory antenna is generally located in the best car's reception position, often difficult to reach for installing a new GPS antenna.
Yes same here with my Skoda. My aerial is a combined DAB & GPS so no need for a USB DAB connector either and reception for both is perfect
Hi All,
I have just installed a Klyde PX6 unit in my CX5 (with Bose). All is fine except for a GPS issue (built in). The GPS is showing a huge lag in position and speed updates as can be seen in the videos. One video shows same app running on Klyde unit and my mobile.
I need to send commands directly to the MT3337 GPS chip or replace it with a non averaging unit (real time/ live updates). It would be good if I can access the NMEA data stream to confirm it's the GPS chipset/module or the the android service being delayed/not serviced regular enough.
Klyde unfortunately have been a little more than useless with their engineer saying its normal GPS behaviour. Maybe for China but not for the rest of the world. I sold GPS modules for 10 years and never saw this behaviour.
Any clues on how to address this?
You should use the GPS mouse which has been delivered with the unit, instead of using the OEM on the roof.
You would have the same behavior with most OEM installed GPS antennas, independent of the car.
I am using the supplied GPS antenna.. there is no way to interface the tomtom Mazda factory one.
malster181 said:
I am using the supplied GPS antenna.. there is no way to interface the tomtom Mazda factory one.
Click to expand...
Click to collapse
1 minute ago
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#3
I am using the supplied GPS antenna.. there is no way to interface the tomtom Mazda factory one.
This PX6 is using a MT3337 chipset. I'll try interfacing to the NMEA (TX DATA) stream from the MT3337 and see if it is delayed at that point. If so, then it's a config issue in the MT3337. If it's not delayed there, then it's a Klyde issue.
Also discovered the ODB2 Bluetooth interface is not working.
Illumination wasn't working originally, I had to put a 4.7K resistor to ground as it wasn't pulling low enough for it to register lights were off...
Not been a great experience with this Klyde thing. Was looking forward to importing them for resale, but not now if this is the sample unit performance.
malster181 said:
This PX6 is using a MT3337 chipset. I'll try interfacing to the NMEA (TX DATA) stream from the MT3337 and see if it is delayed at that point. If so, then it's a config issue in the MT3337. If it's not delayed there, then it's a Klyde issue.
Also discovered the ODB2 Bluetooth interface is not working.
Illumination wasn't working originally, I had to put a 4.7K resistor to ground as it wasn't pulling low enough for it to register lights were off...
Not been a great experience with this Klyde thing. Was looking forward to importing them for resale, but not now if this is the sample unit performance.
Click to expand...
Click to collapse
tbh... I still have 3 different Klyde units working in car and bench and had some more in the past.
None of your reported issues have ever been observed on any of my units.
OBD2 BT issues are only if you bonded any phone before you added the BT stick. BTW... not all sticks are working. That is a common thing in Chinese radios.
btw... If you have any issues, you just should ask Klyde. They are really responsive, at least if you ask Fany.
Hi Rigatoni,
As I said, I have asked and they are not so helpful. Insisting the GPS functionality is normal. If I drive atv60k/hr and stop, GPS takes up to 15 secs to show a stop or slow down. I have sold GPS in a past life both commercial and military and never seen such a lag before. Even old SiRF and Siny chipsets are so much faster.
Klyde did give the pinout if the GPS module, so I'll start but analysis of the MT3337 data stream. I have a few other GPS modules here I can try pop in it.
Anyone know if there is a config file in Android or the Klyde somewhere that sends the commands to the GPS module to set it up, eg set buad rate, sample rate etc? Or is the MT3337 just running default settings?
As for the ODB2 I wasn't aware of that issue, and again Klyde hadn't advised of it. The ELM unit was also supplied by Klyde. So how do I undo the hijacking of the serial port by a phone and release it for ODB2…? Factory reset?
malster181 said:
Hi Rigatoni,
As I said, I have asked and they are not so helpful. Insisting the GPS functionality is normal. If I drive atv60k/hr and stop, GPS takes up to 15 secs to show a stop or slow down. I have sold GPS in a past life both commercial and military and never seen such a lag before. Even old SiRF and Siny chipsets are so much faster.
Klyde did give the pinout if the GPS module, so I'll start but analysis of the MT3337 data stream. I have a few other GPS modules here I can try pop in it.
Anyone know if there is a config file in Android or the Klyde somewhere that sends the commands to the GPS module to set it up, eg set buad rate, sample rate etc? Or is the MT3337 just running default settings?
As for the ODB2 I wasn't aware of that issue, and again Klyde hadn't advised of it. The ELM unit was also supplied by Klyde. So how do I undo the hijacking of the serial port by a phone and release it for ODB2…? Factory reset?
Click to expand...
Click to collapse
Strange with your GPS... never seen that. I use TomTom in my units and it doesn´t lag more than 1 second in bad cases.
To change the GPS module you need to get into the rooted system. Out of memory I don´t know the exact path. I also have only a PX6 on hand, but this has a complete different MCU and I don´t know if this is the same. Will have a look tomorrow after the files for it to change.
To get the phone off of the unit, you need to first of all close BT connection on your phone.
Then remove start the radio and remove the connection from the radio... completely.
Shut down the radio
Turn BT on your phone on and remove the connection in your phone.
Close BT on your phone again or shut it down.
Put in the OBD2 dongle in your car
Turn the radio on and set the PIN to 0000 or 1234 (depends on the dongle) There are no other possible PINs available, just one of these 2 written in here.
Search for the OBD2 and connect to it.
Start BT on your phone and search from the phone!!!
Enter the PIN as written and that´s it.
rigattoni said:
Will have a look tomorrow after the files for it to change.
Click to expand...
Click to collapse
Hi rigattoni,
By chance did you get around to looking at this?
Ok so I have installed a different chipset (oh and seems Klyde didn't even know what GPS chipset is in their unit, as it's not MT3337 as they advised), and the result is the same.
So it's a Android issue, maybe the location service NMEA data queue is not being cleared it refreshed fast enough. I don't know enough about Android to know how it works, but I gather the NMEA data from GNSS module is read and saved or queued somewhere, then this is read by the location.service routine when required.
I could also be that the GPVTG sentence is being dropped by Android, are the NMEA sentences accepted by Android location service filtered?
Can anyone help here where to look it's even possible with unrooted unit ?
Cheers,
Mal
rigattoni said:
You should use the GPS mouse which has been delivered with the unit, instead of using the OEM on the roof.
You would have the same behavior with most OEM installed GPS antennas, independent of the car.
Click to expand...
Click to collapse
Indeed I'm experiencing this problem (lag) while using an adapter and the OEM roof GPS antenna... Why is that?? It's a pity because OEM antenna is perfectly placed and concealed...
XxFraNxX said:
Indeed I'm experiencing this problem (lag) while using an adapter and the OEM roof GPS antenna... Why is that?? It's a pity because OEM antenna is perfectly placed and concealed...
Click to expand...
Click to collapse
I just know out of tests that I had the best results with the GPS mouse.
All external antennas I tested have been worse.
Hello,
I have exactly the same problem.
It's also from Klyde with a PX6.
Is there a solution?
Figo Emilio said:
Hello,
I have exactly the same problem.
It's also from Klyde with a PX6.
Is there a solution?
Click to expand...
Click to collapse
Solution for what?
GPS?
You should give some more information...
Exact unit number you buyed
MCU
Android version
Sorry.
A solution for the delayed GPS signal.
I Hope the Pics are ok?!